喷管两相湍流数值模拟及湍流模型性能评估  

Numerical simulation of gas-particle flow in nozzle and evaluation of turbulence model performance

作　　者：陈良兵 廖紫默 刘难生[1] 万振华[1] CHEN Liangbing;LIAO Zimo;LIU Nansheng;WAN Zhenhua(University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学近代力学系,合肥230026

出　　处：《固体火箭技术》2024年第1期24-34,共11页Journal of Solid Rocket Technology

基　　金：燃烧、热结构与内流场重点实验室基金(No.6142701210204)。

摘　　要：研究固体火箭发动机喷管中颗粒质量流率对两相流的影响规律以及不同RANS模型对该问题的预测性能,可为喷管设计等工程应用提供重要参考。在欧拉-拉格朗日(Euler-Lagrange)框架下,通过3D大涡模拟(3D LES)研究了颗粒质量流率对喷管两相流场的影响规律,以3D LES结果作为参考依据,分析了不同RANS模型针对喷管两相流在2D轴对称和3D模拟中的性能。结果表明:由于扩张段内颗粒集中在中轴线附近区域,颗粒质量流率越大,该区域马赫数越低,温度越高;壁面附近存在无颗粒区,故边界层内流动几乎不受颗粒影响。另外,采用不同湍流模型计算得到的颗粒分布与LES基本相同。在2D轴对称RANS模拟中,发现RNG k-ε模型所预测的气相质量流率和喷管比冲与LES结果吻合最好;在高颗粒质量分数下(约30%),不同湍流模型预测的相对比冲损失差别可超过3%。在3D RANS模拟中,发现Realizable k-ε模型表现出最佳的综合性能,所预测的物理量沿中轴线分布的准确性均优于其他模型。当颗粒质量分数约为31.2%时,Realizable k-ε模型所预测的比冲为与LES结果相比误差仅1.56%。In order to provide a reference for engineering practice,it is necessary to understand the effect of particle mass flow rate in solid rocket motor(SRM)nozzles as well as the applicability of various RANS models for the simulation of two-phase flow in SRM nozzles.In this work,the effect of particle mass flow rate on the flow of SRM is investigated by 3D Large Eddy Simulation(3D LES)in the Euler-Lagrange framework,and the performance of various RANS models in 2D axisymmetric and 3D simulations,respectively,is evaluated by comparing with the 3D LES results.It is found that the particles in the expansion section are mainly concentrated in the central region leading to occurrence of lower Mach number and higher temperature there,and the flow in the boundary layer almost absent of particles is nearly unaffected.The particle distributions obtained by various RANS models compare basically the same as that by LES.For the 2D axisymmetric RANS simulation,the impulse and gas mass flow rate obtained by the RNG k-εmodel are found in best agreement with the LES results.Specifically,the difference in relative impulse loss predicted by different RANS models exceeds 3%at high particle mass fractions(~30%).For the 3D RANS simulation,the Realizable k-εmodel is found to have the best comprehensive performance,as the physical quantities along the central axis predicted by the Realizable k-εmodel is closer to the LES results.Specifically,when the particle mass fraction is about 31.2%,this model predicts a specific impulse of error 1.56%compared to the LES result.

关 键 词：固体火箭发动机 喷管 气粒两相流 湍流模型 欧拉-拉格朗日方法 

分 类 号：V435[航空宇航科学与技术—航空宇航推进理论与工程]