火箭发动机喷流噪声数值模拟及声振分析

为给火箭系统结构振动响应分析提供有效载荷，采用雷诺平均N S（Reynolds averaged N S，RANS）方程求解喷流流场与用非线性声学求解器（Non linear Acoustics Solver，NLAS）求解喷流声场相结合的方法，对某高超声速火箭液体发动机喷流噪声进行数值模拟.用有限元法和统计能量分析相结合的方法，求解发动机模型在噪声作用下的全频段振动响应.计算结果表明：发动机喷流噪声声压级大小与喷流流场的湍流动能密切相关，湍流强度大的位置喷流噪声声压大；喷流流场初始段混合层内产生的噪声在高频段大于过渡区内产生的噪声，但中低频段却相反.

Jet flow noise numerical simulation and acoustic vibration analysis of rocket engine

To provide a payload for the analysis on the structural vibration of rocket, combining the Reynolds averaged N S(RANS) equations for jet flow field solution with the Non linear Acoustics Solver(NLAS) for jet acoustical field solution, the jet noise is numerically simulated for the liquid engine of a hypersonic rocket. Combing the finite element method with statistical energy analysis, the full band vibration response of the engine model is solved under the effect of noise. The calculation results show that, the sound pressure level of jet noise is closely related to the turbulent kinetic energy in jet flow field and the strong jet noise pressure occurs at the position with high turbulence intensity; as to the initial part of jet flow field, the high frequency noise generated in mixing layer is bigger than that generated in transition region, while it is contrary for the low frequency noise.