Experiments with a flow-through thermoacoustic refrigerator

Deliberate superposition of steady flow parallel to the thermoacoustic osci llations in a stack is used to cool the steady flow as it passes through th e stack. The loudspeaker-driven refrigerator described here cools a flowing helium-argon mixture from 35 to 27 degreesC and provides additional coolin g power at a traditional cold heat exchanger. The dependence of the stack's temperature profile and of the additional cooling power on the steady flow rate are in agreement with a simple theory based on augmentation of the we ll-known thermoacoustic momentum, continuity, and energy equations with a s ingle new term in the energy equation that describes the steady flow. (C) 2 000 Acoustical Society of America. [S0001-4966(00)04712-3].