Electronic Thesis and Dissertation Repository


Master of Engineering Science


Mechanical and Materials Engineering


Dr. Anthony Straatman


The motivation of this thesis is the development of simple microscopic-scale model (representative elemental volume; REV) that can be used to conduct flow and heat transfer simulations from which closure coefficients can be established for the volume-averaged transport equations for porous media (packed bed). The thesis provides a brief introduction to the computational technique adopted for the geometric generation of the REV (YADE), followed by a parametric study undertaken to reveal the minimum number of particles inside the REV that are required to mimic the appropriate physics. Additional analysis was conducted with the goal of determining the influence of deviation in particle diameter. A wide range of particle temperatures was considered for analyzing the convective heat transfer and hydrodynamic behavior such the influence of property variation on temperature could also be studied.

The key research output is a detailed comparison of the results related to the hydrodynamics and heat transfer closures produced by an idealized, YADE-generated model against a three-dimensional, digitized model of packed sand. It is shown that the YADE model gives results that are in very good agreement with the digitized packed-sand model in the range of Reynolds numbers considered. The YADE model results were then compared with experimental findings and it was found that while the trends in convective heat transfer were well-predicted, there was a difference in the magnitude of the convective coefficients predicted and measured in previous experiments.