ASA 126th Meeting Denver 1993 October 4-8

2aPAa10. Dynamics of a dual-driver acoustic resonator and control system used in a thermoacoustic refrigerator.

D. Felipe Gaitan Steven L. Garrett

Naval Postgraduate School, Monterey, CA 93943

Until the development of the Thermoacoustic life sciences refrigerator (TALSR) [S. L. Garrett et al., J. Acoust. Soc. Am. 93, 2364 (1993)], all previous thermoacoustic refrigerators employed only a single electrodynamic driver. Due to the acoustic power requirements for TALSR, a dual-driver, half-wavelength engine was designed. This introduces additional complications for the resonance frequency control and tracking circuitry since each driver constitutes a driven simple harmonic oscillator and the two drivers, both of which have an associated microphone and accelerometer, are coupled by an acoustically resonant system. A computer model of the three strongly interacting resonant systems will be described along with a series of experimental measurements that explored a variety of operating conditions. [Work supported by NASA---Life Sciences Division and the Naval Postgraduate School Direct Funded Research Program.]