Measurements of the evolution of the temperature profile in a parallel plate stack

Results of preliminary measurements on the evolution of the temperature profile in a parallel plate stack were previously reported [Atchley et al., J. Acoust. Soc. Am. 99, 2559(A) (1996)]. Those measurements were made on a 6.89‐cm‐long, five plate stainless‐steel stack, with a 2.46‐mm plate separation and located at kx=3.46 within a 2.75‐m‐long standing resonator. The resonator was at atmospheric pressure and driven at a frequency of approximately 93 Hz. Those measurements showed that the steady‐state temperature gradient was approximately linear along the plate for drive ratios below approximately 2%. For higher drive ratios, the gradient was no longer linear. More complete measurements are reported using various gases at different mean pressures. In particular, the plate is instrumented with several thermocouples within an acoustic displacement amplitude of the edges of the plate. In addition, thermocouples are placed in the gap between the plates. The purpose of this work is to investigate transient effects in thermoacoustic devices and to provide data to test nonlinear, time‐dependent models of thermoacoustics.