行波热声发动机中Gedeon直流定量研究

Quantitative investigation on Gedeon streaming in traveling wave thermoacoustic engine

针对行波热声发动机的环路结构可能引起声场Gedeon直流损失的问题,对热声发动机环路内的Gedeon直流进行了定量研究,从而进一步提高行波热声发动机的热效率.分析了Gedeon直流的产生和作用机理,基于线性热声理论,建立了热声回热器的简单焓流模型.利用实验测得的回热器温度数据,通过求解焓流模型,分析了Gedeon直流的规模及其对回热器温度分布的影响.结果表明,利用简单焓流模型计算得到的Gedeon直流流率与实验结果吻合较好.Gedeon直流对回热器的轴向温度分布影响显著,当Gedeon直流流率的绝对值达到2.0 g/s时回热器的轴向温度就已经严重偏离线性分布,此时回热器的效率较低.

The feedback tube of traveling wave thermoacoustic engine provides a passage for Gedeon streaming, which may lead to large heat loss and degrade the performance of the engine. A quantitative investigation on Gedeon streaming in the torus of thermoacoustic engine was carried out to further improve the thermal efficiency. After analyzing the generating and working mechanism of Gedeon streaming, a simple enthalpy flux model of regenerator was set up based on linear thermoacoustic theory. With measured temperature data, the scale of Gedeon streaming and its effect on the temperature profile along the regenerator was analyzed quantitatively by solving the enthalpy model. Computational and experimental results were in relatively good agreements. Results showed that Gedeon streaming had large effect on the temperature profile along the regenerator. When Gedeon streaming flux reached 2.0 g/s, the temperature profile already obviously deviated from linear profile and the regenerator had low efficiency.