液体工质对气液热声发动机性能影响的实验研究

采用气液耦合振动是降低热声发动机谐振频率和提升其压力振幅的一种有效途径。为了研究液体工质对于气液热声发动机性能的影响,本文针对水、室温离子液体EMIM]BF₄]、20%氯化钾溶液、40%和50%甲酸钾溶液五种液体工质进行了实验研究和分析。实验数据显示,在相同加热功率下,采用50%甲酸钾溶液时系统谐振频率最低,而水工质对应的谐振频率最高;40%甲酸钾溶液的压力振幅最大,而采用离子液体EMIM]BF4]时系统压力振幅最小。研究结果表明:采用密度较大的液体工质可获得较低的谐振频率,而密度大、黏度小的液体工质则有利于获得更大的压力振幅。

Experimental Study of the Influence of Liquids on Performance of a Thermoacoustic Engine With Gas and Liquid

Gas-liquid coupling oscillation is an effective way to reduce resonant frequency and to elevate pressure amplitude of a thermoacoustic engine.The influences of working liquids on the performance of a thermoacoustic engine with gas and liquid are studied experimentally.Five liquids, i.e.,water,ambient temperature ionic liquidEMIM]BF₄],potassium chloride aqueous solution with a mass concentration of 20%,and potassium formate aqueous solutions with the mass concentration of 40%and 50%respectively,are used as the liquid column in the experiments.The experimental data show that the system with 50%potassium formate aqueous solution can achieve the lowest resonant frequency at a given heating power,while water leads to the highest resonant frequency.The pressure amplitude of the 40%potassium formate aqueous solution system is the highest,contrastively,the EMIM]BF₄]results in the lowest pressure amplitude.The analysis indicates that a lower resonant frequency can be achieved by the liquid with a larger density,and that an increased liquid density and a decreased liquid viscosity are advantageous for the elevation of the pressure amplitude.