The thermal interaction between a stack and the acoustically driven working fluid is investigated by measuring the temperature fields.  Temperature fields are measured at the edges, at different locations on the solid stack plate, and at the neighboring working fluid. This information is necessary for the optimization of the performances of practical thermoacoustic engines. The temperature measurements at the extremities and at the neighboring gas show axial heat transfer at the stack extremities, as opposed to the hypothesis of a perfectly isolated stack used in the linear thermoacoustic theory. Four different mechanisms of heat transfer are identified at the stack extremities in the present study. For the selected operating conditions, temperature measurements along the stack also reveal a linear behavior along the stack and the corresponding gas residing near the stacks.

Keywords: Thermoacoustic heat pump, Thermal field measurement, linear theory