多因素耦合影响亚音速喷口强化气体流场分布研究

Multi-Factor Coupling Effect of Subsonic Nozzle on Gas Flow Distribution

为了研究多因素耦合条件下亚音速喷口内气体流场分布演变的作用机制与影响规律,基于标准k-ε湍流模型,对压力-流速-收缩比耦合条件下的亚音速喷口构造均匀气体流场进行了数值模拟,通过定义top-hat流场分布关键参数的方式,定量评估压力-流速-收缩比对强化后流场分布的耦合影响。结果表明:多因素耦合条件下,亚音速喷口通过影响压力梯度平衡点与临界位置点在内的强化过程关键点改变强化流场分布的品质;提高气体压力可以有效减小构造流场中的边界层厚度,降低强化过程中关键点对流速的依赖,提升不同流速下边界层厚度的稳定性,收缩比的增加则会使得强化流场进一步偏离理想分布。

In order to study the interaction of gas flow field evolution in subsonic nozzle,the coupling effect of pressure-velocity-contraction ratio on the velocity profile was quantitatively evaluated. Based on the standard k-ε turbulence model,the numerical simulation was utilized for the uniform gas flow field in the subsonic nozzle under coupling effect and the key parameters of top-hat flow field distribution were defined. The results show that within multi-factor coupling,the subsonic nozzle can change the quality of the flow field distribution by influencing the key points of the strengthening process including the equilibrium point and the critical position point of the pressure gradient. Increasing the gas pressure can effectively reduce the boundary layer thickness in the tectonic flow field,reduce the dependence of the key points on the flow velocity in the process,and improve the stability of the boundary layer thickness under different flow velocities.The increase of contraction ratio leads to the further deviation of the flow field from the ideal distribution.