某大口径轻武器射流噪声的小波分析与数值模拟

Wavelet Analysis and Numerical Simulation of Jet Noise induced by a Large Caliber Small Arms

针对某带膛口制退器的大口径轻武器射流噪声问题,在实验研究和数据分析基础上,对膛口噪声的气动特性进行探究。利用小波分析方法对实验测得的噪声数据进行分析,将膛口冲击波与膛口脉冲噪声的波形加以区分;采用计算流体力学与计算气动声学耦合算法对膛口噪声进行数值模拟,并将测点位置的噪声数值模拟结果与实验结果进行对比分析,验证该计算方法的可行性;分析了膛口制退器内的激波分布及带膛口装置的膛口噪声场指向性分布。研究结果表明:膛口噪声成分复杂,频带宽且声能较高,膛口制退器引起膛口周围流场的侧向分流,从而影响膛口噪声的指向性分布。

The aerodynamic characteristics of muzzle noise are studied based on experimental and numerical research on jet noise induced by complex flows discharging from a large caliber small arms with a muzzle brake. The measured noise data are analyzed to distinguish the muzzle shock wave from muzzle impulse noise by the wavelet transform method. The muzzle noise is numerically simulated by a CFDCAA hybrid method. The feasibility of the proposed method is proven by comparing the simulated results with the test results. In addition,the distribution of shock wave in muzzle brake and the directivity of muzzle noise field are analyzed based on the numerical simulation. The results indicate that the muzzle noise has a wide spectrum with high sound energy and complex components. It is found that the muzzle brake causes the lateral diversion of flow field around the muzzle,thus affecting the distribution of muzzle flow noise.