气-液双作用热声发动机结构参数不一致性对系统热声转换特性的影响

摘要

针对气-液双作用行波热声发动机结构参数不一致性对系统热声转换特性的影响进行了数值模拟分析,分别讨论了回热器长度、液体活塞摩擦阻力以及液体活塞质量不对称的情况下,系统热声转换特性的变化.计算结果表明,仅改变一个基本单元的一个特定的结构参数时,整个气-液双作用行波热声发动机性能参数均发生改变,并且表现出不对称性.系统结构参数的不一致性对体积流率、压力振幅、相位以及气体温度的沿程分布均有明显影响.回热器产生的净声功率受结构参数不对称性影响显著,甚至可能出现某一基本单元回热器不产生声功率或消耗声功率的情况,值得重点关注.%Numerical simulation of a double-acting traveling-wave thermoacoustic engine with liquid piston was carried out, analyzing the influence of asymmetric regenerator length, water column resistance and water column mass on the performance of the engine. According to the simulation, changing only one structure parameter of a single unit causes all the performance parameters of the whole engine to vary asymmetrically. The asymmetric structure has a significant impact on the distribution of volume flow rate, pressure amplitude, phase angle and the temperature along the whole engine. Moreover, the net acoustic power generated by the regenerator varies significantly, and the regenerator may even dissipate acoustic power.