不同冲角下汽轮机拉筋气动损失系数的计算

Calculation of the Aerodynamic Loss Coefficient of the Lacing Wires in a Steam Turbine Under Different Attack Angles

采用Fluent软件对装有圆柱拉筋的平面叶栅进行了数值模拟,主要研究了圆柱拉筋引起的平面叶栅气动性能的变化以及叶片冲角对装有圆柱拉筋的平面叶栅的影响,计算了不同冲角下拉筋引起的损失系数,并与前人所做的实验结果吻合较好。结果表明:拉筋促使吸力面的流动分离加剧,使得吸力面附近的流动异常复杂。关于拉筋中心线形成上、下一个高损失涡对,在该处气流欠偏转;而在这个涡对中间的流体马赫数较高,气流呈过偏转。

By using software Fluent,a numerical simulation was performed of a plane cascade installed with cylindrical lacing wires.A change of the aerodynamic performance of the plane cascade arisen from the installation of cylindrical lacing wires and the influence of the attack angle of the blades on the plane cascade installed with the cylindrical lacing wires were mainly studied and the loss coefficients caused by the lacing wires under different attack angles,calculated.The calculation results were in relatively good agreement with the test ones obtained by the predecessors.The research results show that the lacing wires can exacerbate the flow separation on the suction surface and extremely complicated the flow near it.A high loss vortex pair is formed at the upper and lower portion relative to the centerline of the lacing wires,where the steam flow has an excessively low deflection angle.The fluid in the middle of the vortex pair has a relatively high mach number and assumes an excessively large deflection angle.