简介:Thermoacoustic refrigeration systems generate cooling power from a high-amplitude acoustic
standing wave. There has recently been a growing interest in this technology because of its simple and
robust architecture and 简介:Thermoacoustic refrigeration systems generate cooling power from a high-amplitude acoustic
standing wave. There has recently been a growing interest in this technology because of its simple and
robust architecture and its use of environmentally safe gases. With the prospect of commercialization,
it is necessary to enhance the efficiency of thermoacoustic cooling systems and more particularly of
some of their components such as the heat exchangers. The characterization of the flow field at the
end of the stack plates is a crucial step for the understanding and optimization of heat transfer between
the stack and the heat exchangers. In this study, a specific Particle Image Velocimetry measurement(PIV) is
performed inside a thermoacoustic refrigerator. Acoustic velocity is measured using synchronization
and phase-averaging. The measurement method is validated inside a void resonator by successfully
comparing experimental data with an acoustic plane wave model. Velocity is measured inside the
oscillating boundary layers, between the plates of the stack, and compared to a linear model. The
flow behind the stack is characterized, and it shows the generation of symmetric pairs of counterrotating
vortices at the end of the stack plates at low acoustic pressure level. As the acoustic pressure
level increases, detachment of the vortices and symmetry breaking are observed.详细>