固体火箭喷管两相粘性跨音速流场计算

CALCULATION OF TWO-PHASE VISCOUS TRANSONIC FLOW FOR SPRM NOZZLE

关键词:  火箭发动机喷管  跨音速流  粘性流  流场计算

Key words:  Rocket engine nozzle  Transonic flow  Viscous flow  Flow field  Computation

摘要:

本文进行了固体火箭喷管两相粘性湍流跨音速流场计算.粘性的气相控制方程用隐式近似因子分解法求解,粒子方程采用跟踪粒子轨迹的特征线法求解,粘性湍流选用代数模型,气相和凝相充分地偶合.CFL数可以取500左右,收敛速度快,使粘性两相跨音速喷管流场计算耗费的机时达到工程计算可以接受的程度.通过计算,获得了在粘性和粒子同时作用下的流场参数分布.这对固体火箭发动机流场需要同时考虑粒子和粘性作用的专题研究大有裨益.

Abstract:

It is necessary to calculate the two-phase viscous transonic flow in a solid rocket nozzle.At present,explicit scheme is commonly used in calculation. And the consumption of computer time is not acceptable.So a practical calculation method in engineering is needed.The implicit scheme is attracting. Authors use implicit scheme to calculate the internal grid. Given that the CFL number is about 500.The convergen rate increases greatly. So the calculation can be performed on a personal computer. The consumption of computer time is acceptable for engineering calculaton. To do this,the calculation of inviscid, gas-phase, transonic nozzle flow is performed first by use of implicit approximation-factorization algorithm.Then viscous,gas-phase, transonic nozzle flow and inviscid, two-phase, transonic nozzle flow are performed respectively by use of the same algorithm. Based on the above-mentioned works, viscid, two-phase,transonic nozzle flow calculation is finally performed.In the calculation, the viscous, gas-phase governing equations are solved by implicit approximation-factorization algorithm,while particle equations by characterist ic following the tracks of particles, and gas-phase and particle-phase are fully coupled.Passing through the calculation, the parameter of nozzle flow are obtained under the effect of both particle and viscosity.In particular, the para-meters distributions in boundary layer are obtained.Particles produce greateffect for two-phase, viscid, turbulent core flow.Gas viscosity makes axial velocity to rapidly reduce to zero,and existence of particles make the velocity distribution to tend to gentleness. The particle content greater and its size smaller, the effect for flow parameters is greater.