冷却流量变化对叶栅冷却效果影响的数值模拟

采用气流流场与叶栅温度场耦合求解的数值模拟方法,研究了涡轮冷却叶栅前缘附近有冲击冷却结构时冷却流量变化对叶栅冷却效果的影响。计算结果表明:冷却流量增大,冷却气流射入主流场的穿透能力增强,在卵形涡对的诱导下,高温燃气绕过冷却气体并包围住了冷却气流核心区域,使其远离壁面。同时,冷却气体与主流相互作用发生掺混的能力增强,温度很快升高,对叶栅壁面的气膜保护作用降低;冷却流量增大,主冷却腔和冲击冷却腔内部流速增大,换热效应增强,内壁面冷却气流带走的热量加大。

Numerical simulation on the effect of variety of cooling flux on cooling efficiency

Conjugate heat transfer methodology was employed to study the effect of variety of cooling flux on cooling efficiency of vane near the turbine vane leading edge with impingement cooling configuration.The results indicate that the penetrating of the cooling flow into the main flow is improved.High temperature gas moves round cooling gas and circles its core.This makes it far from the wall.Meanwhile the cooling air mixes with main flow.As temperature of cooling air increases,the effect of the film protection depresses.By mean of increasing the cooling flux,the gas velocity of the main cooling cave and impingement cave increases.Thus,the efficiency of heat transfer increases and the heat amount brought away by cooling flow turns to be large.