管束穿孔板的管腔耦合共振吸声机理研究

为了揭示管束穿孔板共振吸声结构的吸声机理,利用热黏性条件下基于有限元算法的管束穿孔板仿真模型,研究了平面声波正入射条件下,管束穿孔板内部声场分布特征,并利用阻抗管对吸声系数的理论仿真结果进行了试验验证.结果表明,管束穿孔板在低频主要靠腔体共振吸声,在高频主要靠管共振吸声,管束穿孔板整体呈现出较为明显的管腔耦合共振吸声特征。管束穿孔板共振时管中声强和质点法向振速较大,高频次吸声峰频点处管中和腔中均有驻波形成,频率越高驻波数量越多.管束穿孔板的耦合共振受到管长、腔深、穿孔率和管内径等参数变化的影响,管长对高频耦合共振的影响最大,管长增大使高频主吸声峰频点移向低频,并使相邻主吸声峰之间的间距减小. 

The tube-cavity coupling resonance sound absorption mechanism of the perforated panel resonator with tube bundles

In order to reveal the sound absorption mechanism of the perforated panel resonator with tube bundles(PPR-TB),using the finite element algorithm based on simulation model of the PPR-TB under the thermal viscous conditions,the sound field distribution characteristics of the PPR-TB at the normal incidence of plane sound waves.And the theoretical simulation results are verified by the experiments in an impedance tube.The results show that the PPR-TB mainly relies on cavity resonance sound absorption at low frequency and tube resonance sound absorption at high frequency.The PPR-TB as a whole displays a more obvious tube-cavity coupling resonance sound absorption characteristics.The amplitudes of sound intensity and particle normal vibration velocity in the tube during resonance are larger.There are standing waves in both the tube and the cavity at the high frequency minor sound absorption peak points.The higher the frequency,the more standing waves there are.The coupling resonance of the perforated panel resonator with tube bundles are affected by the tube length,cavity depth,perforation ratio,tube inner diameter and other parameters.The tube length has the greatest impact on high-frequency coupling resonance.The increase of tube length shifts the frequency points of the high frequency main sound absorption peaks to the lower frequencies,and the distance between the adjacent main sound absorption peaks is reduced.