Numerical investigation of a thermoacoustic engine core via heat transfer calculations coupled with acoustic field analyses

Synthetical optimization of the structure dimension for the thermoacoustic regenerator

“…Fundamentals of physical principles underlying the regenerator were investigated and analyzed in previous papers, [6,7] while the regenerator's parameters were optimized by several researchers. [7][8][9][10][11][12] Swift [7] studied the hydraulic radius r h in the thermoacoustic system and obtained the empirical values: r h /δ k ∼ 1 for standing wave engine and r h /δ k 1 for traveling wave engine, where δ k is the thermal penetration depth. Tijani [8] studied a standing wave thermoacoustic cooler and put forward that r h = 1.25δ k was optimal for the cooling power, r h = 2.0δ k led to the lowest temperature, and the highest efficiency could be reached when r h = 1.5δ k .…”

“…Tijani [11] experimentally investigated the effect of Prandtl number on the performance of a thermoacoustic refrigerator using gas mixtures. Kazuto [12] considered correlations of the local Nusselt number distribution and analyzed heat transfer characteristics of the oscillatory flow in the engine core via numerical simulations.…”

“…However, those publications [7][8][9][10][11][12] were unilateral to understand the optimal condition for the thermoacoustic conversion. Most of those regenerator optimizations [7][8][9][10][11][12] analyzed parameters of the working field, working gas and the hydraulic radius, whereas the quantitative investigation of important pa-rameters, for example, the length of the regenerator, on the behavior of thermoacoustic devices was still lacking.…”

“…However, those publications [7][8][9][10][11][12] were unilateral to understand the optimal condition for the thermoacoustic conversion. Most of those regenerator optimizations [7][8][9][10][11][12] analyzed parameters of the working field, working gas and the hydraulic radius, whereas the quantitative investigation of important pa-rameters, for example, the length of the regenerator, on the behavior of thermoacoustic devices was still lacking. In the previous design, [13][14][15][16][17][18][19][20][21][22][23][24][25] the selection of the regenerator length was dependent on the experience, which caused the design with some blindness and results without prescient considerations, as well as the limited performance rather than the optimal.…”