气氢亚燃冲压燃烧室三维流场计算

Numerical Modeling of 3-D Reacting Flow Fields in Gaseous Hydrogen Ramjet Combustor

采用数值计算方法模拟气氢冲压模型燃烧室流场。文中采用 k- ε模型描述紊流特性 ,Magnussen的 EDC模型估算化学反应速率 ,六通量辐射模型考虑热辐射对燃烧过程的影响。采用非均匀交错网格系统 ,控制容积法和混合差分格式 ,离散控制方程 ,并应用 SIMPL E算法求解。在冷热态流场计算基础上 ,研究了不同来流空气和燃料氢各气流参数以及喷氢孔直径 ,孔数和孔间距对燃烧室出口温度分布 ,温升效率以及总压恢复系数的影响 ,结果令人满意 。

A three dimensional computer code is developed for simulating reacting flow fields of a gaseous hydrogen ramjet combustor. The k ε turbulent model is adopted to describe the influence of turbulence. The EDC turbulent combustion model is used to determine the rate of reaction. The six flux method is applied to predict the distributions of heat flux. To obtain the finite difference equations, the governing equations are intergrated by the hybrid scheme over the control volume. The SIMPLE solution procedure is used for flow calculations. A fully staggered grid system is adopted for the velocity components and the scalar. The wall regions are treated using the wall function approach and normal pressure gradient at the wall assumed to be zero is used. Symmetry conditions are imposed along the hydrogen injector centerline and only half of the interior domain is used in order to reduce grid requirement and computation time. Predictions show that the size and number of holes have an effect on the elevated temperature efficiency and total pressure loss.