某小型发动机环形回流燃烧室流场的数值计算

NUMERICAL CALCULATION OF FLOWFIELD INSIDE A SMALL ENGINE ANNULAR REVERSE-FLOW COMBUSTOR

采用数值模拟方法对某小型发动机回流燃烧室流场进行了计算和分析，用双方程ｋ－ε模型描述紊流特性，用二步化学反应模型模拟化学反应，并对复杂的边界条件进行了特殊处理。计算结果表明火焰筒主燃区形成了强烈的单涡回流，沿圆周方向主燃区速度场比较相似；在油雾场和速度场之间有较好的匹配，燃烧室有较好的性能。计算结果体现了回流燃烧室流场与直流燃烧室流场的较大差别。

Calculations of flow field with fuel injection and heat release inside an annular reverse-flow combustor of a small aeroengine have been performed with a 3-D elliptic turbulent reacting thermo-aerodynamic software.In the program the turbulence is simulated by the k-ε two-equations model,the combustion after vaporization is determined by a two-step chemical reaction model,the reaction rate is calculated with Arrhenius and eddy breakup model.The SIMPLE algorithm is used to solve the finite-difference equations.The complex boundary conditions are treated particularly.Predictions of gas temperature,velocity,and fuel/air ratio show that a strong vortex emerges in the primary zone of liner;the velocity circumferential distributions have a similarity;the combustor performance is satisfactory due to favourable matching between velocity and fuel/air ratio distributions.The small circumferential velocities contribute to a reasonalble velocity distribution at turbine stator.