三维贴体坐标系下燃烧室热态流场的大涡模拟

Large-eddy simulation of turbulent reacting flows in the combustor by three-dimensional body-fitted grid

关键词:  航空发动机  燃烧室  贴体网格+  大涡模拟+  流动分布

Key words:  Aircraft engine  Combustion chamber  Body-fitted grid  Large-eddy simulation  Flow distribution

摘要:

大涡模拟三维贴体坐标系下环形燃烧室火焰筒热态紊流瞬态流场。利用椭圆方程方法生成三维贴体网格,计算中采用k方程亚网格尺度模型估算亚网格紊流粘性;亚网格EBU燃烧模型估算化学反应速率;热通量辐射模型估算辐射通量。并在非交错网格系下采用SIMPLE算法和混合差分格式求解离散方程,利用壁面函数处理固壁边界条件。计算结果与实验结果的比较表明,采用大涡模拟方法能更真实反映环形燃烧室火焰筒内紊流化学反应流气流结构和燃烧过程。

Abstract:

Turbulent chemical reacting transient flows in the annular combustor were studied by the large-eddy simulation (LES). Three-dimensional body-fitted grid was generated by an elliptical grid generation procedure. In the large-eddy simulation, the k-equation sub-grid scale model was used to simulate the sub-grid eddy viscosity. The EBU combustion sub-grid scale model was employed to determine the chemical reaction rate. The heat flux model was applied to prediction of the heat flux. SIMPLE algorithm and hybrid scheme were used. Wall function was applied to treating near wall region. Comparisons between simulation results and measurements show the large-eddy simulation method with body-fitted grid may be used to investigate chemical reacting flows and combustion process in combustors.