Study of heat engines based on novel principles exploiting transport phenomena of the acoustic solitary waves

本研究旨在建立一种新的利用声孤波(以下简称孤波)传输现象的热机原理。在解析推导质量、动量和能量传输量的同时，结合数值模拟进行了声孤立波的实验，以验证它们的存在。由此得出结论：声孤立波在实际中是存在的。接下来，我们研究了放大孤立波所携带的能量流的物理机制。结果表明，当管壁向传播方向施加正的温度梯度时，确实增加了能流，并且薄板的堆叠增强了能流的增加速度。当管壁受到空间周期温度梯度时，它显示了。能量通量在一个周期内净增加。这为建立热机(原动机)的第一步扫清了障碍。这种周期性的温度分布是在环形管中实现的。设计建造了环管，并对板堆进行了试验。在上述研究的同时，还研究了管内气柱的无激波、高振幅振动的共振激励，这通常用于热声热泵。结果表明，通过串联一组谐振器，可以产生峰值为环境压力10%的压力振荡。

This study aims at establishing a novel principle of heat engines exploiting transport phenomena of the acoustic solitary waves (called solitary wave simply hereafter). While the quantities of mass, momentum and energy transfer are derived analytically, the experiments of the acoustic solitary waves are performed by combined use of numerical simulations to verify their existence. It is then concluded that the acoustic solitary waves exist in reality. Next physical mechanisms to amplify energy flux carried by the solitary waves are examined. It is revealed that when positive temperature gradient is imposed on the tube wall toward the direction of propagation, the energy flux is indeed be increased, and that a stack of thin plates enhances the rate of its increase. When the tube wall is subjected to spatially periodic temperature gradient, it is shown. that the energy flux is increased in net over one period. This clears the first step of establishing the heat engine (prime mover). Such a periodic temperature distribution is realized in a looped tube. The looped tube has been designed and constructed, while the stack of plates is tested. In parallel to the above study, studied is resonant excitation of shock-free, high-amplitude oscillations of a gas column in a tube, which is usually used for thermoacoustic heat pumps. It is shown that connection of an array of resonators has achieved to generate pressure oscillations with peak amplitude 10% of ambient pressure.