@article{elfering_metoyer_chatterjee_mazzoleni_bryant_granlund_2023, title={Blade element momentum theory for a skewed coaxial turbine}, volume={269}, ISSN={["1873-5258"]}, url={https://doi.org/10.1016/j.oceaneng.2022.113555}, DOI={10.1016/j.oceaneng.2022.113555}, abstractNote={A coaxial turbine under skew with significant rotor spacing has the potential for increased power output compared to a flow-aligned turbine due to a portion of the downstream rotor experiencing freestream velocity, referred to as a fresh flow region. A lab-scale prototype was designed and built to investigate the skew-to-power relationship of a coaxial turbine system as it compared to a blade element momentum theory model with multiple, sheared streamtubes representing the downstream rotor fresh flow region. The inclusion of the downstream rotor fresh flow region in the theoretical analysis is compared to the experimental data. The results support that the torque and power performance of the downstream rotor and overall skewed coaxial turbine system are predicted more accurately.}, journal={OCEAN ENGINEERING}, author={Elfering, Kelsey and Metoyer, Rodney and Chatterjee, Punnag and Mazzoleni, Andre and Bryant, Matthew and Granlund, Kenneth}, year={2023}, month={Feb} }
 @article{naik_beknalkar_reed_mazzoleni_fathy_vermillion_2023, title={Pareto Optimal and Dual-Objective Geometric and Structural Design of an Underwater Kite for Closed-Loop Flight Performance}, volume={145}, ISSN={["1528-9028"]}, DOI={10.1115/1.4055978}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Naik, Kartik and Beknalkar, Sumedh and Reed, James and Mazzoleni, Andre and Fathy, Hosam and Vermillion, Chris}, year={2023}, month={Jan} }
 @article{hassan_bryant_mazzoleni_ramaprabhu_granlund_2022, title={Analytical wake model for coaxial dual-rotor turbines}, ISBN={["978-1-6654-6809-1"]}, ISSN={["0197-7385"]}, DOI={10.1109/OCEANS47191.2022.9977241}, abstractNote={This work develops and validates a novel analytical wake model for coaxial dual-rotor turbines. With the diameters, and axial induction factors of the upstream and downstream rotors, and the freestream velocity, the proposed model estimates the wake velocity deficit in the near- and far-wake of the coaxial turbine. It is developed by utilizing the Bernoulli principle along the streamlines that pass through the near- and far-wake control volumes and the conservation laws for mass and momentum. This simple model can be used to calculate the velocity distribution in the wake using just one parameter. The wake prediction is contrasted with CFD results for various flow conditions to find good agreements between them. The novel wake model can be useful for solving the turbine farm layout optimization problem that involve dual-rotor configurations for the power generators.}, journal={2022 OCEANS HAMPTON ROADS}, author={Hassan, Mehedi and Bryant, Matthew and Mazzoleni, Andre and Ramaprabhu, Praveen and Granlund, Kenneth}, year={2022} }
 @article{abney_reed_naik_bryant_herbert_leonard_vadlamannati_mook_beknalkar_alvarez_et al._2022, title={Autonomous Closed-Loop Experimental Characterization and Dynamic Model Validation of a Scaled Underwater Kite}, volume={144}, ISSN={["1528-9028"]}, DOI={10.1115/1.4054141}, abstractNote={Abstract}, number={7}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Abney, Andrew and Reed, James and Naik, Kartik and Bryant, Samuel and Herbert, Dillon and Leonard, Zak and Vadlamannati, Ashwin and Mook, Mariah and Beknalkar, Sumedh and Alvarez, Miguel and et al.}, year={2022}, month={Jul} }
 @article{williams_bryant_agrawal_mazzoleni_granlund_ramaprabhu_bryant_2022, title={Characterization of the Steady-State Operating Conditions of Tethered Coaxial Turbines}, ISBN={["978-1-6654-6809-1"]}, ISSN={["0197-7385"]}, url={http://dx.doi.org/10.1109/oceans47191.2022.9977052}, DOI={10.1109/OCEANS47191.2022.9977052}, abstractNote={Tethered coaxial turbines (TCTs) may be a feasible configuration to extract hydrokinetic energy from the Gulf Stream’s flow. A TCT consists of two rotors attached to the halves of a rotary generator, which is moored to a mounting point via a tether. Flow causes the rotors to counter-rotate which induce power within the generator. The TCT’s steady-state operating domain and power extraction is determined by the intersection of the hydrodynamic operating domain of the rotors and electromechanic operating domain of the generator. As a result, the TCT’s operating point can be selected with an electrical load resistance, skew angle, and flow speed. Previous analytical methods for evaluating dual rotor devices have assumed ideal rotor, flow, and generator characteristics to simplify the quantification of power extraction. The proposed hydrodynamic analysis modifies traditional blade-element momentum theory (BEMT) to accept nonuniform inflow into the rotor, via a radially and azimuthally discretized BEMT method (RAD-BEMT). RAD-BEMT is leveraged alongside a momentum theory wake development factor to determine the response of the back rotor within the nonuniform wake of the front rotor. The back rotor response is determined by minimizing the difference in mass continuity and rotor torques. Our electromechanical analysis considers an AC generator, and the effects of voltage rectification, system resistance, and capacitance on the TCT’s power extraction capabilities. A case study was performed to demonstrate the ability of torque and mass continuity minimization to locate a hydrodynamic operating point, for axial and skew flow conditions. Additionally, power extraction capabilities, load resistance selection, and the qualitative effects of skew on the minimization domain are discussed.}, journal={2022 OCEANS HAMPTON ROADS}, publisher={IEEE}, author={Williams, Vinson Oliver and Bryant, Samuel and Agrawal, Saurabh and Mazzoleni, Andre P. and Granlund, Kenneth and Ramaprabhu, Praveen and Bryant, Matthew}, year={2022} }
 @article{beknalkar_naik_vermillion_mazzoleni_2022, title={Closed-Loop-Flight-Based Combined Geometric and Structural Wing Design Optimization Framework for a Marine Hydrokinetic Energy Kite}, ISBN={["978-1-6654-6809-1"]}, ISSN={["0197-7385"]}, DOI={10.1109/OCEANS47191.2022.9977369}, abstractNote={A marine hydrokinetic (MHK) kite offers an economical solution to the challenges of size and investment costs posed by the existing class of energy converters used to harvest tidal and ocean current energy. MHK kite systems are complicated devices that harvest ocean current energy by flying a tethered kite perpendicular to the motion of the current flow. They possess strong coupling between closed-loop flight control, geometric design, and structural design and hence it is important to consider all three facets simultaneously while designing a MHK kite system. Our previous work addressed this problem of simultaneous optimization of plant and controller through a control-aware optimization framework that fuses a geometric optimization tool, a structural optimization tool, and a closed-loop flight efficiency map. While our previous work analyzed the effect of key wing geometric parameters (wingspan and aspect ratio) on the performance of MHK kite systems, the present work represents the next crucial step in the study of ocean energy-harvesting kite systems and expands the design space to include several other wing geometric parameters - airfoil design, wing taper, wing twist, and dihedral angle. The effect of these decision variables on the power-to-mass ratio is estimated through an optimization framework based on a sequential approach. First, using sensitivity analysis, the framework determines which design variables in the design space affect the peak mechanical power generated while flying a cross-current path. In the next step, the combined geometric and structural optimization tool derives optimal values of variables in the reduced design space that results in a minimum structural mass. The constraints in the optimization problem include a lower limit on the peak power and limits on the number and dimensions of I-beam spars and the thickness of the wing shell. With a wing structure that can sustain peak lifting loads equal to less than a fixed value, the rest of the design variables are optimized to achieve maximum time-averaged power using medium-fidelity closed-loop-flight-based simulations. The final results of the optimization framework include an optimized wing geometry and wing structure with a maximized power-to-mass ratio for an MHK kite.}, journal={2022 OCEANS HAMPTON ROADS}, author={Beknalkar, Sumedh and Naik, Kartik and Vermillion, Chris and Mazzoleni, Andre}, year={2022} }
 @article{agrawal_williams_tong_hassan_muglia_bryant_granlund_ramaprabhu_mazzoleni_2022, title={Demonstration of a Towed Coaxial Turbine Subscale Prototype for Hydrokinetic Energy Harvesting in Skew}, ISBN={["978-1-6654-6809-1"]}, ISSN={["0197-7385"]}, url={http://dx.doi.org/10.1109/oceans47191.2022.9977395}, DOI={10.1109/OCEANS47191.2022.9977395}, abstractNote={The immense potential for ocean current energy harvesting is being actively explored by researchers, exhibiting the importance of the marine hydrokinetic industry. This paper presents a towed dual rotor coaxial turbine prototype built to demonstrate the ability of tethered, underwater, hydrokinetic devices to harvest energy from ocean currents. A sub-scale test article was developed to measure fluid power conversion and serve as a platform for operational feasibility in open-water testing. Tow testing of this article was done in the freshwaters of Lake Norman in North Carolina at three tow speeds: 1 m/s, 1.25 m/s and 1.5 m/s. Preliminary results demonstrate the ability to extract power, system robustness, waterproofing capabilities, and illuminates the nuances and non-linearities unique to the tethered coaxial turbine system.}, journal={2022 OCEANS HAMPTON ROADS}, publisher={IEEE}, author={Agrawal, Saurabh and Williams, Vinson Oliver and Tong, Xinyang and Hassan, Mehedi and Muglia, Mike and Bryant, Matthew and Granlund, Kenneth and Ramaprabhu, Praveen and Mazzoleni, Andre P.}, year={2022} }
 @article{warren_hey_mazzoleni_2022, title={Finite element study of the impact of pedicle screw density on the biomechanical response of a Lenke 1AN scoliotic curve}, volume={32}, ISSN={["0972-978X"]}, DOI={10.1016/j.jor.2022.05.012}, abstractNote={Benefits of increasing screw density in posterior instrumentation used to treat a scoliotic deformity are demonstrated using a three-dimensional finite element model (FEM) of the thoracolumbosacral spine. The FEM represents a Lenke 1AN scoliotic deformity with a 50° Cobb angle and 20° apical vertebral rotation. The curve is corrected with bilateral pedicle screw fixation and 75 separate randomized screw distributions. Total construct screw density, concave rod screw locations at T6, T10, T11 and T12, and convex rod screw locations at T7 and T12 each correlate strongly with reductions in postoperative Cobb angle (P < 0.05). Apical vertebral rotation is greatly impacted (reduced) by screws placed at the apical vertebra on both concave and convex rods (P < 0.05). Under pure moment loading, intersegmental micromotion is generally reduced when motion segment screw density is increased, with the exception being the upper instrumented joint. These results suggest that increasing the screw density of posterior constructs used to treat a Lenke 1AN scoliotic deformity may improve the de-rotation correction with better postural restoration, reducing the risk of future complications including pseudarthrosis.}, journal={JOURNAL OF ORTHOPAEDICS}, author={Warren, Justin M. and Hey, Lloyd A. and Mazzoleni, Andre P.}, year={2022}, pages={92–97} }
 @article{metoyer_bryant_granlundt_mazzoleni_2022, title={Increased Energy Conversion with a Horizontal Axis Turbine in Translation}, ISBN={["978-1-6654-6809-1"]}, ISSN={["0197-7385"]}, DOI={10.1109/OCEANS47191.2022.9977131}, abstractNote={When fixed to the ground by tower or stanchion, horizontal axis turbines convert hydrokinetic power into electric power by passively exploiting the difference in velocity between the ground and a flowing fluid. This method of converting the available hydrokinetic power is relatively simple, but the maximum amount of power that may be converted to another form by the turbine has a theoretical upper limit, called the Betz limit, which is about 59.25% of the hydrokinetic power in a stream tube of the freestream flow with a cross sectional area equal to the area of the turbine rotor plane. The work presented demonstrates that eschewing the stanchion and making the turbine to translate through the fluid enables conversion of more hydrokinetic power and, when operated in a cyclical mode, more energy over a cycle. It is demonstrated with momentum theory that the maximum energy that may be converted over a cycle is 1.5 times the Betz limit for an equivalent ground-fixed stationary turbine in the same low. Following the theoretical analysis, the concept is proven by simulation for a non-ideal turbine using an engineering design tool developed by the United States National Renewable Energy Laboratory. The results show that a realistic, non-ideal translating turbine can convert over twice as much power as an equivalent stationary turbine. Additionally, a notional tidal current application is presented where the bidirectionality of flow is exploited to achieve energy conversion of more than twice the theoretical limit of an ideal stationary turbine.}, journal={2022 OCEANS HAMPTON ROADS}, author={Metoyer, Rodney and Bryant, Matthew and Granlundt, Kenneth and Mazzoleni, Andre}, year={2022} }
 @article{yoder_agrawal_motes_mazzoleni_2021, title={Aerodynamic Tethered Sails for Scientific Balloon Trajectory Control: Small-Scale Experimental Demonstration}, volume={58}, ISSN={["1533-3868"]}, DOI={10.2514/1.C036057}, abstractNote={High-altitude scientific balloons are often prohibited from flying due to the risk associated with flying over populated areas. One solution to this problem is the use of a trajectory control syste...}, number={5}, journal={JOURNAL OF AIRCRAFT}, author={Yoder, Christopher D. and Agrawal, Saurabh and Motes, A. Gerrit and Mazzoleni, Andre P.}, year={2021}, month={Sep}, pages={1010–1021} }
 @article{parsons_mazzoleni_2021, title={Modeling and experimental investigation of the dynamics of a spherical Transforming Roving Rolling Explorer (TRREx) prototype}, volume={181}, ISSN={["1879-2030"]}, DOI={10.1016/j.actaastro.2020.12.023}, abstractNote={This paper examines a biologically inspired, transforming mars rover concept known as the Transforming Roving Rolling Explorer (TRREx). The rover is designed to operate in two modes: the ‘roving’ and ‘rolling’ modes. The roving mode is similar to many traditional wheeled rover designs and is useful for exploring relatively flat terrains. The rolling mode is intended to enable the rover to travel down steep slopes, such as those found in ravines and crater walls. In the rolling mode, the vehicle folds itself into a sphere and propels itself by shifting its center of mass. It does this by opening and closing the eight panels which form the surface of the sphere. The evaluation of this rolling mode is the primary focus of this paper. To that end, a spherical prototype TRREx has been designed, constructed, and tested. In addition, a mathematical model of the vehicle’s rolling mode dynamics has been created. The performance of the physical prototype has been compared to simulation results and the qualitative agreement between the experimental and simulated results indicate that the mathematical model created for the vehicle’s rolling mode dynamics captures the essential behavior of the vehicle. The mathematical simulation was then used to explore the TRREx parameter design space in order to analyze the effect of changing various system parameters. A path tracking simulation is also included as a case study to highlight the ability of a TRREx vehicle to traverse a desired path. • Spherical TRREx rover prototype built and used to validate math model of dynamics. • Rover prototype was able to self-propel by opening and closing its panels. • Parametric study conducted on the effect of design parameters on rover performance. • Increasing added-mass-to-chassis-mass ratio increases ability to climb slopes. • Rover was able to track an obstacle avoiding path by opening and closing its panels.}, journal={ACTA ASTRONAUTICA}, author={Parsons, John R. and Mazzoleni, Andre P.}, year={2021}, month={Apr}, pages={92–111} }
 @article{metoyer_chatterjee_elfering_bryant_granlund_mazzoleni_2021, title={Modeling, simulation, and equilibrium analysis of tethered coaxial dual-rotor ocean current turbines}, volume={243}, ISSN={["1879-2227"]}, DOI={10.1016/j.enconman.2021.113929}, abstractNote={Tethered multirotor axial flow turbines have been proposed to overcome the many challenges associated with extracting ocean current energy where deep waters render seabed mounting strategies infeasible. However, flexible systems are inherently more susceptible to perturbation than fixed systems. The effects of flow misalignment on the hydrokinetic energy conversion of multirotor coaxial turbines have been investigated recently; however, the spatial dynamics and equilibrium behaviors of tethered coaxial turbines have not been well characterized, limiting the ability of designers to explicitly tailor the device behavior. In this work, a computational model of a dual-rotor coaxial turbine is presented, and the model is employed to explore the equilibrium behavior of the turbine with variations in parameters. A complete characterization of the hydrostatic state of the system and a comparative study of representative tethered turbine simulation cases is also presented. Two important findings are presented. First, that a positively buoyant dual-rotor turbine that is anchored to a surface-dwelling platform can operate where the turbine is located at some desired depth below the surface. Second, that more than one turbine system may be anchored to a single point while maintaining the desired orientation and position of each turbine to avoid collision and maximize energy production. The results and methods presented in this paper may be used to inform application-specific coaxial turbine design and to develop additional targeted empirical and simulation studies.}, journal={ENERGY CONVERSION AND MANAGEMENT}, author={Metoyer, Rodney and Chatterjee, Punnag and Elfering, Kelsey and Bryant, Matthew and Granlund, Kenneth and Mazzoleni, Andre}, year={2021}, month={Sep} }
 @article{warren_mazzoleni_hey_2020, title={Development and Validation of a Computationally Efficient Finite Element Model of the Human Lumbar Spine: Application to Disc Degeneration}, volume={14}, ISSN={["2211-4599"]}, DOI={10.14444/7066}, abstractNote={ABSTRACT Introduction This study develops and validates an accurate, computationally efficient, 3-dimensional finite element model (FEM) of the human lumbar spine. Advantages of this simplified model are shown by its application to a disc degeneration study that we demonstrate is completed in one-sixth the time required when using more complicated computed tomography (CT) scan–based models. Methods An osseoligamentous FEM of the L1–L5 spine is developed using simple shapes based on average anatomical dimensions of key features of the spine rather than CT scan images. Pure moments of 7.5 Nm and a compressive follower load of 1000 N are individually applied to the L1 vertebra. Validation is achieved by comparing rotations and intradiscal pressures to other widely accepted FEMs and in vitro studies. Then degenerative disc properties are modeled and rotations calculated. Required computation times are compared between the model presented in this paper and other models developed using CT scans. Results For the validation study, parameter values for a healthy spine were used with the loading conditions described above. Total L1–L5 rotations for flexion, extension, lateral bending, and axial rotation under pure moment loading were calculated as 20.3°, 10.7°, 19.7°, and 10.3°, respectively, and under a compressive follower load, maximum intradiscal pressures were calculated as 0.68 MPa. These values compare favorably with the data used for validation. When studying the effects of disc degeneration, the affected segment is shown to experience decreases in rotations during flexion, extension, and lateral bending (24%–56%), while rotations are shown to increase during axial rotation (14%–40%). Adjacent levels realize relatively minor changes in rotation (1%–6%). This parametric study required 17.5 hours of computation time compared to more than 4 days required if utilizing typical published CT scan–based models, illustrating one of the primary advantages of the model presented in this article. Conclusions The FEM presented in this article produces a biomechanical response comparable to widely accepted, complex, CT scan–based models and in vitro studies while requiring much shorter computation times. This makes the model ideal for conducting parametric studies of spinal pathologies and spinal correction techniques.}, number={4}, journal={INTERNATIONAL JOURNAL OF SPINE SURGERY}, author={Warren, Justin M. and Mazzoleni, Andre P. and Hey, Lloyd A.}, year={2020}, month={Aug}, pages={502–510} }
 @article{sardeshmukh_yoder_talaski_mazzoleni_2020, title={Mathematical modeling and parametric study of a planar Tumbleweed rover demonstrator}, volume={177}, ISSN={["1879-2030"]}, DOI={10.1016/j.actaastro.2020.06.035}, abstractNote={Spherical wind-blown Tumbleweed rovers have the potential to significantly expand the type of interplanetary terrain that can be explored on planets such as Mars. Multiple tumbleweed designs have been studied by NASA’s Langley Research Center and Jet Propulsion Laboratory, and one promising design, the box-kite model, relies on internal sails to maneuver over rough terrains with the help of mass actuation within the rover chassis for directional control. This paper sets out to parametrically study the effect of actuating masses on Tumbleweed rover performance. As a first step towards evaluating the performance of a spherical Tumbleweed rover, we study a planar model in this paper. To accomplish our parametric study, a dynamic model and control scheme for a planar tumbleweed rover has been developed with four moving masses within the structure, and a prototype was built based on the model and proposed control scheme. The prototype was used to establish the validity of the dynamic model, and the dynamic model was then used to study the effect of rover diameter, mass actuation speed, and chassis-mass-to-actuating-mass ratios on the performance of the tumbleweed rover. From these studies it was found that the final angular speed of the rover decreases with increasing rover diameter, while the rover linear speed increases with diameter. The time taken to reach a desired angular speed was found to increase with increasing rover diameter for all cases. Additionally, final rover angular speed and linear speed were shown to increase with actuating-mass-to-chassis-mass ratio, and the time taken for reaching a desired angular speed and linear speed, i.e. settling time, was found to decrease with increasing actuating-mass-to-chassis-mass ratio.}, journal={ACTA ASTRONAUTICA}, author={Sardeshmukh, Paurav A. and Yoder, Christopher D. and Talaski, Daria J. and Mazzoleni, Andre P.}, year={2020}, month={Dec}, pages={48–57} }
 @article{waghela_yoder_gopalarathnam_mazzoleni_2019, title={Aerodynamic Sails for Passive Guidance of High-Altitude Balloons: Static-Stability and Equilibrium Performance}, volume={56}, ISSN={["1533-3868"]}, DOI={10.2514/1.C035353}, abstractNote={Balloon trajectory control remains a sought-after goal for the current scientific ballooning community. In this work, a trajectory control system capable of passively guiding a high-altitude balloo...}, number={5}, journal={JOURNAL OF AIRCRAFT}, author={Waghela, R. and Yoder, C. D. and Gopalarathnam, A. and Mazzoleni, A. P.}, year={2019}, pages={1849–1857} }
 @article{khatri_chatterjee_metoyer_mazzoleni_bryant_granlund_2019, title={Dual-Actuator Disc Theory for Turbines in Yaw}, volume={57}, ISSN={["1533-385X"]}, DOI={10.2514/1.J057740}, abstractNote={No AccessTechnical NotesDual-Actuator Disc Theory for Turbines in YawDheepak N. Khatri, Punnag Chatterjee, Rodney Metoyer, Andre P. Mazzoleni, Matthew Bryant and Kenneth O. GranlundDheepak N. KhatriNorth Carolina State University, Raleigh, North Carolina 27695*Graduate Research Assistant, Department of Mechanical and Aerospace Engineering.Search for more papers by this author, Punnag ChatterjeeNorth Carolina State University, Raleigh, North Carolina 27695*Graduate Research Assistant, Department of Mechanical and Aerospace Engineering.Search for more papers by this author, Rodney MetoyerNorth Carolina State University, Raleigh, North Carolina 27695*Graduate Research Assistant, Department of Mechanical and Aerospace Engineering.Search for more papers by this author, Andre P. MazzoleniNorth Carolina State University, Raleigh, North Carolina 27695†Associate Professor, Department of Mechanical and Aerospace Engineering. Associate Fellow AIAA.Search for more papers by this author, Matthew BryantNorth Carolina State University, Raleigh, North Carolina 27695‡Assistant Professor, Department of Mechanical and Aerospace Engineering.Search for more papers by this author and Kenneth O. GranlundNorth Carolina State University, Raleigh, North Carolina 27695§Assistant Professor, Department of Mechanical and Aerospace Engineering. Senior Member AIAA.Search for more papers by this authorPublished Online:23 Jan 2019https://doi.org/10.2514/1.J057740SectionsRead Now ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail About References [1] Betz A., “Das Maximum der theoretisch möglichen Ausnützung des Windes durch Windmotoren,” Zeitschrift für das gesamte Turbinenwesen, 1920, pp. 26, 307–309. Google Scholar[2] Newman B. G., “Actuator Disc Theory for Vertical Wind Turbines,” Journal of Wind Engineering and Industrial Aerodynamics, Vol. 15, Nos. 1–3, 1983, pp. 347–355. doi:https://doi.org/10.1016/0167-6105(83)90204-0 JWEAD6 0167-6105 CrossrefGoogle Scholar[3] Rosenberg A., Selvaraj S. and Sharma A., “A Novel Dual-Rotor Turbine for Increased Wind Energy Capture,” Journal of Physics: Conference Series, Vol. 524, 2014, Paper 012078. doi:https://doi.org/10.1088/1742-6596/524/1/012078 JPCSDZ 1742-6588 CrossrefGoogle Scholar[4] Adams Z. and Chen J., “Flux-Line Theory: A Novel Analytical Model for Cycloturbines,” AIAA Journal, Vol. 55, No. 11, 2017, pp. 3851–3867. doi:https://doi.org/10.2514/1.J055804 AIAJAH 0001-1452 LinkGoogle Scholar[5] Anderson M., “Horizontal Axis Wind Turbines in Yaw,” Proceedings of the First British Wind Energy Association (BWEA) Wind Energy Workshop, 1979, pp. 57–67, http://adsabs.harvard.edu/abs/1979wien.work...57A. Google Scholar[6] Grant I., Parkin P. and Wang X., “Optical Vortex Tracking Studies of a Horizontal Axis Wind Turbine in Yaw Using Laser-Sheet, Flow Visualization,” Experiments in Fluids, Vol. 23, No. 6, 1997, pp. 513–519. doi:https://doi.org/10.1007/s003480050142 EXFLDU 0723-4864 CrossrefGoogle Scholar[7] Newman B. G., “Multiple Actuator Disc Theory for Wind Turbines,” Journal of Wind Engineering and Industrial Aerodynamics, Vol. 24, No. 3, 1986, pp. 215–225. doi:https://doi.org/10.1016/0167-6105(86)90023-1 JWEAD6 0167-6105 CrossrefGoogle Scholar[8] Howland M., Bossuyt J., Martinez-Tossas L., Meyers J. and Meneveau C., “Wake Structure in Actuator Disk Models of Wind Turbines in Yaw Under Uniform Inflow Conditions,” Journal of Renewable and Sustainable Energy, Vol. 8, No. 4, 2016, Paper 043301. doi:https://doi.org/10.1063/1.4955091 CrossrefGoogle Scholar Previous article Next article FiguresReferencesRelatedDetailsCited byPool-Based Tow System for Testing Tethered Hydrokinetic Devices Being Developed to Harvest Energy From Ocean CurrentsMarine Technology Society Journal, Vol. 57, No. 1Blade element momentum theory for a skewed coaxial turbineOcean Engineering, Vol. 269Closed-Loop-Flight-Based Combined Geometric and Structural Wing Design optimization Framework for a Marine Hydrokinetic Energy KiteDemonstration of a Towed Coaxial Turbine Subscale Prototype for Hydrokinetic Energy Harvesting in SkewCharacterization of the Steady-State Operating Conditions of Tethered Coaxial TurbinesIncreased Energy Conversion with a Horizontal Axis Turbine in TranslationModeling, simulation, and equilibrium analysis of tethered coaxial dual-rotor ocean current turbinesEnergy Conversion and Management, Vol. 243Experimental analysis of dual coaxial turbines in skewOcean Engineering, Vol. 215 What's Popular Volume 57, Number 5May 2019 CrossmarkInformationCopyright © 2018 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. All requests for copying and permission to reprint should be submitted to CCC at www.copyright.com; employ the eISSN 1533-385X to initiate your request. See also AIAA Rights and Permissions www.aiaa.org/randp. TopicsAerodynamicsAeronautical EngineeringAeronauticsConservation of Momentum EquationsEnergyEnergy FormsEnergy Forms, Production and ConversionEquations of Fluid DynamicsFlow RegimesFluid DynamicsFluid Flow PropertiesTurbinesTurbomachineryWind EngineeringWind Turbine KeywordsTurbinesYawConservation of MassHorizontal Axis TurbineFree Stream VelocityConservation EquationsTwo Dimensional FlowNavier Stokes EquationsKinetic EnergyFluid DensityAcknowledgmentsThis work was funded by a grant from the North Carolina Coastal Studies Institute. The authors would like to thank undergraduate research assistants Tyler Farr and Kyle Weiner for their contributions to these results.PDF Received27 August 2018Accepted2 December 2018Published online23 January 2019}, number={5}, journal={AIAA JOURNAL}, author={Khatri, Dheepak N. and Chatterjee, Punnag and Metoyer, Rodney and Mazzoleni, Andre P. and Bryant, Matthew and Granlund, Kenneth O.}, year={2019}, month={May}, pages={2204–2208} }
 @article{tandon_divi_muglia_vermillion_mazzoleni_2019, title={Modeling and dynamic analysis of a mobile underwater turbine system for harvesting Marine Hydrokinetic Energy}, volume={187}, ISSN={["0029-8018"]}, DOI={10.1016/j.oceaneng.2019.05.051}, abstractNote={We present the modeling and dynamic analysis of a Mobile Underwater Turbine System, a novel integration of Autonomous Underwater Vehicles and Hydrokinetic Turbines, for harvesting Marine Hydrokinetic Energy from the Gulf Stream. The Gulf Stream, an ocean current that flows off the coast of North Carolina, is a source of hydrokinetic energy. However, the meandering nature of the Gulf Stream makes it challenging to harvest the full energy potential of the stream using fixed turbine systems. One possible solution for increasing the amount of energy that can be extracted from the Gulf Stream involves using a mobile underwater energy harvester system that can follow the meandering stream so as to remain in regions of maximum energy potential. The framework for the conceptual design, and studies focusing on the feasibility of such a system, have been presented previously in (Divi, 2017). The focus of this paper is a mathematical model of the system which has been developed to analyze the dynamics of such a system, along with parametric studies utilizing this model to come up with a system with an optimized set of design parameters. A 6-DOF analytical model of the system is developed to gain an understanding of the system's dynamic behavior and stability. A bead-based tether model is further developed to analyze the behavior of the system when it is anchored and harvesting energy. A study regarding the effects of tether parameters such as the number of tether elements, the spring constant, and the damping coefficient of the tether on the tether behavior and computation time required for analysis, is put forth to help determine an optimal set of tether parameters. In addition, a set of system parameters such as turbine diameter, hull diameter, L/D ratio of the hull and ballast tank size, are analyzed to see how they affect the net energy produced and the maximum distance travelled by the system. Finally, three modes of power transfer to the shore are considered, and an optimization algorithm is presented and used to find the best set of parameters suited for maximum energy transfer for each mode.}, journal={Ocean Engineering}, author={Tandon, Shubham and Divi, Sathvik and Muglia, Michael and Vermillion, Chris and Mazzoleni, Andre}, year={2019}, month={Sep}, pages={106069} }
 @article{yoder_gemmer_mazzoleni_2019, title={Modelling and performance analysis of a tether and sail-based trajectory control system for extra-terrestrial scientific balloon missions}, volume={160}, ISSN={["1879-2030"]}, DOI={10.1016/j.actaastro.2018.12.030}, abstractNote={Balloon systems show great promise for exploring the atmospheres of extra-terrestrial bodies in the solar system. The balloon system concept was demonstrated by the aerostats aboard the Vega 1 and 2 missions sent to Venus. Such systems glean propulsion from atmospheric winds, and at present are unable to travel in a direction perpendicular to the direction of the wind, limiting their exploration potential. A control system capable of modifying the system trajectory by traveling in a direction perpendicular to the direction of the wind is desired to increase exploration potential as well as to perform tasks such as maintaining latitude. A balloon and sail system which can use wind velocity and density gradients to produce a guiding force perpendicular to the velocity of the wind is discussed here. Such a guidance system is passive in nature and requires little power for actuation and control. It was previously demonstrated that such a control system is capable of generating guiding velocities of several meters per second within the Venusian atmosphere. Furthermore, this control system was shown to be capable of achieving sufficient control for the majority of the latitudes on Venus. This work builds on previous results and demonstrates the benefits of being able to generate guiding velocities via a sail system by viewing the trajectories taken by planetary balloon systems employing such a system. First, a description of the system model is given. Next, for the atmospheres of Venus and Titan, trajectory control is demonstrated for various sail parameters, such as sail size and mass. The benefit of such control is shown by the ability to achieve various latitudes of interest for a given flight duration. These latitudes are chosen based on geographic features, such as lakes on Titan. Finally, a PI controller is added to the model to demonstrate rudimentary control of the balloon system for maintaining and changing latitudes. A brief discussion regarding the control law of the system is also provided.}, journal={ACTA ASTRONAUTICA}, author={Yoder, Christopher D. and Gemmer, Thomas R. and Mazzoleni, Andre P.}, year={2019}, month={Jul}, pages={527–537} }
 @article{edwin_mazzoleni_gemmer_ferguson_2017, title={Modeling, construction and experimental validation of actuated rolling dynamics of the cylindrical Transforming Roving-Rolling Explorer (TRREx)}, volume={132}, ISSN={0094-5765}, url={http://dx.doi.org/10.1016/J.ACTAASTRO.2016.11.006}, DOI={10.1016/J.ACTAASTRO.2016.11.006}, abstractNote={Planetary surface exploration technology over the past few years has seen significant advancements on multiple fronts. Robotic exploration platforms are becoming more sophisticated and capable of embarking on more challenging missions. More unconventional designs, particularly transforming architectures that have multiple modes of locomotion, are being studied. This work explores the capabilities of one such novel transforming rover called the Transforming Roving-Rolling Explorer (TRREx). Biologically inspired by the armadillo and the golden-wheel spider, the TRREx has two modes of locomotion: it can traverse on six wheels like a conventional rover on benign terrain, but can transform into a sphere when necessary to negotiate steep rugged slopes. The ability to self-propel in the spherical configuration, even in the absence of a negative gradient, increases the TRREx's versatility and its concept value. This paper describes construction and testing of a prototype cylindrical TRREx that demonstrates that “actuated rolling” can be achieved, and also presents a dynamic model of this prototype version of the TRREx that can be used to investigate the feasibility and value of such self-propelled locomotion. Finally, we present results that validate our dynamic model by comparing results from computer simulations made using the dynamic model to experimental results acquired from test runs using the prototype.}, journal={Acta Astronautica}, publisher={Elsevier BV}, author={Edwin, L. and Mazzoleni, A. and Gemmer, T. and Ferguson, S.}, year={2017}, month={Mar}, pages={43–53} }
 @article{gemmer_yoder_reedy_mazzoleni_2017, title={Tether enabled spacecraft systems for ultra long wavelength radio astronomy}, volume={138}, ISSN={["1879-2030"]}, DOI={10.1016/j.actaastro.2016.11.009}, abstractNote={This paper describes a proposed CubeSat mission to perform unique experiments involving interferometry and tether dynamics. A 3U CubeSat is to be placed in orbit where it will separate into three 1U CubeSats connected by a total of 100 m of tether. The separation between the three units will allow for the demonstration of high resolution radio interferometry. The increased resolution will provide access to the Ultra-Long Wavelength (ULW) scale of the electromagnetic spectrum, which is largely unexplored. During and after completion of the primary experiment, the CubeSat will be able to gather data on tethered dynamics of a space vehicle. Maneuvers to be performed and studied include direct testing of tether deployment and tethered formation flying. Tether deployment is a vital area where more data is needed as this is the phase where many tethered missions have experienced complications and failures. There are a large number of complex dynamical responses predicted by the theory associated with the deployment of an orbiting tethered system. Therefore, it is imperative to conduct an experiment that provides data on what dynamic responses actually occur.}, journal={ACTA ASTRONAUTICA}, author={Gemmer, Thomas and Yoder, Christopher D. and Reedy, Jacob and Mazzoleni, Andre P.}, year={2017}, month={Sep}, pages={530–535} }
 @article{edwin_mazzoleni_2016, title={Dynamic modeling and mobility analysis of the transforming roving-rolling explorer (TRREx) as it Traverses Rugged Martian Terrain}, volume={120}, ISSN={["1879-2030"]}, DOI={10.1016/j.actaastro.2015.10.017}, abstractNote={All planetary surface exploration missions thus far have employed traditional rovers with a rocker-bogie suspension. These rovers can navigate moderately rough and flat terrain, but are not designed to traverse rugged terrain with steep slopes. The fact is, however, that the most scientifically interesting missions require exploration platforms with capabilities for navigating such types of rugged terrain. This issue motivates the development of new kinds of rovers that take advantage of the latest advances in robotic technologies to traverse rugged terrain efficiently. This work analyzes one such rover concept called the Transforming Roving–Rolling Explorer (TRREx) that is principally aimed at addressing the above issue. Biologically inspired by the way the armadillo curls up into a ball when threatened, and the way the golden wheel spider uses the dynamic advantages of a sphere to roll down hills when escaping danger, the TRREx rover can traverse like a traditional 6-wheeled rover over conventional terrain, but can also transform itself into a sphere, when necessary, to travel down steep inclines, or navigate rough terrain. This paper investigates the mobility of the TRREx when it is in its rolling mode, i.e. when it is a sphere and can steer itself through actuations that shift its center of mass to achieve the desired direction of roll. A mathematical model describing the dynamics of the rover in this spherical configuration is presented, and actuated rolling is demonstrated through computer simulation. Parametric analyzes that investigate the rover’s mobility as a function of its design parameters are also presented. This work highlights the contribution of the spherical rolling mode to the enhanced mobility of the TRREx rover and how it could enable challenging surface exploration missions in the future.}, journal={ACTA ASTRONAUTICA}, author={Edwin, Lionel E. and Mazzoleni, Andre P.}, year={2016}, pages={103–120} }
 @article{jung_mazzoleni_chung_2015, title={Nonlinear dynamic analysis of a three-body tethered satellite system with deployment/retrieval}, volume={82}, ISSN={["1573-269X"]}, DOI={10.1007/s11071-015-2221-z}, number={3}, journal={NONLINEAR DYNAMICS}, author={Jung, Wonyoung and Mazzoleni, Andre P. and Chung, Jintai}, year={2015}, month={Nov}, pages={1127–1144} }
 @article{padgett_mazzoleni_faw_2015, title={Survey of shock wave structures of smooth particle granular flows}, volume={92}, ISSN={["1550-2376"]}, DOI={10.1103/physreve.92.062209}, abstractNote={We show the effects of simulated supersonic granular flow made up of smooth particles passing over two prototypical bodies: a wedge and a disk. We describe a way of computationally identifying shock wave locations in granular flows and tabulate the shock wave locations for flow over wedges and disks. We quantify the shock structure in terms of oblique shock angle for wedge impediments and shock standoff distance for disk impediments. We vary granular flow parameters including upstream volume fraction, average upstream velocity, granular temperature, and the collision coefficient of restitution. Both wedges and disks have been used in the aerospace community as prototypical impediments to flowing air in order to investigate the fundamentally different shock structures emanating from sharp and blunt bodies, and we present these results in order to increase the understanding of the fundamental behavior of supersonic granular flow.}, number={6}, journal={Physical Review E}, author={Padgett, D. A. and Mazzoleni, A.P. and Faw, Stormy D.}, year={2015}, month={Dec}, pages={062209} }
 @inproceedings{denhart_gemmer_ferguson_mazzoleni_2014, title={A concept selection framework for early sorting of reconfigurable system designs}, DOI={10.1115/detc2013-13222}, abstractNote={A seven-step framework for sorting proposed concepts of system changes / reconfigurations is presented that seeks to characterize the overall ramifications on system architecture. This framework is intended for use immediately following a concept generation phase. The framework uses three simple questions: “What level of the system design does this concept apply to?” “What levels of the system design does the concept impact?” and “What is the severity of this impact?” A flowchart leads the designer through these questions and assigns each concept a classification from one to five based on the answers. Class one concepts have little to no impact on the rest of the system architecture. They can be included with little fear of massive change propagation and system redesign. Class five concepts carry large changes to system architecture and therefore should be included only if they can be shown to be highly beneficial, or if there remains enough design freedom such that the cost of changing the system architecture is minimal. Meanwhile, class five concepts are likely to have much higher potential to create revolutionary design. A case study is used to demonstrate the application of the sorting framework in the context of a Mars rover mission. Several example concepts are provided to illustrate key insights from the case study. Convergence of the framework is explored by comparing the authors’ results to a second test done by a new design team.}, booktitle={Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, 2013, vol 3B}, author={Denhart, J. and Gemmer, T. and Ferguson, S. and Mazzoleni, A.}, year={2014} }
 @article{park_ro_he_mazzoleni_2014, title={Analysis, Fabrication, and Testing of a Liquid Piston Compressor Prototype for an Ocean Compressed Air Energy Storage (OCAES) System}, volume={48}, ISSN={["1948-1209"]}, DOI={10.4031/mtsj.48.6.3}, abstractNote={AbstractPrevious work concerning ocean compressed air energy storage (OCAES) systems has revealed the need for an efficient means for compressing air that minimizes the energy lost to heat during the compression process. In this paper, we present analysis, simulation, and
 testing of a tabletop proof-of-concept experiment of a liquid piston compression system coupled with a simulated OCAES system, with special attention given to heat transfer issues. An experimental model of a liquid piston system was built and tested with two different materials, polycarbonate
 and aluminum alloy, used for the compression chamber. This tabletop liquid piston system was tested in conjunction with a simulated OCAES system, which consisted of a hydrostatic tank connected to a compressed-air source from the wall to mimic the constant hydrostatic pressure at ocean depth
 experienced by the air stored in an actual OCAES system. Good agreement was found between the experimental and numerical studies and demonstrated that the heat transfer characteristics of a liquid piston compression process are effective in reducing the increase in air temperature that occurs
 during the compression process. The results also suggest that it may be possible to achieve a near-isothermal process with a fully optimized liquid piston compression system.}, number={6}, journal={Marine Technology Society Journal}, author={Park, J. and Ro, P. and He, X. and Mazzoleni, A.}, year={2014}, pages={86–97} }
 @article{jung_mazzoleni_chung_2014, title={Dynamic analysis of a tethered satellite system with a moving mass}, volume={75}, ISSN={["1573-269X"]}, DOI={10.1007/s11071-013-1064-8}, number={1-2}, journal={NONLINEAR DYNAMICS}, author={Jung, Wonyoung and Mazzoleni, Andre P. and Chung, Jintai}, year={2014}, month={Jan}, pages={267–281} }
 @article{french_mazzoleni_2014, title={Modeling tether–ballast asteroid diversion systems, including tether mass and elasticity}, volume={103}, ISSN={0094-5765}, url={http://dx.doi.org/10.1016/j.actaastro.2014.04.014}, DOI={10.1016/j.actaastro.2014.04.014}, abstractNote={Abstract The risk of an impact between a large asteroid and the Earth has been significant enough to attract the attention of many researchers. This paper focuses on a mitigation technique that involves the use of a long tether and ballast mass to divert an asteroid. When such a tether is modeled as massless and inelastic, results show that the method may be viable for diverting asteroids away from a collision with the Earth; the next step towards demonstrating the viability of the approach is to conduct a study which uses a more realistic tether model. This paper presents such a study, in which the tether models include tether mass and elasticity. These models verify that a tether–ballast system is capable of diverting Earth-threatening asteroids. Detailed parametric studies are presented which illustrate how system performance depends on tether mass and elasticity. Also, case studies are presented which show how more realistic models can aid in the design of tether–ballast asteroid mitigation systems. Key findings include the dangers imposed by periods during which the tether goes slack and ways to preclude this.}, journal={Acta Astronautica}, publisher={Elsevier BV}, author={French, David B. and Mazzoleni, Andre P.}, year={2014}, month={Oct}, pages={282–306} }
 @article{edwin_denhart_gemmer_ferguson_mazzoleni_2014, title={Performance Analysis and Technical Feasibility Assessment of a Transforming Roving-Rolling Explorer Rover for Mars Exploration}, volume={136}, ISSN={["1050-0472"]}, DOI={10.1115/1.4027336}, abstractNote={This paper explores a two state rover concept called the Transforming Roving-Rolling Explorer (TRREx). The first state allows the rover to travel like a conventional 6-wheeled rover. The second state is a sphere to permit faster descent of steep inclines. Performance of this concept is compared to a traditional rocker-bogie (RB) architecture using hi-fidelity simulations in Webots. Results show that for missions involving very rugged terrain, or a considerable amount of downhill travel, the TRREx outperforms the rocker-bogie. Locomotion of the TRREx system using a continuous shifting of the center of mass through “actuated rolling” is also explored. A dynamics model for a cylindrical representation of the rover is simulated to identify feasible configurations capable of generating and maintaining continuous rolling motion even on sandy terrain. Results show that in sufficiently benign terrain gradual inclines can be traversed with actuated rolling. This model allows for increased exploration of the problem's design space and assists in establishing parameters for an Earth prototype.}, number={7}, journal={JOURNAL OF MECHANICAL DESIGN}, author={Edwin, Lionel E. and Denhart, Jason D. and Gemmer, Thomas R. and Ferguson, Scott M. and Mazzoleni, Andre P.}, year={2014}, month={Jul} }
 @article{lee_mazzoleni_zikry_2013, title={Aerodynamic effects on the accuracy of an end-over-end kick of an American football}, volume={16}, ISSN={1369-7072 1460-2687}, url={http://dx.doi.org/10.1007/S12283-012-0110-Y}, DOI={10.1007/S12283-012-0110-Y}, number={2}, journal={Sports Engineering}, publisher={Springer Science and Business Media LLC}, author={Lee, W. M. and Mazzoleni, A. P. and Zikry, M. A.}, year={2013}, month={Feb}, pages={99–113} }
 @article{lim_mazzoleni_park_ro_quinlan_2013, title={Conceptual Design of Ocean Compressed Air Energy Storage System}, volume={47}, ISSN={["1948-1209"]}, DOI={10.4031/mtsj.47.2.5}, abstractNote={AbstractIn this paper, an ocean compressed air energy storage (OCAES) system is introduced as a utility-scale energy storage option for electricity generated by wind, ocean currents, tides, and waves off the coast of North Carolina. Geographically, a location from 40 to 70
 km off the coast of Cape Hatteras is shown to be a good location for an OCAES system. Building upon existing compressed air energy storage (CAES) system designs, a conceptual design of an OCAES system with thermal energy storage (TES) is presented. A simple thermodynamic analysis is presented
 for an adiabatic CAES system which shows that the overall efficiency is 66%. In addition, finite element simulations are presented, which show the flow induced loads that will be experienced by OCAES air containers on the ocean floor. We discuss the fact that the combination of the buoyancy
 force and flow-induced lift forces (due to ocean currents) generates a periodic loading on the storage container and seabed, and how this presents engineering challenges related to the development of methods for reliably resisting these loads for decades in a corrosive environment. We also
 present a system, based on hydrolysis, which can be used for storing energy (in the form of oxygen and hydrogen gas) in containers on the ocean floor.}, number={2}, journal={MARINE TECHNOLOGY SOCIETY JOURNAL}, author={Lim, Saniel D. and Mazzoleni, Andre P. and Park, Joong-kyoo and Ro, Paul I. and Quinlan, Brendan}, year={2013}, pages={70–81} }
 @article{hartl_miller_mazzoleni_2013, title={Dynamics of a dissipative, inelastic gravitational billiard}, volume={87}, ISSN={["1550-2376"]}, DOI={10.1103/physreve.87.032901}, abstractNote={The seminal physical model for investigating formulations of nonlinear dynamics is the billiard. Gravitational billiards provide an experimentally accessible arena for their investigation. We present a mathematical model that captures the essential dynamics required for describing the motion of a realistic billiard for arbitrary boundaries, where we include rotational effects and additional forms of energy dissipation. Simulations of the model are applied to parabolic, wedge and hyperbolic billiards that are driven sinusoidally. The simulations demonstrate that the parabola has stable, periodic motion, while the wedge and hyperbola (at high driving frequencies) appear chaotic. The hyperbola, at low driving frequencies, behaves similarly to the parabola; i.e., has regular motion. Direct comparisons are made between the model’s predictions and previously published experimental data. The representation of the coefficient of restitution employed in the model resulted in good agreement with the experimental data for all boundary shapes investigated. It is shown that the data can be successfully modeled with a simple set of parameters without an assumption of exotic energy dependence.}, number={3}, journal={PHYSICAL REVIEW E}, author={Hartl, Alexandre E. and Miller, Bruce N. and Mazzoleni, Andre P.}, year={2013}, month={Mar} }
 @inproceedings{park_ro_lim_mazzoleni_quinlan_2012, title={Analysis and optimization of a quasi-isothermal compression and expansion cycle for Ocean Compressed Air Energy Storage (OCAES)}, DOI={10.1109/oceans.2012.6404964}, abstractNote={A numerical analysis of a quasi-isothermal thermodynamic cycle was undertaken for its application in an underwater energy storage system. The conceptual basis for the quasi-isothermal process is firstly a use of water pistons, as opposed to air or other gas medium, which improve heat transfer rate and minimize the temperature variation on both compression and expansion sides of the cycle and secondly a use of mechanical design that maximizes a surface area of heat transfer. Numerical analysis of the heat transfer cycle confirms the validity of the quasi-isothermal nature of the water pistons. Design factors such as surface area, stroke displacement, and frequency of piston action can be analyzed for optimality. For a case study, a recent commercial design of the quasi-isothermal process is introduced and partially analyzed for its effectiveness. Impact of varying several design factors have been analyzed numerically for further understanding of optimality and for validating the quasi-isothermal nature of the design.}, booktitle={2012 Oceans}, author={Park, J. K. and Ro, P. I. and Lim, S. D. and Mazzoleni, A. P. and Quinlan, B.}, year={2012} }
 @inproceedings{lim_mazzoleni_park_ro_quinlan_2012, title={Conceptual design of ocean compressed air energy storage system}, DOI={10.1109/oceans.2012.6404909}, abstractNote={In this paper, an ocean compressed air energy storage (OCAES) system is introduced as a utility scale energy storage option for electricity generated by wind, ocean currents, tides, and waves off the coast of North Carolina. Geographically, a location from 40km to 70km off the coast of Cape Hatteras is shown to be a good location for an OCAES system. Based on existing compressed air energy storage (CAES) system designs, a conceptual design of an OCAES system with thermal energy storage (TES) is presented. A simple thermodynamic analysis is presented for an adiabatic CAES system which shows that the overall efficiency is 65.9%. In addition, finite element simulations are presented which show the flow induced loads which will be experienced by OCAES air containers on the ocean floor. We discuss the fact that the combination of the buoyancy force and the flow induced lift forces (due to ocean currents) generates a periodic loading on the storage container and seabed, and how this presents engineering challenges related to the development of adequate anchoring systems. We also present a system, based on hydrolysis, which can be used for storing energy (in the form of oxygen and hydrogen gas) in containers on the ocean floor.}, booktitle={2012 Oceans}, author={Lim, S. D. and Mazzoleni, A. P. and Park, J. K. and Ro, P. I. and Quinlan, B.}, year={2012} }
 @article{hartl_mazzoleni_2012, title={Terrain modeling and simulation of a tumbleweed rover traversing martian rock fields}, volume={49}, DOI={10.2514/1.57903}, abstractNote={Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.}, number={2}, journal={Journal of Spacecraft and Rockets}, author={Hartl, A. E. and Mazzoleni, A. P.}, year={2012}, pages={401–412} }
 @article{hartl_miller_mazzoleni_2011, title={Dynamic modeling and simulation of a real world billiard}, volume={375}, ISSN={["1873-2429"]}, DOI={10.1016/j.physleta.2011.08.038}, abstractNote={Gravitational billiards provide an experimentally accessible arena for testing formulations of nonlinear dynamics. We present a mathematical model that captures the essential dynamics required for describing the motion of a realistic billiard for arbitrary boundaries. Simulations of the model are applied to parabolic, wedge and hyperbolic billiards that are driven sinusoidally. Direct comparisons are made between the modelʼs predictions and previously published experimental data. It is shown that the data can be successfully modeled with a simple set of parameters without an assumption of exotic energy dependence.}, number={42}, journal={PHYSICS LETTERS A}, author={Hartl, Alexandre E. and Miller, Bruce N. and Mazzoleni, Andre P.}, year={2011}, month={Oct}, pages={3682–3686} }
 @article{hartl_mazzoleni_2010, title={Dynamic Modeling of a Wind-Driven Tumbleweed Rover Including Atmospheric Effects}, volume={47}, ISSN={["0022-4650"]}, DOI={10.2514/1.45174}, abstractNote={A tumbleweed rover is a spherical wind-driven rover designed to explore places of geological interest on the Martian surface. Dynamic models developed for an individual rover are used to create numerical simulations for a rover traversing through flat terrain, a channel, and a crater. The simulations show that the rover’s motion is dependent on the terrain type and initial and atmospheric conditions. The results confirm that the wind force both pushes and hinders the rover’s motion while sliding, rolling, and bouncing. The rover periodically transitions between these modes of movement when contact is initiated against sloped portions of terrain. Combinations of rolling and bouncing may be a more effective means of transport for a rover traveling through a channel when compared to rolling alone. The aerodynamic effects of drag and the Magnus force are contributing factors to the possible capture of the rover by a crater.}, number={3}, journal={JOURNAL OF SPACECRAFT AND ROCKETS}, author={Hartl, Alexandre E. and Mazzoleni, Andre P.}, year={2010}, pages={493–502} }
 @article{french_mazzoleni_2009, title={Asteroid Diversion Using a Long Tether and Ballast}, volume={46}, ISSN={["0022-4650"]}, DOI={10.2514/1.40828}, abstractNote={The threat of an asteroid or comet impacting the Earth has been receiving more attention in recent years, due in part to the discovery of the Apophis asteroid, which was at one time projected to have a significant probability of impacting the Earth in the year 2029. Although a later analysis of the Apophis trajectory precluded this impact, the threat has brought a lot of attention to the dangers posed by asteroids. Many ideas have been put forward for mitigating such threats. This paper presents one such technique: the attachment of a long tether and ballast mass to change the orbit of an Earth-threatening asteroid or comet. Specifically, for this paper, a parametric study was conducted to determine to what degree the trajectory of an asteroid or comet could be altered by attaching a tether and ballast for various values of orbital semimajor axis and eccentricity and for various tether lengths and ballast mass sizes. The results show that a long tether and ballast mass could be effective for such a diversion. It was found that the technique was most effective using longer tethers and larger ballast masses on asteroids or comets with smaller, more eccentric, orbits.}, number={3}, journal={JOURNAL OF SPACECRAFT AND ROCKETS}, author={French, David B. and Mazzoleni, Andre P.}, year={2009}, pages={645–661} }
 @article{french_mazzoleni_2009, title={Near-Earth object threat mitigation using a tethered ballast mass}, volume={22}, DOI={10.1061/(ASCE)0893-1321(2009)22:4(460)}, abstractNote={The effects of the collision of a near-earth object (NEO) with the Earth could be catastrophic on a local, regional, or global scale depending on the size of the NEO. Therefore, there is considerable interest in determining ways to mitigate the threat posed by these objects. This paper presents a method using the attachment of a tether and ballast mass to alter the trajectory of a NEO on an Earth-intersecting orbit so that it avoids hitting the Earth. Furthermore, a parametric study of such a system is conducted over a wide range of parameters that describe the orbit and the system itself. For each set of parameters, a resulting “miss distance” due to the attachment of the tether and ballast mass is calculated. The results demonstrate that such a system could be used to protect the Earth from Earth-intersecting NEOs.}, number={4}, journal={Journal of Aerospace Engineering}, author={French, D. B. and Mazzoleni, A. P.}, year={2009}, pages={460–465} }
 @article{french_mazzoleni_2009, title={Parametric study of the diversion of a near Earth object on an Earth intersecting trajectory}, volume={65}, ISSN={["1879-2030"]}, DOI={10.1016/j.actaastro.2009.04.023}, abstractNote={To date, NASA's “Near Earth Object Program” has discovered over 5500 comets and asteroids on trajectories that bring them within “the neighborhood” of Earth's orbit. Nearly 1000 of these objects are classified as “potentially hazardous,” passing within 0.05 astronomical units of Earth's orbit. Discovery rates of such threatening bodies increase each year. Given this multitude of threats, in addition to evidence that the planet has absorbed many impacts over its history, it is reasonable to assume that another object will strike the Earth at some point in the future. Consequently, researchers have studied and proposed several mitigation techniques for such an occurrence. This study seeks to determine how effectively the attachment of a tether and ballast mass would divert the trajectory of such threatening objects. Specifically, the study analyzes the effects over time of such a system on objects of varying orbital semimajor axis and eccentricity, using various tether lengths and ballast masses. It was determined that the technique is most effective for NEOs with high eccentricity and small semimajor axis, and that system performance increases as tether length and ballast mass increase.}, number={11-12}, journal={ACTA ASTRONAUTICA}, author={French, David B. and Mazzoleni, Andre P.}, year={2009}, month={Dec}, pages={1698–1705} }
 @article{wilson_mazzoleni_dejarnette_antol_hajos_strickland_2008, title={Design, analysis, and testing of Mars Tumbleweed rover concepts}, volume={45}, ISSN={["1533-6794"]}, DOI={10.2514/1.31288}, abstractNote={A Mars Tumbleweed rover is a spherical, wind-driven, planetary rover. Compared with conventional rovers, a tumbleweed rover can travel farther faster and gain access to areas such as valleys and chasms that previously were inaccessible. This paper presents design, mathematical modeling, computer simulation, and testing of various tumbleweed rover concepts. In particular, we present wind-tunnel data indicating that a box-kite configuration represents a promising tumbleweed rover design, we show that a working box-kite–type tumbleweed can be constructed, and we show that center of mass variation shows promise as the basis of a tumbleweed rover navigation system.}, number={2}, journal={JOURNAL OF SPACECRAFT AND ROCKETS}, author={Wilson, Jamie L. and Mazzoleni, Andre P. and DeJarnette, Fred R. and Antol, Jeffrey and Hajos, Gregory A. and Strickland, Christopher V.}, year={2008}, pages={370–382} }
 @article{jung_chung_mazzoleni_2008, title={Dynamic stability of a semi-circular pipe conveying harmonically oscillating fluid}, volume={315}, ISSN={["0022-460X"]}, DOI={10.1016/j.jsv.2008.01.062}, abstractNote={The dynamic stability of a semi-circular pipe conveying harmonically oscillating fluid is investigated in this study. For analysis, harmonically oscillating flow is regarded as a parametrically excited system with time-varying coefficients. Considering the extensibility and nonlinearity of the semi-circular pipe, the equations of motion and the associated boundary conditions are obtained by using the extended Hamilton principle. Applying Floquet theory to the derived equations, the stability of the pipe is analyzed for variations of the amplitude and oscillating frequency of the fluid velocity. The effects of the mean value for the fluid velocity on the stability are also analyzed. It is found that the semi-circular pipe may become unstable when the fluctuation frequency approaches some multiples or sum of the out-of-plane natural frequencies. Furthermore, it is observed that the instability regions increase with the mean value of the velocity. The results obtained via the stability analysis are verified by time responses computed by using a direct time integration method.}, number={1-2}, journal={JOURNAL OF SOUND AND VIBRATION}, author={Jung, Duhan and Chung, Jintai and Mazzoleni, Andre}, year={2008}, month={Aug}, pages={100–117} }
 @article{hartl_mazzoleni_2008, title={Parametric study of spherical rovers crossing a valley}, volume={31}, ISSN={["0731-5090"]}, DOI={10.2514/1.33932}, abstractNote={T HE evidence ofwater onMars and the idea of using themoon as a staging ground for future planetary missions has increased interest in Martian and lunar exploration. Future missions will require the exploration of large areas on these surfaces because areas of scientific interest may be far away from the landing sites. Because of the inherent dangers with manned missions, rovers provide a viable option for future investigations of these regions. NASA currently employs wheeled rovers, including the Mars exploration rovers, to examine the Martian surface. These rovers are intricate and expensive, with limited ability to navigate rough terrain. This complicates gathering scientific data on Martian climate and geology and renders answering questions on the existence of water and life difficult. A vehicle capable of exploring large areas of terrain is the tumbleweed rover. A tumbleweed is a spherical (wind driven or selfpropelled) rover designed to provide superior mobility and greater accessibility on the surface of Mars and the moon. Compared with conventional wheeled rovers, a tumbleweed can cover vast distances faster and reach previously inaccessible areas of scientific interest, such as canyons and valleys. Because a tumbleweed is significantly less expensive than traditional rovers, multiple tumbleweeds can be deployed across the Martian or lunar surface for scientific surveys. The tumbleweed’s design is also well suited for polar missions because the rover can seek out water sources beneath a surface desert or an ice sheet, a task that cannot be done accurately from orbit. For these reasons, parametric studies describing and predicting a tumbleweed’s motion across the Martian or lunar terrain is valuable. The tumbleweed rover is based on concepts going back to the 1970s, where Jacques Blamont of the National Center for Space Studies developed the notion for wind-driven rovers. The concept has been pursued by several investigators at the NASA Langley Research Center (LaRC) and at the Jet Propulsion Laboratory (JPL). LaRC is focusing on concepts based on lightweight deployable structures, while JPL is focusing on inflatable concepts based on airbag landing technology. Other organizations, including Texas Technical University (TTU), North Carolina State University (NCSU), and the Swiss Federal Institute of Technology, are also examining wind-driven rover concepts. Research into the tumbleweed rover’s dynamics, however, is in its early stages. Feasibility studies on wind-driven mobility on the surface of Mars have been examined [1–8] and other studies have presented dynamic models for particular tumbleweed concepts [9– 14]. Several areas have been identified where the existing research can be expanded. Particularly, a numerical simulation model predicting a tumbleweed’s motion for arbitrary terrains is needed. Also required are parametric studies describing the tumbleweed’s behaviors on these terrains, which include flat planes, hills, ravines, and valleys. This paper presents parametric studies of a tumbleweed (or spherical) rover as it moves across a valley. The model used covers the rover’s bouncing, sliding, and rolling behaviors and its transitions between different terrain types. We present studies of the rover’s motion for various sets of parameters and initial conditions. Theses parametric studies will provide an understanding of the range of tumbleweed design parameters essential for mobility over shallow and deep valleys on Mars.}, number={3}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Hartl, Alexandre E. and Mazzoleni, Andre P.}, year={2008}, pages={775–779} }
 @article{padgett_mazzoleni_2007, title={Analysis and design for no-spin tethered satellite retrieval}, volume={30}, ISSN={["0731-5090"]}, DOI={10.2514/1.25390}, abstractNote={T ETHERED satellites are composed of two or more orbiting bodies connected by light, flexible members known as tethers. The study of tethered satellites began with Tsilokovsky in 1895 and was taken up by Artsutanov in the 1950s [1]. Since that time a number of researchers have studied aspects of the application of tethered satellite systems including the dynamics of tethered satellites and the architecture of tethered satellite missions [1–9]. Tethered satellites are of interest both because of the physical and mathematical problems they present and because of their many practical uses. Tethered satellite systems have been identified as candidates for novel atmospheric probes, interferometers, magnetometers, and gravity gradiometers among other devices [10–14]. Some far term applications of tethered satellites include the tethered artificial gravity (TAG) system and the momentum exchange and electrodynamic reboost (MXER) system. The TAG system is a device capable of imparting an artificial gravitational force to bodies on orbit [15], whereas the MXER system is a momentum exchange device designed to boost payloads into higher orbits without the use of chemical propellants [16]. Numerous other uses for tethered satellites in space are detailed in [17]. During the course of a tethered satellite mission, it may be necessary to shorten the overall length of the tether. The purpose of such a retrieval could be to facilitate the repair or servicing of the tethered satellite assembly, to reduce the profile of the orbital debris created by a satellite at the end of its useful life, or simply to alter the dynamical behavior of the tethered satellite system. We will show that in general, such a length contraction causes the tethered satellite system to enter a spin with respect to the orbital reference frame. In many of the instances described above, the reason for retrieving a tethered satellite system necessitates that the system not spin with respect to the orbital reference frame; such a maneuver could be achieved through the use of a sophisticated angular velocity control system. However, by exploiting the dynamics of a tethered satellite system, it is possible to reduce the length of the system without causing the system to enter a spin. Analysis of the equations of motionwill reveal that under an exponential length control law, there exist initial tethered satellite states for which the tethered satellite system can be retrieved and remain stationary with respect to the orbital reference frame during the course of the retrieval maneuver. These points, which correspond to the equilibria of the system, will be identified and classified. We will describe the motion of a simplified tethered satellite system undergoing retrieval in the neighborhood of these equilibrium points.}, number={5}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Padgett, David A. and Mazzoleni, Andre P.}, year={2007}, pages={1516–1519} }
 @article{padgett_mazzoleni_2007, title={Nullcline analysis as an analytical tethered satellite mission design tool}, volume={30}, ISSN={["0731-5090"]}, DOI={10.2514/1.20946}, abstractNote={Tethered satellite systems have been proposed for many space mission applications due to the useful dynamics that can be generated with relatively low fuel expenditures. Increasing interest in tethered satellite systems necessitates a fundamental understanding of the dynamics of such systems. An analytic method of qualitatively describing the possible dynamics of a tethered satellite system is presented. This analysis is centered on the study of the sets of states for which at least one of the nondimensional time derivatives of the state variables is zero. These sets are known as the nullclines of a system, and they bound regions of the phase plane in which tethered satellite behavior is similar. The qualitative analysis of the nullclines provides an explanation for, and suggests the controllability of, many types of tethered satellite behavior. For the purposes of this paper, a tethered artificial gravity satellite system is used as a canonical tethered system and the results derived are applied to this system. The utility of the described analytical method is demonstrated by using the method to characterize two different tethered satellite missions.}, number={3}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Padgett, David A. and Mazzoleni, Andre P.}, year={2007}, pages={741–752} }
 @article{mantri_mazzoleni_padgett_2007, title={Parametric study of deployment of tethered satellite systems}, volume={44}, ISSN={["1533-6794"]}, DOI={10.2514/1.22955}, abstractNote={Deployment of a tethered satellite system is the process of separating the two end bodies by spooling out the tether connecting them. In this paper, we describe a 3-Dmodel of a tethered satellite system undergoing deployment. From the equations of motion obtained using the 3-D model, we identify five system parameters that affect the length to which a tethered satellite systemwill deploy. The equations ofmotion describing the tether deployment are solved for a given range of each of the parameters to determine the effect of each of the parameters on the level of deployment reached. The equations are then nondimensionalized; nondimensionalization reduces the number of system parameters fromfive to two and increases the generality of the equations ofmotion. The nondimensional equations of motion are solved numerically, and the results are presented in charts andplots that can be used bymission designers to predict the final deployed length under given operating conditions. Two case studies are presented to demonstrate the utility of these tools.}, number={2}, journal={JOURNAL OF SPACECRAFT AND ROCKETS}, author={Mantri, Parag and Mazzoleni, Andre P. and Padgett, David A.}, year={2007}, pages={412–424} }
 @book{coffey_mazzoleni_luu_glover_2005, place={San Diego, California}, series={Advances in the astronautical sciences}, title={Spaceflight mechanics 2004 : proceedings of the 14th AAS/AIAA Space flight mechanics meeting held 8-12 February 2004, Maui, Hawaii}, ISBN={9780877035152}, ISSN={1081-6003}, publisher={Univelt for the American Astronautical Society}, author={Coffey, S.L. and Mazzoleni, A.P. and Luu, K.K. and Glover, R.A.}, year={2005}, month={Mar}, collection={Advances in the astronautical sciences} }
 @article{miller_gray_mazzoleni_2001, title={Nonlinear Spacecraft Dynamics with a Flexible Appendage, Damping, and Moving Internal Submasses}, volume={24}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/2.4752}, DOI={10.2514/2.4752}, abstractNote={We study the attitude dynamics of a single-body spacecraft that is perturbed by the motion of small oscillating submasses, a small e exible appendage constrained to undergo only torsional vibration, and a rotor immersed in a viscous e uid. We are interested in the chaotic dynamics that can occur for certain sets of the physical parameter values of the spacecraft when energy dissipation acts to drive the body from minor to major axis spin. Energy dissipation, which is present in all spacecraft systems and is the mechanism that drives the minor to major axis transition, is implemented via the rotor. We not only obtain an analytical test for chaos in terms of satellite parametersusing Melnikov’ s method, but wealso use extensivenumericalsimulation to check the rangeof validity of the Melnikov result.}, number={3}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Miller, Andrew J. and Gray, Gary L. and Mazzoleni, Andre P.}, year={2001}, month={May}, pages={605–615} }
 @article{gray_mazzoleni_campbell_1998, title={Analytical Criterion for Chaotic Dynamics in Flexible Satellites with Nonlinear Controller Damping}, volume={21}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/2.4294}, DOI={10.2514/2.4294}, abstractNote={In this work, we study the attitude dynamics of a single body spacecraft that is perturbed by the motion of a small flexible appendage constrained to undergo only torsional vibration. In particular, we are interested in the chaotic dynamics that can occur for certain sets of the physical parameter values of the spacecraft when energy dissipation acts to drive the body from minor to major axis spin. Energy dissipation, which is present in all spacecraft systems and is the mechanism that drives the minor to major axis transition, is implemented by a quantitative energy sink that is modeled with a nonlinear controller. We obtain an analytical test for chaos in terms of satellite parameters by Melnikov's method. This analytical criterion provides a useful design tool to spacecraft engineers who are concerned with avoiding potentially problematic chaotic dynamics in their systems. In addition, we show that a spacecraft with a control system designed to provide energy dissipation can exhibit chaos because of the inherent flexibility of its components.}, number={4}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Gray, Gary L. and Mazzoleni, Andre P. and Campbell, David R., III}, year={1998}, month={Jul}, pages={558–565} }
 @article{mazzoleni_hall_stabb_1996, title={Double averaging approach to the study of spinup dynamics of flexible satellites}, volume={19}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/3.21579}, DOI={10.2514/3.21579}, abstractNote={We study the dynamics of a class of flexible dual-spin satellites in which the rotor is spun up by a small constant torque T applied by the platform. We use a previously published zero torque solution that was obtained using the Krylov-Bogoliubov-Mitropolski averaging method. A second application of averaging developed herein leads to a reduction of the equations of motion from a sixth-order system to a single first-order equation describing the slow evolution of energy as a function of the axial angular momentum of the rotor. The geometrical interpretation of this reduction involves projecting solutions onto a certain bifurcation diagram. Numerical solutions of the averaged equation agree with numerical solutions to the full sixth-order system and show that the flexible spacecraft behaves essentially the same as its rigid counterpart during the spinup maneuver.}, number={1}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Mazzoleni, Andre P. and Hall, Christopher D. and Stabb, Mark C.}, year={1996}, month={Jan}, pages={54–59} }
 @article{mazzoleni_dobson_1995, title={Closest bifurcation analysis and robust stability design of flexible satellites}, volume={18}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/3.21388}, DOI={10.2514/3.21388}, abstractNote={We consider the design of a satellite to ensure robust stability in a high-dimensional parameter space. Starting with a given nominal design that is stable, we compute instabilities that are locally closest to the nominal design in the design parameter space. If these worst-case instabilities are too close, we compute a design that is sufficiently far from the worst-case instabilities and hence sufficiently robust. The methods are based on computations from bifurcation theory and are considerably simplified by our assumption of a Hamiltonian satellite, which includes spin-stabilized satellites, dual-spin-stabilized satellites, and gravity-gradient-stabilized satellites. The Hamiltonian assumption is then relaxed to allow the inclusion of damping terms. We illustrate the computations by ensuring the robust stability of a flexible dual-spin satellite with six design parameters.}, number={2}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Mazzoleni, Andre P. and Dobson, Ian}, year={1995}, month={Mar}, pages={333–339} }
 @article{mazzoleni_schlack_1995, title={Full Field Stability Analysis of Guy-Wired Satellites}, volume={43}, number={1}, journal={Journal of the Astronautical Sciences}, author={Mazzoleni, A.P. and Schlack, A.L.}, year={1995}, month={Jan}, pages={47–57} }
 @article{mazzoleni_dobson_1995, title={Instability tests, Lyapunov's direct method, and exact stability boundaries for flexible satellites}, volume={18}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/3.21405}, DOI={10.2514/3.21405}, abstractNote={Simple tests are developed to determine instability regions in the parameter space of flexible satellites. These tests are used in conjunction with Lyapunov's direct method to obtain exact stability boundaries in parameter space in cases where Lyapunov methods give only sufficient conditions for stability. In the case of Hamiltonian systems, the tests reduce to checking the sign of the determinant of the Hessian of the Hamiltonian at a single point. The Hamiltonian assumption can be relaxed to allow the inclusion of damping terms provided these terms have no linear dependence on position. Previous studies use complete or pervasive damping assumptions to obtain exact stability boundaries, whereas the proposed methods work for no damping or the damping described earlier. Examples illustrate the usefulness of the tests.}, number={3}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Mazzoleni, Andre P. and Dobson, Ian}, year={1995}, month={May}, pages={426–432} }
 @article{mazzoleni_shen_1995, title={The Product of Chord Lengths of a Circle}, volume={68}, ISSN={0025-570X}, url={http://dx.doi.org/10.2307/2691381}, DOI={10.2307/2691381}, number={1}, journal={Mathematics Magazine}, publisher={Informa UK Limited}, author={Mazzoleni, Andre P. and Shen, Samuel Shan-Pu}, year={1995}, month={Feb}, pages={59} }
 @article{mazzoleni_schlack_1994, title={Comparative stability study illustrating advantages of guy-wire constraints for flexible satellites}, volume={17}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/3.21324}, DOI={10.2514/3.21324}, abstractNote={Conclusion We have briefly reviewed four ways of modeling friction in bearings, namely, the Coulomb model, Dahl model, friction circle model, and viscous friction model. Although only Coulomb friction requires the consideration of a two-degree-of-freedom model, it is clear that this gives a richness of detail on stick-slip motion at the contact point that is not given by the other friction models, even though the gross motion of the rotor is reproduced equally well by all four models. Coulomb friction requires three sets of differential equations of motion corresponding to a single contact point, one for sliding, one for sticking, and a third for the transition from sticking to slipping. When friction must be considered at many bearings in a system, a simpler friction model may be preferred.}, number={5}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Mazzoleni, A. P. and Schlack, A. L.}, year={1994}, month={Sep}, pages={1139–1141} }
 @article{mazzoleni_schlack_1991, title={Gravity gradient stability of satellites with guy-wire constrained appendages}, volume={14}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/3.20722}, DOI={10.2514/3.20722}, number={4}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Mazzoleni, Andre P. and Schlack, A. L.}, year={1991}, month={Jul}, pages={855–857} }
 @article{mazzoleni_sisken_kahler_1986, title={Conductivity Values of Tissue Culture Medium from 20°C to 40°C}, volume={7}, DOI={10.1002/bem.2250070111}, abstractNote={Abstract}, number={1}, journal={Bioelectromagnetics : journal of the Bioelectromagnetic Society}, author={Mazzoleni, A.P. and Sisken, B.F. and Kahler, R.L.}, year={1986}, pages={95–99} }