Experimental Study of a Standing-Wave Transcritical Thermoacoustic Device

A prototype transcritical thermoacoustic engine has been constructed and tested, yielding thermoacoustic results. Three different thermoacoustic “stack” designs have been evaluated in the present study. All three show damped acoustic oscillations as a temperature gradient is produced along the stack and a non-linear perturbation is induced. Spontaneously instabilities at much lower frequency were observed in the device with one of the “stacks”. These instabilities grew to a limit cycle amplitude that was maintained until heat was removed. Data are presented for both types of instabilities over a range of operating conditions