Mesoscopic Study On A Thermoacoustic Stack Regenerator

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.