Simulation of onset process of standing wave thermoacoustic engine based on thermoacoustic network theory

This work studied study the onset conditions of a standing wave thermoacoustic engine and analyzed the mechanism of thermoacoustic oscillation. Using the control differential equations of linear thermoacoustic theory, three formulas for calculating the transfer array of the stack with temperature gradient were derived. Through the comparison, the accuracies of the three formulas were obtained. Based on the thermoacoustic network theory, a self-designed standing wave thermoacoustic engine was simulated. The onset temperatures and frequencies in different charging pressures and stack spaces were calculated and compared with the experimental results. The variation trend of the calculated onset temperature by charging pressure was almost the same as the experimental result. The calculation results also indicate that different stack spaces should be chosen for different charging pressures. For the standing wave thermoacoustic engine, the optimum stack space should be 2.20-2.30 times the thermal penetration depth.