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.