@article{watkins_chilamkurti_gould_2020, title={Analytic Modeling of Heat Transfer to Vertical Dense Granular Flows}, volume={142}, ISSN={["1528-8943"]}, DOI={10.1115/1.4045311}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME}, author={Watkins, Megan F. and Chilamkurti, Yesaswi N. and Gould, Richard D.}, year={2020}, month={Feb} }
 @article{chilamkurti_gould_2020, title={CFD-DEM and PR-DNS studies of low-temperature densely packed beds}, volume={159}, ISSN={["1879-2189"]}, DOI={10.1016/j.ijheatmasstransfer.2020.120056}, abstractNote={Over the past few decades, granular media is gaining attention as a viable option for heat transfer fluids (HTFs). Several research efforts are studying the use of particle-based heat transfer fluids in a wide variety of applications. With this motivation, the current work focusses on analyzing the different heat transfer mechanisms in low-temperature mono-sized densely packed granular media. To study the heat transfer behavior of granular media at different scales, the current work employs a two-way coupled computational strategy. The motion of particles is solved using the Discrete Element Method (DEM) and the interstitial air is solved using a Finite-Volume (CFD) approach. The Open-Source library CFDEM Coupling® is used in the current study to join the Finite Volume PISO solver of OpenFOAM® and the DEM solver of LIGGGHTS®. Typically, particle-particle contact conduction and particle-air convection are the most popular closure models. But recent research identified a different heat transfer phenomenon in packed beds that cannot be identified by conduction or convection models. Though closure models were developed to implement this on a CFD-DEM framework, they did not capture the effect of intra-particulate thermal gradients on this phenomenon. Hence the current work also employs Particle-Resolved Direct Numerical Simulations (PR-DNS) to gain valuable insights allowing for the modification of existing models. A new closure model is then proposed here and is implemented in the CFD-DEM framework. This model provides key insights into the different heat transfer mechanism of packed beds.}, journal={INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER}, author={Chilamkurti, Yesaswi N. and Gould, Richard D.}, year={2020}, month={Oct} }
 @inproceedings{chilamkurti_gould_2017, title={Characterizing particle-wall contact behavior and fluctuations in gravity-driven dense granular flows in cylindrical tubes using dem}, booktitle={Proceedings of the ASME Power Conference Joint with ICOPE-17, 2017, vol 2}, author={Chilamkurti, Y. N. and Gould, R. D.}, year={2017} }
 @inproceedings{chilamkurti_gould_2016, title={Discrete element studies of gravity-driven dense granular flows in vertical cylindrical tubes}, DOI={10.1115/power2016-59159}, abstractNote={The current paper focusses on the characterization of gravity-driven dry granular flows in cylindrical tubes. With a motive of using dense particulate media as heat transfer fluids (HTF), the main focus was to address the characteristics of flow regimes with a packing fraction of ∼60%. In a previous work [1], experimental and computational studies were conducted to understand the effects of different geometrical parameters on the flow physics. The current paper is an extension of that work to gain more insights into the granular flow physics. The three-dimensional computer simulations were conducted by implementing the Discrete Element Method (DEM) for the Lagrangian modelling of particles. Hertz-Mindilin models were used for the soft-particle formulations of inter-particulate contacts. Simulations were conducted to examine the particulate velocities and flow rates to understand the rheology in the dense flow regime. Past studies suggested the existence of a Gaussian mean velocity profile for dense gravity-driven granular flows. These observations were further analyzed by studying the influence of geometrical parameters on the same. The current work thus focusses on studying the rheology of dense granular flows and obtaining a better understanding of the velocity profiles, the wall friction characteristics, and the particle-wall contact behavior.}, booktitle={Proceedings of the ASME Power Conference, 2016}, author={Chilamkurti, Y. N. and Gould, R. D.}, year={2016} }
 @inproceedings{chilamkurti_gould_2016, title={Experimental and computational studies of gravity-driven dense granular flows}, DOI={10.1115/imece2015-50762}, abstractNote={The current paper focusses on the characterization of gravity-driven dry granular flows in cylindrical tubes. With a motive of using dense particulate media as heat transfer fluids (HTF), the study was primarily focused to address the characteristics of flow regimes with a packing fraction of ∼60%. Experiments were conducted to understand the effects of different flow parameters, including: tube radius, tube inclination, tube length and exit diameter. These studies were conducted on two types of spherical particles — glass and ceramic — with mean diameters of 150 μm and 300 μm respectively. The experimental data was correlated with the semi-empirical equation based on Beverloo’s law. In addition, the same flow configuration was studied through three-dimensional computer simulations by implementing the Discrete Element Method for the Lagrangian modelling of particles. A soft-particle formulation was used with Hertz-Mindilin contact models to resolve the interaction forces between particles. The simulation results were used to examine the velocity, shear rate and packing fraction profiles to study the detailed flow dynamics. Curve-fits were developed for the mean velocity profiles which could be used in developing hydrodynamic analogies for granular flows. The current work thus identifies the basic features of gravity driven dense granular flows that could form a basis for defining their rheology.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2015, vol 7a}, author={Chilamkurti, Y. N. and Gould, R. D.}, year={2016} }