火工分离螺母作动噪声的预示和解耦

Actuation Noise Prediction and Decoupling of Pyrotechnic Separation Nut

火工分离装置在水下武器应用中,可能会由于其作动噪声过大的问题给目标带来暴露的风险。利用有限元+边界元的数值计算方法,建立了火工分离螺母作动噪声的仿真预示模型,展示了分离过程中瞬态辐射噪声的传播过程,分析了火工分离螺母作动噪声的来源和产生机理,结合试验和仿真模型计算了各声源的辐射声功率,对噪声源进行了定量解耦。研究结果表明,在10~6000 Hz的频段内,内套筒撞击的贡献量约为50%,螺母瓣撞击的贡献量约为23%,燃烧噪声的贡献量不到1%,但是在低于400 Hz的低频段内,燃烧噪声的贡献较大,约为22%,仿真结果与试验测试结果一致性较好。

The pyrotechnic separation device may bring the risk of exposure to a target due to its excessive actuation noise in its application in underwater weapon.Combined with the finite element and boundary element method,a numerical model is established to predict the actuation noise of pyrotechnical separation nut,which realizes the visualization of transient radiated noise during the separation process.The validity of the numerical model is verified by experiments.The source and generation mechanism of actuation noise are analyzed,and the noise source is quantitatively decoupled by calculating the sound power based on the test and simulation model.The results show that,in the frequency band of 10~6000 Hz,the contribution of the impact of inner sleeve is about 50%,and the contribution of the impact of nut flap is about 23%.The contribution of combustion noise is less than 1%,but in the low-frequency band below 400 Hz,the contribution of combustion noise is more significant,about 22%.