【作者】 赵忠明；

【导师】 李青；

【作者基本信息】 华中科技大学 ， 制冷及低温工程， 2009， 硕士

【摘要】 热声热机是一种新型的热机,有着传统热机无法比拟的优点。例如结构简单、没有运动部件、稳定性好、寿命长、无污染等优点,使其成为热机技术研究中的一个热点。回热器段是热声热机的关键部件。热声学的核心是回热器内气体微团的介观热力学微循环。随着热声系统实验研究的不断深入,迫切需要借助粒子成像测速仪等先进的热物理测试技术。热声系统流场的介观测量研究还存在很多空白。Micro-PIV(显微粒子图像测速)技术是上世纪末在传统PIV技术基础之上产生和发展起来的。它运用现代计算机技术、激光技术和数字图像处理技术,突破了传统单点测量的局限性,实现了高精度、无干扰的微流体全场观测。本文使用Micro-PIV系统、自制荧光示踪粒子、透明回热器段模型等搭建了热声学介观测试平台。全文工作可以分为以下几个方面:1.回顾了近几年热声技术研究进展以及激光测速在热声领域的初步研究,总结了近年来热声技术研究的若干热点方向。2.初步建立了适用于热声系统介观测量研究中示踪粒子的模型,对热声交变流场中粒子的运动进行了数值计算,得出了可用于本热声系统介观测量实验的示踪粒子的粒径范围,1并定量分析了粒径、密度、频率等参数对粒子跟随性的影响。3.自制荧光示踪粒子,设计并加工透明板叠式回热器段模型,最后搭建热声学介观测试系统,采集并处理速度场图像,分析了回热器内的流场。最后对整个实验过程中发现的问题提出了几点改进措施。更多还原

【Abstract】 Thermoacoustic engine which has incomparable advantages is a new kind of engine, different from the traditional engine. It has simple structure, no moving part, high reliability, long life-span and green gas media. So it has become a hotspot in the engine technology research. The regenerator is an important part in thermoacoustic engine. The essence of thermoacoustic technology is mesoscopic thermodynamic cycle of gas parcels in the regenerator. With the rapid development of experimental study of thermocoustics, it is urgent to draw support of particle image velocimetry and other advanced metrology of modern thermal Physics. There are a lot of blanks in the mesoscopic study of thermoacoustic flow field.Micro-PIV(Micro Particle Image Velocimetry ) has been a modification of PIV (Particle Image Velocimetry)which is a well-established technique for microscopic flows since the end of last century. It bases on modern computer technology,laser technology and digital image processing technology to provide a high precision and non-intrusive measurement technique in microscale devices, which breakthrough the traditional methods of single-point measurement.A thermoacoustic mesoscopic test platform is build based on MicroPIV system, self-made fluorescence tracer particles, and transparent regenerator section models. This thesis research work can be described as the following several aspects,1. The progress of thermoacoustic technology and laser velocimetry in this Research area is reviewed. Some recent research hotspots are summarized.2. The performance of tracer particles is very important to the experiment. A tracer particle model is constructed for experimental study of thermoacoustic mesoscopic measurement in this thesis. In the thermoacoustic oscillating flow field, a particle size range which is suitable for thermoacoustic mesoscopic measurement experiments is obtained. The particles’transient motions are investigated numerically, and the effects of several parameters, such as particle diameter and density, on particles’velocity in responses to oscillating flow are analyzed quantitatively. 3. All of the tracer particles are self-made. Several transparent regenerator models are designed and processing, then, a thermoacoustic mesoscopic test platform is build. The velocity field image in the regenerator flow field is processing and analyzed after acquisition. According to the problems found in the experimental process, several measures for improvement are put forward.更多还原