火箭发动机斜切喷管流场与推力特性的数值模拟研究

Numerical simulation on the flow field and thrust characteristics of scarfed nozzle of rocket motor

为研究固体火箭发动机斜切喷管流场与推力特性,采用非定常可压缩N-S方程与Realizable k-ε湍流模型相结合的方法,并运用混合网格技术,对不同角度斜切喷管的流场特性与推力特性进行数值模拟研究。结果表明,对于斜切喷管发动机,当喷管入口采用倾斜安装形式时,会存在一定的质量流量损失,喷管实际质量流量为理论流量的0.938;对于不同角度的斜切喷管,喷管喉部与喷管扩张段对称结构部分的速度场分布状况基本相同,而在喷管扩张段非对称部分,速度场分布存在一定的单边现象;当喷管斜切角度从45°增大到90°时,喷管轴向推力F x线性增大,侧向推力F y线性减小,推力偏转角度则从2.323°减小到0.063°,但对发动机喷管中燃气的质量流量与喷管总推力的影响不大。

In order to study the flow field and thrust characteristics of the scarfed nozzle of solid rocket motor(SRM),the flow field and thrust characteristics of scarfed nozzles with various angles was numerically simulated by using the unsteady compressible N-S equation,the Realizable k-εturbulence model and the hybrid grid technology.The results show that when the nozzle inlet uses an inclined installation form,there will be a certain mass flow loss for the scarfed nozzle motor,and the mass flow ratio is 0.938.The distributions of velocity fields at the axisymmetric parts of the throat and expansion section are basically the same for scarfed nozzles with various angles,whereas some unilateral phenomenon will be observed at asymmetric part of the nozzle expansion section.Increasing the scarfed angle from 45°to 90°,the axial thrust F x of the scarfed nozzle increases linearly,the lateral thrust F y decreases linearly,and the thrust deflection angle decreases from 2.323°to 0.063°,however,there is little influence on the mass flow and the total thrust.