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为研究有流动管道侧向微缝共振器的声学特性,基于离散涡方法建立了一个理论模型.管道安装共振器处利用质量和动量守恒建立间断条件,再结合离散涡模型,计算出共振器的声阻抗和吸声系数.数值模拟表明微缝处流场主要取决于脱落涡层的卷起和拍动,这与流场显示实验结果一致,并验证了半经验模型中微缝剪切层的“盖子”假设.结果还表明共振器声阻主要由声压级和切向流速度决定,声抗由背腔深度和面板厚度及末端修正决定.
In order to study the acoustic characteristics of the lateral micro-slit resonator with flowing pipe, a theoretical model is established based on the discrete vortex method.Using the conservation of mass and momentum conservation, the pipe-mounted resonator establishes the discontinuous condition, and then the discrete vortex model is used to calculate the resonator’s Acoustic impedance and sound absorption coefficient.Numerical simulation shows that the flow field at the micro slit mainly depends on the roll-up and flapping of the shedding vortex, which is in agreement with the experimental results of the flow field, and verifies that the micro-shear layer in the semi-empirical model The result also shows that the acoustic resistance of the resonator is mainly determined by the sound pressure level and the tangential flow velocity, and the acoustic impedance is determined by the depth of the back cavity, the thickness of the panel and the end correction.