固体火箭发动机喷管扩散段破损流场仿真研究

Numerical Study of Damaged Flow Field In The Nozzle Diffusion Section Of Solid Rocket Motor

摘要:

为获取某型带长尾管的固体火箭发动机在工作过程中扩散段不同破损程度对其性能影响规律和影响机理，采用CFD方法对其进行建模仿真分析，通过对比不同破损程度下的流场分布和推力变化，揭示了该型发动机喷管扩散段破损对其流场和性能的影响规律；研究发现，气体从缺口处流出部分在轴向截面上基本呈扇形，在扇形弧线和半径相交处存在角结构；流场等值面可以划分为缺口处等值面、非缺口处等值面和两者之间相互作用等值面三部分；喷管在扩散段端口破损后会对下游流场产生影响，对上游流场影响非常小；随着扩散段端部缺口的增大，喷管推力方向与喷管轴线夹角逐渐增大。

Abstract:

In order to obtain the impact law and mechanism of different degrees of damage in the diffusion section of a certain type of solid rocket motor with a long tail pipe on its performance during operation, CFD method was used to model and simulate it. By comparing the flow field distribution and thrust changes under different degrees of damage, the impact law of nozzle diffusion section damage on the flow field and performance of this type of engine was revealed; Studies have found that the outflow of gas from the gap is basically fan-shaped in the axial section, and there is an angular structure at the intersection of the fan-shaped arc and radius. The isosurface of the flow field can be divided into three parts: the isosurface of the gap, the isosurface of the non-gap and the isosurface of the interaction between them. When the nozzle is damaged in the diffusion section, the downstream flow field will be affected, and the upstream flow field will be very small. With the increase of the gap at the end of the diffusion section, the angle between the thrust direction and the nozzle axis increases continuously.