多重网格加速的LUSGS算法用于喷管流场数值模拟

Numerical simulation for nozzle flow field based on LUSGS algorithm accelerated by multigrid

关键词:  LUSGS  多重网格+  刚性+  喷管  数值仿真

Key words:  LUSGS  Multigrid+  stiffness  Nozzle  Numerical simulation

摘要:

采用有限体积法,二阶精度插值的Roe格式对三维流场N-S方程进行空间离散;采用LUSGS隐式时间推进法和多重网格技术加快计算收敛速度;采用独特的显式算法克服了两方程湍流模型刚性对流场计算收敛速度的影响,并给出了该方法的理论依据。通过轴对称喷管内流场、二元喷管内外流场的数值模拟验证了采用以上方法在计算效率上的提高。最后将RNG模型计算结果与SA模型计算结果及实验数据做对比分析。

Abstract:

Finite volume method and second order Roe’s scheme are employed to spatially discretize three-dimensional N-S equation.LUSGS implicit temporal stepping method and multigrid technique are employed to accelerate convergent rate.An unique explicit algorithm is employed to overcome influence of two-equation turbulence model’s stiffness on convergent rate.And the theoretical derivation of the method is given.Internal flow field of an axisymmetric nozzle and internal-external flow field of a two-dimensional nozzle are simulated,to confirm the improvement of calculation efficiency by above methods.Finally,the calculation results from RNG and SA model are analyzed and compared with experimental data.