考虑冷气掺混的涡轮气动性能数值研究

采用数值求解雷诺平均N-S方程的方法,数值模拟了带冷气掺混的涡轮内部全三维黏性流场,研究了冷气掺混对涡轮流动损失和气动性能的影响。数值计算结果表明,对于具有单排孔冷气入射的气膜冷却情况,当入射角是30°时,随着冷气流量增加,流动损失减小;而对于多排气膜孔冷气入射,各排气膜孔冷气之间的干扰是引起流动损失的主要原因,对不同位置冷气流量的优化选择,可以明显减小前后排冷气的掺混损失。为了降低冷气掺混的流动损失,基于数值实验的结果,本文首次引入了叶片表面气膜孔沿径向交错排列结构。

Numerical Simulation of the Aerodynamic Performance of Turbine with Coolant Injection

Detailed numerical simulations are performed to research the mechanics of the total pressure loss at the three-dimensional turbine flow field with coolant injection from single row of holes at the different directions and from all the rows of holes.The results show that the flow loss is reduced with the increasing of the coolant mass when the injection angle is 30° at the instant of injection from single row of holes.The interaction among the different rows of coolant injection is the major reason of the flow loss for the multi-rows film cooling.The further numerical investigations indicate that the optimizing election of coolant injection mass flow rate can reduce the total pressure loss apparently.It is shown that the interval rows of holes on the blade surface may be the best way to reduce the flow loss.