RADIAL WAVE THERMOACOUSTIC ENGINES - THEORY AND EXAMPLES FOR REFRIGERATORS AND HIGH-GAIN NARROW-BANDWIDTH PHOTOACOUSTIC SPECTROMETERS

A theoretical analysis of radial wave thermoacoustic engines in cylind rical resonators is developed. impedance and pressure translation equa tions are presented for open sections of the resonator and for heat ex changers. Coupled first-order differential equations are given for pre ssure and impedance in the temperature gradient supporting engine sect ion (stack). These quantities are used to calculate heat and work flow s and to predict engine performance. Theory and design of a variable q uality factor resonator for enhanced photoacoustic spectroscopy are pr esented. The short stack approximation is developed for the radial geo metry and is used along with plane-wave equations to compare refrigera tor performance for these two geometries. Results of the comparison ar e that engines in the plane-wave geometry are better overall refrigera tors when maximizing the coefficient of performance and cooling capaci ty together. (C) 1996 Acoustical Society of America.