### ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

## 5pPAb4. The effect of phase of the acoustic wave on the efficiency of
thermoacoustic refrigerators.

**James Brewster
**

**
Richard Raspet
**

**
**
*Dept. of Phys. and Astron., Natl. Ctr. for Phys. Acoust., Univ. of
Mississippi, University, MS 38677
*

*
*
An analytic approach to the study of thermoacoustics and application of
this technique to the optimization of a refrigerator driven by an arbitrary
acoustic wave will be presented. It will be shown that although a standing wave
driven cooler has close to optimum efficiency, the efficiency can be improved
by the addition of a traveling component to the wave field flowing in the
direction of negative temperature gradient. The value of the acoustic impedance
in the gas bordering the cold end of the stack is fixed to an arbitrary value.
Application of the continuity of pressure and velocity is combined with the
wave equation to yield the value of the pressure wave function and its first
two derivatives at the cold end of the stack. Knowledge of these allows the
direct calculation of the efficiency of refrigeration and the second derivative
of the temperature distribution. [Work supported in part by Office of Naval
Research.]