Thermoacoustic refrigeration demonstration

A portable device for demonstrating thermoacoustic cooling is developed using off‐the‐shelf components: the Morel MW‐142 5‐in. woofer and the Selenium HL14‐25 horn. Acoustic peak pressure amplitudes of 19 kPa (19% of mean pressure) have been measured (without stack) using atmospheric air as the working fluid. Measurements of spectra, quality factors, stack temperature differences, and heat pumping capacity are compared to DeltaE models. Use of off‐the‐shelf components leads to design considerations not encountered in full‐scale devices. For example, the high mechanical resistance of the driver, which was intended for audio reproduction, dictates against making the driver coresonant with the resonator, as is common when the driver is designed for operation at a specific frequency. [Work supported by NSF and ONR.]