Experiments with a flow-through thermoacoustic refrigerator

Deliberate superposition of steady flow parallel to the thermoacoustic oscillations in a stack is used to cool the steady flow as it passes through the stack. The loudspeaker-driven refrigerator described here cools a flowing helium–argon mixture from 35 to 27 °C and provides additional cooling 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 well-known thermoacoustic momentum, continuity, and energy equations with a single new term in the energy equation that describes the steady flow.