Heat Transfer in Acoustic Resonance Tube and Its Application to Small-Capacity Refrigerator.

由于对环境的重要性，人们越来越注意开发用于空间和其他小容量应用的声共振制冷机。该项目侧重于通过热声学对传热机制的基本理解。建立了由声激励器、谐振管和电堆组成的声制冷机模拟模型，测量了声制冷机的声学特性和沿着电堆的温度分布。本项目取得的主要成果如下：1.在使用氦气或氮气作为工作流体的情况下，整个电池堆的最大温差达到30 K。声学驱动器的改进将使冰箱实用化的可能性大大提高.使用线性化声学理论很好地预测了声场，而线性化理论在较高的声振幅下给出了较差的结果。改进模型考虑非线性效应 ...更多信息 有效地预测了高振幅区声场的基本特性.声幅值、声堆长度、声堆相对于声幅值分布的位置对声堆沿着方向的温度分布有显著影响。叠层板之间的距离对叠层中的温度差和声波相位差等热声特性起着重要的作用。存在一定的最佳叠板间距。当声幅值较小时，线性化热声理论能较好地预测温度分布，而当声幅值较高时，非线性效应对温度分布有显著影响。考虑到声雷诺应力的影响以及由此产生的声流和涡扩散系数，对预测模型进行了改进，使其与实验结果更符合。在堆栈表面的传热将需要进一步的实验研究，但本项目的目前结果给出了令人满意的理解的主要特点的热声制冷机。少

Increasing attention has been given to the development of an acoustic resonance refrigerator for space use and other applications of small-capacity, owing to the environmental importance. This project focused on the fundamental understanding of the heat transfer mechanism by thermo-acoustics. A simulated acoustic refrigerator model was constructed, consisting of an acoustic actuator, a resonance tube and a stack, and acoustic characteristics as well as the temperature distribution along the stack were measured. The results obtained in this project were summarized as follows.1. Maximum temperature difference across the stack reached 30 K,using helium or nitrogen gas as a working fluid. The Improvement of acoustic actuator will make the possibility of practical refrigerator high.2. The acoustic field was well predicted using a linearized acoustic theory, while the linearized theory gave poor results at higher acoustic amplitude. Improving the model to taking into account the nonlinear ef … More fect, the fundamental characteristics of acoustic field could be predicted even at high-amplitude region.3. Temperature distributions along the stack were significantly affected by the acoustic amplitude, stack length, the position of stack relative to the amplitude distribution. The distance between successive stack plates plays an important role on the thermo-acoustic behavior including the temperature difference as well as the phase difference of acoustic wave across the stack. Some optimum stack-plate distance existed. When the acoustic amplitude was at lower level, the linearized thermo-acoustic theory could well predict the temperature distribution, while at high amplitude non-linear effect became to have a significant influence on the temperature distribution. Taking into account the effect of acoustic Reynolds stress and resulting acoustic streaming and eddy diffusivity, the prediction model was improved to give better agreement with the experimental results. Further experimental investigation will be needed in the heat transfer at the stack surface, but the present results of this project gives satisfactory understanding of the principal feature of the thermo-acoustic refrigerator. Less