Effect of a stack on Rayleigh streaming cells investigated by laser Doppler velocimetry for application to thermoacoustic devices (L).

Abstract

A preliminary study was conducted to observe the influence of a stack on the Rayleigh streaming pattern for application to thermoacoustic devices. The velocity field was estimated from laser Doppler velocimetry measurements in a resonator first without a stack; then a stack was placed at various positions along the resonator axis for various acoustic levels. It was observed that adding a stack locally modifies the streaming pattern and that new streaming vortices appear. When the stack position approaches the location of the streaming velocity maximum or when the acoustic velocity amplitude is increased, the amplitude of additional acoustic streaming vortices at the ends of the stack increases.