ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

1aPA7. A thermoacoustic pin stack.

F. Scott Nessler

Robert M. Keolian

Dept. of Phys., Code PH/Kn, Naval Postgraduate School, Monterey, CA 93943

A comparison of the pin stack geometry with a conventional rolled geometry for thermoacoustic engines is being made in a modular prime mover test rig. By decreasing viscous energy losses, it is hoped that the pin stack will improve the efficiencies of thermoacoustic engines. The stack will consist of over two thousand 75-(mu)m wires, separated by 750 (mu)m, in a hexagonal lattice hand sewn between two finned copper heat exchangers. A temperature gradient will be applied to the stack and the neon working fluid by holding one exchanger at 300 K and the other at 77 K. A small acoustic driver in the rig will allow us to measure the quality factor Q below onset as a function of the neon pressure. [Work supported by ONR.]