固体火箭发动机喷管阻尼数值计算方法及规律研究

从声学角度出发,参考稳态波衰减法,综合考虑喷管辐射损失及对流损失,建立固体火箭发动机喷管阻尼声能共振数值计算方法,通过与阻抗管法测量的试验结果对比验证仿真方法,并探究喷管喉径、监测点位置、声源强度及平均压力对喷管阻尼的影响,结果表明:数值计算结果与试验结果吻合较好,表明该研究建立的仿真方法有效;喷管阻尼随喉径的增大而增大,进而使声腔内形成稳定驻波时的压力振幅降低。传声特性分析结果表明:喷管喉径增大,声功率透射系数提高,使喷管阻尼增加;监测点位置及声源强度不会影响喷管阻尼大小,但会影响压力振幅大小;喷管阻尼及压力振幅均与平均压力大小无关。

Numerical calculation method and laws for nozzle damping of solid rocket motor

Here,from the perspective of acoustics,referring to the steady-state wave attenuation method and comprehensively considering nozzle radiation loss and convection loss,a numerical calculation method of sound energy resonance for nozzle damping of solid rocket motor was established.The simulation method was verified by comparing the numerical results with the test results measured using the impedance tube method,and effects of nozzle throat diameter,monitoring point position,sound source intensity and average pressure on nozzle damping were explored.The results showed that the numerical results agree better with the test ones,so the established simulation method is effective;nozzle damping increases with increase in throat diameter to make pressure amplitude be reduced when a stable standing wave is formed in acoustic cavity.The analysis results of sound transmission characteristics showed that nozzle damping increases with increase in nozzle throat diameter and sound power transmission coefficient;position of monitoring point and sound source intensity can’t affect nozzle damping,but affect pressure amplitude;nozzle damping and pressure amplitude are independent of average pressure.