The Effect of Porosity and Vibration on the Flow across the Stack in Thermoacoustic Technology

The thermodynamic cycle of the alternative thermoacoustic green technology relies on the complex fluid flow and energy transfer interactions between the oscillatory flow of the acoustic wave and the solid surface of porous media known as a stack. Additive manufacturing enables a variety of porous designs to be incorporated into the system; however, understanding the flow dynamic aspects is crucial to minimizing losses. This paper presents experimental data on the velocity and vibration characteristics of acoustic flow across parallel plates, open-cell foam, and gyroid structures. Data are presented for the oscillatory thermoacoustic flow condition with a resonance frequency of 23.2 Hz and a drive ratio, DR, between 0.6% and 2.5%. The results suggest that porous designs influenced the amplitude of thermoacoustic flow and the vibration of the resonator’s wall. This information contributes toward future optimization of thermoacoustic stack designs based on specific performance requirements, whether for maximizing energy transfer or ensuring structural stability.