Microtomography-Based Simulation of Transport through Open-Cell Metal Foams

Abstract

Important heat transfer parameters of aluminum foams of varying pore sizes are investigated through CT-scanning at 20 micron resolution. Small sub-samples from the resulting images are processed to generate feature-preserving, finite-volume meshes of high quality. All three foam samples exhibit similar volumetric porosity (in the range ∼91–93%), and thereby a similar thermal conductivity. Effective tortuosity for conduction along the coordinate directions is also calculated. Permeability simulations in the Darcy flow regime with air and water show that the foam permeability is isotropic and is of the order of 10⁻⁷ m². The convective heat transfer results computed for this range of Reynolds numbers exhibit a dependence on the linear porosity, even though the corresponding volumetric porosity is the same for all the samples considered.

The authors acknowledge the assistance of Dr. Eric Nauman of Purdue University for kindly scanning the foam samples. Support for this work from industry members of Cooling Technologies Research Center, an NSF Industry/University Cooperative Research Center, is also gratefully acknowledged.