Tuesday, April 23, 2002

(Dr. David McDowell, advisor)

"Thermal Properties of Linear Cellular Alloys"

__Abstract__

Linear Cellular Alloys (LCAs) are metallic honeycomb materials which can be extruded with varying cell structures. The process used to manufacture these materials involves the use of oxide powders and organic binders. The resulting paste can be extruded and then reduced. The cross-sections of these short prismatic beams are honeycomb-like, with cells that run the length of the structure.

*Thermal Properties of Linear Cellular Alloys* explores the heat transfer
capability of the LCAs. Thermal diffusivity experiments are performed to determine
the thermal properties of in situ cell wall materials. A finite difference code
is created, as a design tool, to predict the convective heat sink characteristics
of the LCA under thermal loading. The thermal properties obtained from the experiments
are used in the finite difference code to enhance its prediction capabilities.
The finite difference code incorporates hydrodynamically and thermally developing
flow for square cell geometries, and a simple example involving optimized rectangular
cell geometries is pursued as a proof of concept. The analytical solution to
the isothermal case is used as an upper bound to benchmark the code. Experiments
that evaluate the LCA performance as a heat sink also provide validation of
the finite difference code. The pressure drop through the LCA is measured and
compared to analytical results. The thermal performance of LCAs is compared
that of stochastic metal foams.