@article{bhaskaran_ro_park_ramakrishnan_2017, title={Analysis of a Novel Technique for Temperature Rise Abatement in Liquid Piston Compressors-External Gas Injection}, volume={9}, ISSN={["1948-5093"]}, DOI={10.1115/1.4035969}, abstractNote={This paper analyses a novel heat transfer enhancement technique that can be used in compressors to limit the temperature rise during compression. This technique is based on the injection of external high-pressure gas into the chamber during the compression process. The impact of different factors on the effectiveness of this technique has been studied using experimental and computational methods. In the first set of trials, the location and angle of injection of the external air was varied. It was observed that the heat transfer coefficient governing the heat transfer rate from the chamber varied greatly with change in location and angle of injection. In the second set of experiments, the source pressure of the injected gas was varied from 100.66 kPa to 551.58 kPa. It was observed that the temperature rise of air in the chamber was reduced with an increase in source pressure. Additionally, the increase in chamber pressure was steeper in the higher source pressure cases. In the third set of experiments, the injection profile of the injected gas was varied. This parameter did not greatly impact the effectiveness of external gas injection. In the last set of experiments, the time of initiation of injection was varied. Earlier injection had a positive impact on reducing the temperature rise in the chamber. However, the pressure in the chamber was seen to increase more rapidly in the runs with early injection. Considering that these factors could have a positive/negative impact on the temperature and pressure in the chamber (work required for compression), it may be required to optimize the injection of external high-pressure gas depending on the application.}, number={2}, journal={JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS}, author={Bhaskaran, Hari Subramaniam and Ro, Paul and Park, Joong-Kyoo and Ramakrishnan, Kishore Ranganath}, year={2017}, month={Jun} }
 @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{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{park_ro_2013, title={Noncontact Manipulation of Light Objects Based on Parameter Modulations of Acoustic Pressure Nodes}, volume={135}, ISSN={["1528-8927"]}, DOI={10.1115/1.4023816}, abstractNote={An investigation of noncontact manipulation techniques based on acoustic levitation was undertaken in air. The standing wave acoustic levitation (SWAL) was observed when standing waves trap small objects at pressure nodes. In this paper, two ultrasonic bolt-clamped Langevin type transducers (BLTs) generating traveling waves by modulating parameters of the two traveling waves were used to manipulate a trapped object. Frequency, amplitude, and phase modulations of the two actuators were exploited. From simulation and experiments, the phase modulation was prominent among other methods due to its long range and smooth operation. It is also found that angles between two actuators affect the trajectory of the trapped object during the parameter modulations. Sinusoidal and elliptic paths of the object were observed experimentally through a combination of parameters at certain tilt angles.}, number={3}, journal={JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME}, author={Park, Joong-kyoo and Ro, Paul I.}, year={2013}, month={Jun} }
 @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} }