基于多场协同机理的热声回热器性能表征与优化研究

The objective of this program is to study the process of generating and disseminating of sound wave in the regenerator. On the basis of the characterization of physical parameters of different materials, all of the research will be carried out combining numerical simulation and experimental measurement by usingthe methods ofstructural acoustic radiation theory and multi-field synergistic coupling. Then the excitation mechanism of the thermoacoustic effect on the regenerator made of single coating materials as well as composite coating materials will be analyzed. On this basis, we will study the multi-field synergy mechanism, such as temperature field, pressure field(sound field), structural flied, ensuring that each two of the above fields are homologic with each other in flow channel of the regenerator,strengthening the coupling effect of thermal acoustic emission spectrum and the practical sound-field spectrum between various materials.Therefore, the optimization mechanisms, to reduce the temperature threshold of regenerator, and improve the conversion efficiency between heat and sound, will be proposed.Thus the multi-field synergic thermoacoustic theory, which based on the characterization of physical parameters of regenetators made by different materials, will be brought forward. It is a new perspective to develop the thermoacoustic theory, which is able to reveal the basic law of the conversionbetween thermal energy and sound energy as well as the energy transportation processes. This research not only has important theoretical and application values for the thermoacoustic engine, but also possesses important reference value for all kinds of regenerative cryocoolers .

基于多场协同机理，采用回热器材料性能表征、结构声辐射理论、多场协同耦合等手段，和数值仿真优化与多种实验测量相结合的方法，在表征多种回热器材料物性参数的基础上，研究声波在回热器中产生、传播和发展的整个过程，并由此分析单一及复合镀膜等回热器材料热物性对热声效应的激发机制，辨析回热器中温度场、压力场（声场）、流场（速度场）、结构场等多场协同机理，确保回热器流道中温度场与声场、声场与结构场、流场与压力场等协同一致，强化回热器填料热声发射谱和实际声场频谱的耦合作用，并在此基础上提出优化机制，以期降低回热器的温度阈值、提高回热和热声转换效率，从而提出一种回热器材料特征因子、增强回热器热声效应、揭示热能与声能相互转换和能量输运过程中的基本规律的多场协同热声理论，从新的角度发展热声效应理论。课题研究成果不仅对热声热机具有重要的理论与应用价值,而且对所有回热式低温制冷机均具有重要的参考价值。

回热器是研制热声热机、低温制冷机及其性能提高的物质基础和保障。充分认识并正确对回热器性能进行表征，对热声热机及其相关设备的研究、生产和择优选用具有非常重要的实际意义。.课题针对热声热机回热器材料特性、结构声激励、温度场、声场、及其频率特性等直接影响热声热机转换效率的因素进行了深入研究，提出一种通过表征热声回热器材料特性，利用多场协同机理，将热声回热器中的流场、温度梯度场、速度场、压力场、浓度场（充气压力影响）、声激励和声辐射等协同一致，以达到参数耦合和优化、进而实现高效的热声转换效率，并对热能和声能相互转换和能量输运过程中的基本规律进行深入研究。根据对材料特性和耦合场的研究结论，对四分之一波长驻波热声发动机回热器的设计进行理论指导，确定板叠间距、板叠位置、谐振管长度、谐振管半径、板叠长度以及谐振腔对高频微型热声发动机起振温度和工作性能的影响。同时建立了四分之一波长高频热声发动机的数值研究模型，对该热声发动机的场协同现象进行了进一步的探讨。.课题从一种回热器材料的物性特征参数出发，到基于提高回热器热声效应的多场协同理论、揭示热能与声能相互转换和能量输运过程中的基本规律，从新的角度发展了热声效应理论。