双侧激励源对热声制冷谐振腔内声场分布的影响

超声磁致伸缩换能器作为热声制冷机的激励元件,其输出声场强度直接影响热声制冷的效率。为提高谐振腔内直观的声压幅值,在单侧磁致伸缩换能器激励的基础上,集合声波相干理论,应用有限元软件ATILA模拟了双侧激励情况下,不同长度谐振腔与激励相位的匹配关系对谐振腔内声压幅值的影响,并与单侧激励谐振腔内声压幅值做比较。研究结果表明:相同激励力情况下,双侧激励(170 mm受同相激励,340 mm受反相激励)谐振腔内产生的平面驻波声场更加稳定、单色性好、声压幅值是单侧激励的1.78(半波长谐振腔)/1.81倍(一个波长谐振腔),均接近于2倍关系。以上研究成果对双侧激励源的相位与谐振腔长度的匹配工作提供了实验依据。

The Influence of Bilateral Incentives on Radiation Sound Field Distribution of Thermoacoustic Refrigeration Resonator

The output sound field intensity of ultrasonic magnetostrictive transducer which is the excitation element of Thermoacoustic refrigerator affects the efficiency of thermoacoustic refrigeration directly. In order to improve the intuitive sound pressure amplitude in the resonator, the bilateral excitation was simulated by using the finite element software ATILA on the basis of the excitation of the unilateral magnetostrictive transducer and collective the theory of Acoustic Coherence. And then analyze the relationship between the resonant cavity length and the excitation phase and compare with the unilateral excitation. The results show that under the same excitation force, the two - side excitation (170mm by the same phase excitation, 340mm by the reverse excitation) resonant cavity produced more stable surface acoustic wave field, monochromatic sound pressure amplitude is unilateral excitation Of 1.78 (half-wavelength resonant cavity) / 1.81 times (a wavelength cavity), are both about 2 times relationship. The experimental results provide experimental basis for matching the phase of the bilateral excitation sources with the resonant cavity length.