Feng Ye, Tang Ke, Jin Tao, Zhang Kaihao, Yang Rui
Department of Energy Engineering, Zhejiang University, 38 Zheda Road, Hangzhou 310027, China.
Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou 310027, China.
J Acoust Soc Am. 2017 Oct;142(4):1730. doi: 10.1121/1.5004541.
Gedeon streaming is known to considerably deteriorate the thermal efficiency of a traveling-wave thermoacoustic engine with looped configuration. The time-average pressure drop induced by a jet pump can efficiently suppress the Gedeon streaming. In this study, such suppression mechanism of the jet pump is investigated, and the emphasis is put on the effects of the dimensionless rounding, the taper angle, and the cross-sectional area ratio. An experimental apparatus has been set up to measure the time-averaged pressure drop induced by the jet pumps in oscillatory flow. Controlled experiments and characterization reveal the time-averaged pressure drop and working efficiency increase with a rise in dimensionless rounding when it is less than 0.15. For jet pumps with the fixed opening areas, the taper angle in the range from 3° to 9° is capable of producing a larger time-averaged pressure drop with a higher working efficiency, and the change of taper angle has little effect on the performance. However, performance degradation is observed as the taper angle increases beyond 9°. Moreover, when the taper angle ranges from 3° to 9°, the time-averaged pressure drop and working efficiency can be improved by increasing the cross-sectional area ratio.
众所周知，热狄昂流会显著降低具有回路配置的行波热声发动机的热效率。射流泵引起的时间平均压降能够有效抑制热狄昂流。在本研究中，对射流泵的这种抑制机制进行了研究，重点关注无量纲圆角、锥角和横截面积比的影响。搭建了一个实验装置，用于测量振荡流中射流泵引起的时间平均压降。控制实验和特性分析表明，当无量纲圆角小于0.15时，时间平均压降和工作效率会随着无量纲圆角的增加而提高。对于开口面积固定的射流泵，3°至9°范围内的锥角能够产生更大的时间平均压降和更高的工作效率，并且锥角的变化对性能影响很小。然而，当锥角超过9°时，性能会下降。此外，当锥角在3°至9°范围内时，通过增加横截面积比可以提高时间平均压降和工作效率。
