从线性热声理论出发,通过求解并简化交变流动换热系数,对规则流道的换热进行较为全面的讨论,得到平板以及圆管流道回热器换热系数的简化表达式。考虑固壁温度波动后,发现对于一定结构的回热器,换热系数是六个无量纲量的函数。特别针对低温情况下,讨论了影响换热的主要因素以及增强换热的方法。
Based on the linear thermoacoustic theory, heat transfer characteristics of compressible oscillating flow in simply structured regenerators are analyzed. The results of heat transfer analysis are applicable at low temperatures for considering temperature oscillation in the solid. It has been found that Nusselt number is the function of six nondimensional parameters when the structure of the regenerator is fixed. These parameters are discussed respectively. Simple expressions of Nusselt num- bers for both parallel plates and circular tubes structured regenerators are derived. Special attentions are paid to cryogenic regenerators. Main factors affecting the heat transfer are discussed. Possible approaches to enhance heat transfer in a thermoacoustic regenerator are given.