### ASA 124th Meeting New Orleans 1992 October

## 5aPAa6. Radial wave thermoacoustic engines.

**W. Patrick Arnott
**

**
**
*Atmospheric Sci. Ctr., Desert Res. Inst., P.O. Box 60220, Sage Bldg.,
Reno, NV 89506-0220
*

*
*
Thermoacoustic heat engines are used to produce sound from heat and to
transport heat using sound. Most previous work has concentrated on engines in
plane-wave resonators. This paper is about the analysis of engines in radial
mode cylindrical resonators. Impedance and pressure translation equations are
shown for open sections of the resonator and for heat exchangers. Coupled
first-order differential equations are given for pressure and impedance in the
temperature-gradient-supporting engine sections. These quantities are used in
the computation of energy transfer, and allow for complete analysis of engines
with a variety of boundary conditions. Analysis is compared for engines in
cylindrical and plane-wave resonators. Previous work in plane-wave resonators
has shown that the quality factor Q increases to (infinity) as the temperature
gradient across the engine becomes sufficiently large. An application of the
derived theory is Q and dQ/(denvironment) control of a cylindrical resonator in
the design of thermoacoustically enhanced photoacoustic spectrometers that are
potentially useful for measuring light absorption by atmospheric aerosols.