容腔调相的单级行波热声发动机起振特性

Onset characteristics of a single-stage looped traveling wave thermoacoustic engine with compliance tube

将容腔结构引入单级环路行波热声发动机系统中进行相位调节,分析了不同容腔位置、容腔内径和容腔长度时系统的起振特性。基于线性热声理论,采用网格传输矩阵数值方法求解系统的起振频率和起振温差;此外,将计算结果与实验结果进行了对比,验证了计算方法的合理性。结果表明：容腔结构可以明显改善系统的起振特性,系统起振温差大幅下降;不同容腔位置处,热机起振特性差异明显;存在最优的容腔内径和容腔长度组合,使得起振温差最低,而容腔尺寸对热机起振频率的影响较小。

A compliance tube is introduced into a single-stage looped traveling wave thermoacoustic engine for phase adjustment. The engine＇s onset characteristics with various locations, inner diameters and lengths of the compliance tube are analyzed. The oscillation frequency and onset temperature difference are calculated by the grid transfer matrix method, based on the linear thermoacoustic theory. The calculated results are then compared with the experimental results to verify the rationality of the calculation method. The calculated results show that the compliance tube can improve the engine onset characteristics, which dramatically lowers the onset temperature difference. The location has significant influence on the onset characteristics, and there exists optimal inner diameter and corresponding length of the compliance tube to achieve the lowest onset temperature difference, while the influence of the compliance tube size on the oscillation frequency is not apparent.