Abstract:

It has been demonstrated that the bulk of time-averaged heat transfer between the oscillating fluid and a thermoacoustic couple is concentrated towards the edges of the stack plate. Previous numerical studies which have considered thermoacoustic couples of finite thickness have used a rectangular form for the plate edge. In practice however, current manufacturing practices allow for a variety of stack edges which may improve the efficiency of heat transfer and/or reduce entropic losses. In this numerical study, the performance of a thermoacoustic couple is investigated at selected drive ratios and using a variety of stack plate edge profiles. Results indicate that stack profiles with streamlined shapes improve the rate of heat transfer at low drive ratios but retard the rate of heat transfer at higher drive ratios due to reduced residence time of the fluid in contact with the stack plate. Conversely, enlarged and blunter stack edges perform relatively poorly at low drive ratios, but are the most effective at higher drive ratios despite creating the highest rate of entropy generation.