肋角度对流量系数影响的数值模拟研究

Numerical Investigation of Influence of Rib Orientation on Discharge Coefficients

利用有限体积法对三维不可压缩的N-S方程进行离散,对同时带肋和气膜孔出流的内流冷却通道在45°,60°,90°,120°肋的结构下进行了数值模拟。网格划分采用非结构化网格,湍流模型为Realizablek-ε模型,近壁处湍流采用壁面函数,采用SIMPLE算法求解速度与压力的耦合。计算获得了同时带肋和气膜孔出流的内流冷却通道在不同肋角度时的三维流场分布和气膜孔的流量系数值。结果表明同时带肋和气膜孔出流的通道流场结构比较复杂,肋在通道中诱发的二次流改变了气体在进入气膜孔时偏转角度,从而影响了流量系数值。通道中气膜孔的流量系数值随肋角度的增大而呈增大的趋势。计算结果与实验结果进行了比较,两者规律符合良好。

Numerical simulation was conducted to investigate the flow field of internal cooling passages with both rib-roughened walls and film hole suction and discharge coefficients of film holes, with rib angles 45°, 60°, 90°, 120° respectively. A finite volume method with unstructured meshes was used to solve the three dimensional incompressible Navier-Stokes equations. The realizable k-Ε turbulence model was used and standard wall function was used for near wall treatment. The coupling of velocity and pressure was performed using the SIMPLE algorithm. The numerical results show that the flow field of internal passages with both rib-roughened walls and film hole suction is a complex, secondary flow induced by ribs and changes the angles of the flow near the hole inlet and the hole axis, thus affects discharge coefficients. Discharge coefficients increase with the increase of rib angles. The calculated discharge coefficients are in good agreement with the experimental data.