STUDY OF NONLINEAR ACOUSTIC CHARACTERISTICS OF PERFORATED CONSTRUCTION AT HIGH SOUND PRESSURE LEVELS

Based on the theory concerning the nonlinear acoustic resistance of an orifice presented by ZhaoSongling et al.,authors derived the expressions about the nonlinear acoustic resistance of the perforatedconstructions for the both circumstances of normal incidence in a standing wave tube and side branchincidence in a progressive wave tube.It is pointed out that the performance of resonance-type mufflerwill depend on the incidence pressure.Experiments were carried out in a standing wave tube and aprogressive wave tube with highly intense sound.In the experiments the highest incidence soundpressure level approached about 155 dB(ref.2×10Pa). The experimental results agree with the theoretical prediction approximately.In order to facil-itate the practical application of the theory,suggestions are made of several critical conditions ex-pressing the nonlinear behaviour of acoustic resistance.