Comparison of a pin stack to a conventional stack in a thermoacoustic prime mover

Abstract

This thesis compares the pin stack with a conventional rolled stack for a thermoacoustic prime mover. A pin stack is a new geometry for stacks used in thermoacoustic engines consisting of a lattice of small wires which are spaced about a thermal penetration depth apart. Computer simulations were conducted on a variety of pin stack geometries and operating parameters. Results indicate that the modeling program, DeltaE, agrees with the experimental results for conventional stacks, that the pin stack decreases viscous energy losses, and greatly increases the efficiency of the thermoacoustic engine over a large range of mean pressures. The pin stack performance was found to be more sensitive than the conventional stack to changes in thermal and viscous penetration depths of the fluid.