热机循环的时序波型分析

热声热机是一种新型热机，与经典热机一样都是一种周期性的振荡结构，依据其波动特点可分为驻波型、行波型和行、驻混合波型,从波动特性出发，分析了周期性振荡结构的热机的示功图特点，压力、体积振荡的相位决定了循环的方向和示功图的丰满程度,驻波型的热声机由于热声器件的影响而发生相位偏离，从而具有了能量的传递与转换能力；而行波型热声机也由于热声器件的影响发生相位偏移，使波动结构中具有了一定的驻波成份，经典热机中不存在纯粹的驻、行波结构，而是2种波型的混合；只是由于卡诺循环接近于驻波相位，所以示功图狭长，而斯特林、布雷顿循环接近于行波相位，所以示功图比较丰满,热声热机与经典热机一样都是行、驻混合波型，从而通过周期振荡特点以及热力学循环，为经典热机循环和热声热机循环建立起联系的桥梁．

Time serial waveform analysis of thermodynamic cycle of engine

As a new type of engine,the thermoacoustic engine is a periodic vibration structure as well as a classical engine.The thermoacoustic engine can be divided into three classes according to the characteristic of the vibration-standing wave, traveling wave and the composite according to the phase between the pressure and fluid velocity. First analyzed were the characteristics of the pressure-velocity(p-V) chart from the view of wave characteristics. The results indicate that the phase between pressure and fluid velocity determines voluminous extent of the p-V chart.Due to the effect of the apparatus of thermoacoustic, the phase between pressure and fluid velocity shifts from the phase of standing wave and traveling wave respectively. So it is a composite wave in thermoacoustic engines.Also studied was the thermodynamic cycle of a classical engine from the view of wave. There is no pure standing wave or traveling wave in classical engines. But because the phase between pressure and fluid velocity approaches to standing wave phase for Carnot cycle, the area of p-V is small; whereas the area is large for Stirling and Brayton cycle because the phase approaches traveling waves.Analysis indicates that it is a composite wave in classical engine as well as in thermoacoustic engines, not a pure wave (standing wave or traveling wave). A bridge is built between classical engines and thermoacoustic engines by the characteristics of their vibration and thermodynamic cycles.