为使采用驻涡燃烧的旋转冲压发动机的燃烧组元获得燃烧的稳定性,研究后驻体喷孔位置对驻涡腔流动冷态数值的影响.应用Fluent软件模拟驻涡燃烧室中三维冷态流场的流动特性;湍流模型采用RNG k-ε模型,近壁面处采用标准壁面函数法;设置喷射物质为理想气体;控制方程离散采用基于控制体中心的有限体积方法,选用隐式二阶迎风格式;驻涡燃烧室三维几何模型采用结构化适体网格,网格节点单元数约为600 000;求解方程组采用动量方程和能量方程进行耦合的方法,控制残差〈10-4.结果表明:后驻体喷孔位置对驻涡腔的总压损失、喷射质量流率影响较小;随着喷射位置向后驻体外侧偏移,驻涡腔内的流场平均流速有所降低,形成有利于稳定火焰的流动条件.计算预测的变化趋势与实验结果相同,表明可为实际设计提供一种有效的方法.
In order to make the combustion component in rotation ramjet which uses trapped vortex combustion obtain combustion stability,the impact of nozzle position on after body on cold flow field values in trapped vortex chamber is studied.The software Fluent is used to simulate flow quality of the three-dimensional cold flow field in trapped vortex combustion chamber;RNG k-ε model is used as turbulence model and standard wall function method is used to simulate the flow near the wall;jet material is set as ideal gas;control equations are discretized by finite volume methods which are based on control of volume center,and second-order implicit upstream scheme is chosen;a structured body fitted grid is used for three-dimensional geometric model of trapped vortex combustion chamber,and the number of grid node unit is about 600 000;the method of coupling momentum and energy equations is used to solve equation set,and the residual is less than 10-4.The results show that the total pressure loss and the jet mass flow rate are less affected by the injection position on after body;the average velocity of the flow field in thetrapped vortex chamber decreases with the injection position moving outside of the after body,which creates favorable flow conditions for steadying the flame.The variation trend which is predicted by calculation is the same as that of experimental results,which indicates that this can be an effective method forpractical design.