加力燃烧室湍流火焰面模型优化方法

Optimization method of turbulent flamelet model in afterburner

加力燃烧室中流速高、压力低、含氧量低,燃油喷射以直射式为主,常用燃烧模型多会高估其反应速率。火焰面类模型采用查表法处理标量场,计算速度较快,但较难调整反应速率。在稳态层流火焰面模型基础上,添加了非定常化学动力学的影响因素来调整反应速率;在试验数据基础上,建立火焰面反应时间尺度,优化火焰面数据库,改善了该类方法在高速、低压、贫氧和雾化差下的数值仿真精度。结果表明:该优化方法形成的火焰面数据库能够较好模拟加力燃烧室中燃油复杂化学反应过程;在本文计算结果验证中,能将温度分布模拟误差控制在15%以内,平均温度模拟误差控制在5%以内。

In the afterburner with high flow rate high,low pressure,oxygen poverty,the direct fuel injection is predominent,and the combustion model usually overestimates the reaction rate of the afterburner.Table-searching method is used in flamelet models with the advantage of fast calculation,but it is difficult to adjust the reaction rate.Based on the steady laminar flamelet model,unsteady chemical kinetic factors were added to adjust the reaction rate.Based on the experimental data,the key geometric parameters were established.The flamelet database was optimized,and the numerical simulation accuracy of this method was improved under high speed,low pressure,oxygen poverty and poor atomization effect.The results showed that the flamelet database formed by this optimization method can better simulate the complex chemical reaction process in afterburner.According to the calculation results,the simulation error of temperature distribution can be controlled within 15%,and the simulation error of average temperature can be controlled within 5%.