固体火箭发动机内气粒两相流动的SPH-FVM耦合方法数值模拟

Numerical Simulation of Gas-Particle Two-Phase Flow in SRM with SPH-FVM Coupled Method

关键词:  固体火箭发动机  气粒两相流  SPH  FVM  耦合方法

Key words:  Solid rocket motor  Gas-particle two-phase flow  Smoothed particle hydrodynamics  Finite volume fraction  Coupled method

摘要:

为解决现有数值模型在求解固体火箭发动机内颗粒的燃烧流动等问题时所遇到的难题，基于拟流体模型，采用光滑粒子流体动力学方法(SPH)求解离散颗粒相，追踪颗粒运动轨迹，采用有限体积方法(FVM)对气体连续相进行描述，捕捉流场特性，两相间通过曳力、压力梯度、热传导、体积分数等参量进行耦合，建立了两种不同坐标系下方法间的耦合框架。耦合方法模拟了喷气推进实验室(JPL)喷管中气粒两相流动过程，得到了气相和颗粒相的参数分布规律，与相关实验结果及离散颗粒模型(DPM)数值模拟结果对比，吻合较好。针对[?315mm]实验发动机工作状态和结构特点，进行了发动机燃烧室内过载条件下的气粒两相流动数值模拟，分析了纵、横加速度载荷对发动机燃烧室内粒子场和聚集带的影响，与已有的数值模拟结果基本吻合。结果表明，新方法求解发动机气粒两相流问题准确可靠，适用于发动机内更为复杂的两相流问题数值模拟。

Abstract:

To deal with the problems encountered in solving the particle combustion and flow with the existing models in Solid Rocket Motor(SRM)，smoothed particle hydrodynamics was used to solve the discrete particle phase and to trace each particle based on pseudo fluid model. The continuum gas phase was described by the finite volume method and the flow field characteristics were captured with this method. The two methods were coupled by drag force，pressure gradient value，heat transfer and the volume fraction. The coupling framework under two different coordinate systems was established. The gas-particle two-phase flow in Jet Propulsion Laboratory nozzle was solved by the new method. The parameters distribution of both gas and particle phases was obtained. The results were consistent with related experimental results and discrete particle model simulation results. Aiming at working conditions and configuration characteristics of[?315mm]motor，gas-particle two-phase flow in the chamber of motor under high acceleration was simulated. The effects of horizontal and vertical accelerations on particle field and accumulation zone were analyzed. The results agreed well with other simulation results. It shows that the method is accurate and reliable in solving the gas-particle two-phase flow in SRM and it may be applied in more complicated two-phase flow problems in SRM.