Analysis and performance of a large thermoacoustic engine
Analysis and performance of a large thermoacoustic engine
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DOI：
10.1121/1.403896
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发表时间：
1992-09
影响因子：
2.4
通讯作者：
G. Swift
中科院分区：
文献类型：
--
作者：
G. Swift
对一台直径为13 cm的热声发动机进行了测量和分析。在其最强大的工作点，使用13.8 bar氦气，发动机提供630 W的外部声负载，将热量转换为所提供的声功率，效率为9%。在低声振幅，其中（线性）热声理论预计将适用，温度差和频率的测量与理论的预测在4%以内，在跨越因素的条件下，平均压力为4，压力振幅为10，频率为6，气体声速为3。但是压力振幅的平方与加热器功率的测量值与理论预测值相差20%，是结果中估计不确定性的两倍。在较高的压力振幅（高达16%的平均压力），甚至更显着偏离现有的热声理论观察。确定了这种振幅依赖性偏差的几个原因，包括声波中的共振增强谐波含量，以及热声热交换器中的新的一阶温度缺陷。这些原因解释了高振幅测量与现有（线性）理论的部分（但不是全部）振幅依赖性偏差。
Measurements and analysis of a 13‐cm‐diam thermoacoustic engine are presented. At its most powerful operating point, using 13.8‐bar helium, the engine delivered 630 W to an external acoustic load, converting heat to delivered acoustic power with an efficiency of 9%. At low acoustic amplitudes, where (linear) thermoacoustic theory is expected to apply, measurements of temperature difference and frequency agree with the predictions of theory to within 4%, over conditions spanning factors of 4 in mean pressure, 10 in pressure amplitude, 6 in frequency, and 3 in gas sound speeds. But measurements of the square of pressure amplitude versus heater power differ from the predictions of theory by 20%, twice the estimated uncertainty in the results. At higher pressure amplitudes (up to 16% of the mean pressure), even more significant deviation from existing thermoacoustic theory is observed. Several causes of this amplitude‐dependent deviation are identified, including resonance‐enhanced harmonic content in the acoustic wave, and a new, first‐order temperature defect in thermoacoustic heat exchangers. These causes explain some, but not all, of the amplitude‐dependent deviation of the high‐amplitude measurements from existing (linear) theory.