@article{anand_gould_2021, title={Analysis of a Symmetrical Ferrofluid Sloshing Vibration Energy Harvester}, volume={6}, ISSN={["2311-5521"]}, DOI={10.3390/fluids6080295}, abstractNote={Ferrofluid sloshing vibration energy harvesters use ferrofluid sloshing movement as a moving magnet between a fixed coil to induce current and, in turn, harvest energy from external excitations. A symmetric ferrofluid sloshing vibration energy harvester configuration is introduced in this study which utilizes four external, symmetrically placed, permanent magnets to magnetize a ferrofluid inside a tank. An external sinusoidal excitation of amplitude 1 m/s2 is imparted, and the whole system is studied numerically using a level-set method to track the sharp interface between ferrofluid and air. The system is studied for two significant length scales of 0.1 m and 0.05 m while varying the four external magnets’ polarity arrangements. All of the system configuration dimensions are parametrized with the length scale to keep the system configuration invariant with the length scale. Finally, a frequency sweep is performed, encompassing the structure’s first modal frequency and impedance matching to obtain the system’s energy harvesting characteristics.}, number={8}, journal={FLUIDS}, author={Anand, Nadish and Gould, Richard}, year={2021}, month={Aug} }
@article{jasper_anand_2019, title={A generalized variational approach for predicting contact angles of sessile nano-droplets on both flat and curved surfaces}, volume={281}, ISSN={["1873-3166"]}, DOI={10.1016/j.molliq.2019.02.039}, abstractNote={Abstract Derivations of Young's equation have traditionally neglected the Laplace pressure and its influence on the curvature of sessile droplets under thermodynamic equilibrium. Omission of the Laplace pressure results in overestimating the line tension by several orders of magnitude and contributes to significant errors in predicting the contact angle for droplet volumes ranging from micro-liters to atto-liters. This paper addresses this issue and offers a correct inclusion of VdP as a virtual work term in the free energy variation at the liquid-vapor boundary for both flat and curved surfaces. While the Laplace pressure is constant at the liquid-vapor interface as a condition of equilibrium, the variation of the Laplace pressure is not zero, as it influences both the shape (spherical cap) and contact angle of sessile droplets. Inclusion of this term leads naturally to a definition of the line tension as a volume dependent term, and more importantly to a correct prediction in both sign and magnitude of the line tension value. The inclusion of VdP work predicts a cubic relationship between the cosine of the contact angle and droplet line radius. This new model extends existing theories on the behavior of nanosized droplets and its predictions exhibit quantitative agreement with experimental results for nonane, dodecane, fullerene, and glycerol trioleate over a range of 15 orders of magnitude in droplet volume. Finally, we also theorize the existence of two different equilibrium contact angles at lower droplet volumes. These two values diverge with the inverse line radius.}, journal={JOURNAL OF MOLECULAR LIQUIDS}, author={Jasper, Warren J. and Anand, Nadish}, year={2019}, month={May}, pages={196–203} }
@inproceedings{anand_gould_2017, title={A convenient low order thermal model for heat transfer characteristics of single floored low-rise residential buildings}, DOI={10.1115/imece2016-65254}, abstractNote={A low order thermal model is introduced to determine the thermal characteristics of a Low-Rise Residential (LRR) building and then predict the energy usage by its Heating Ventilation & Air Conditioning (HVAC) system according to future weather conditions. The LRR buildings are treated as a simple lump and the model is derived using the lumped capacitance model for transient heat transfer from bodies. Most contemporary HVAC systems have a thermostat control, which has an offset temperature, and user defined set point temperatures, which defines when the HVAC system will switch on and off. The aim is to predict, with minimal error, the inside air temperature, which is used to determine the switching on and off, of the HVAC system. To validate this lumped capacitance model we have used the EnergyPlus simulation engine, which simulates the thermal behavior of buildings with considerable accuracy. We have predicted using the low order model the inside air temperature of a single family house located in three different climate zones (Detroit, Raleigh & Austin) and different orientations for summer and winter seasons. The prediction error between the model and EnergyPlus is less than 10% for almost all the cases with the exception of Austin in summer. Possible factors responsible for error in prediction are also noted in this work, paving way for future research.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2016, vol. 6b}, author={Anand, N. and Gould, R. D.}, year={2017} }