软性多孔材料圆柱降噪特性实验研究

空腔噪声为气动噪声领域中重要的一部分,声衬作为一种有效的降噪措施,其原理为微穿孔板吸声体,即多个亥姆霍兹共鸣器并联,通过激发背腔共振吸收声能。声衬的吸声效果受到多个结构参数的影响,针对低速空腔气动噪声问题,通过微穿孔板吸声体原理对声衬进行多参数混合设计,并将其加装到空腔中,对比加装声衬前后空腔噪声的频谱特性,评估声衬在空腔噪声问题中的降噪效果,分析加装声衬对空腔噪声的自激振荡及声共振产生的影响。

Experimental inverstigation on Reduction of cylinder noise by soft porous material

In the field of aerodynamic noise, cavity noise is an important part, and acoustic liner. As an effective noise reduction measure, the principle of sound absorption is the principle of micro-perforated plate absorber, that is, multiple helmholtz resonators are connected in parallel to absorb sound energy by excitation resonance of the back cavity.The sound absorption was affected by various structure parameters of the lining. Aiming at the problem of aerodynamic noise in the low speed cavity, this paper makes a multi-parameter mix design of the sound liner through the principle of micro perforated plate sound absorber, and adds it to the cavity. The spectral characteristics of cavity noise before and after the installation with acoustic liner were compared, and the noise reduction effect of the sound liner in the cavity noise problem was evaluated. The influence of adding acoustic liner to the noise of the self-excited oscillation cavity and the effect of the acoustic resonance were analyzed.