为了揭示固体火箭发动机推力振荡特性,以大型助推器P230的缩比发动机为基础,使用大涡模拟方法,对障碍物旋涡脱落诱发的振荡流场开展数值模拟,通过对比燃烧室压力、推力的振频和振幅,总结了推力振幅的估算方法.研究结果表明,推力振幅对压力振幅放大机理的关键参数是喉通比,放大比例与喉通比成反比;奇数阶声振型对推力振幅的贡献最大,偶数阶声振型对推力振幅的影响可以忽略,旋涡脱落对推力振幅的作用小于奇数阶声振型,且随涡/声耦合程度的增大而增强.%In order to discover the mechanism of thrust oscillation characteristics in solid rocket motors, large-eddy simulation with Wall-Adapting Local Eddy-Viscosity subgrid-scale turbulence madel is carried out to study the oscillating flow field induced by obstacle vortex shedding based on the subscale motor of P230. An integrated method is presented to describe the relationship between thrust amplitude and pressure amplitude. The results indicate that the ratio of thrust amplitude to pressure amplitude is mainly determined by the throat to port area ratio J, and it varies inversely as J. It is concluded that odd-order acoustic modes have the greatest contribution to the thrust amplitude, while the effect of even order acoustic modes on thrust amplitude can be ignored. The contribution of vartex-shedding to the thrust amplitude is less than that of the odd order acoustic modes, and it increasea with the level af vortex sound coupling.
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