无喷管助推器非定常动边界内流场数值模拟

无喷管助推器依靠药柱的扩张面实现对气流的加速,燃面的线性增加及喉面的指数增加,使其内流场呈现明显的非定常性;侵蚀燃烧、压强的不均匀分布及药柱变形,使无喷管助推器的工作过程十分复杂。通过对FLUENT软件进行二次开发,建立了无喷管助推器的非定常动边界内流场数值模型,考虑了推进剂的点火过程和侵蚀燃烧,可获得各个时刻的燃面位置及内流场分布,从而可对发动机的内弹道性能进行较准确地预示。通过对某无喷管助推器的工作过程进行模拟,内弹道计算曲线与试验曲线吻合得较好。

Numerical simulation on unsteady dynamic boundary internal flow field of a nozzleless booster

The nozzleless booster makes use of grain expanded area to realize acceleration of gas flow,linear increase of burning area and exponent increase of the throat area,which can make internal flow field present obvious non-stationarity.Erosive combustion,non-uniform pressure distribution and grain deformation make the working process of nozzleless booster very complex.Through secondary development for FLUENT software,the numerical model of unsteady dynamic boundary internal flow field was derived.Ignition process and erosive combustion were taken into consideration to obtain burning area position and internal flow field distribution at different times,so that internal ballistic properties of the propellant can be predicted accurately.Working process of a nozzleless booster was simulated.The internal ballistic calculation curve agreed well with experimental curve.