Abstract:
Current thermoacoustic refrigerator designs, based on linear actuation style moving-coil electrodynamic transducers (loudspeakers), are limited by their power-handling capacity. Loudspeakers introduce additional design constraints by the fact that they are required to simultaneously serve three separate functions: they must provide the electromotive force, the mechanically resonant elastic suspension, and a flexure seal (usually bellows). A fixed barrier within the toroidal resonator permits the excitation of a (lambda)/2 standing wave when the entire toroid is driven into rigid-body torsional oscillation. The barrier eliminates the need for a flexure seal. The suspension (spokes) and the drive mechanism are external to the resonator. This increases the number of options available for the drive and resonant suspension and allows these functions to be optimized independently. The first TRT-TAR device, which did not include stacks and heat exchangers, generated predictable standing-wave gas resonances which were tuned to the first or second torsional resonances by adjustment of the gas mixture concentration. A complete, fully instrumented TRT-TAR, which includes a single stack and heat exchanger pair, has been fabricated and tested at low amplitudes [Work supported by the Office of Naval Research.]