叶片前缘两相流冲击冷却的耦合数值模拟

Conjugate Simulation of Two Phase Flow Impingement Cooling on Blade Leading Edge

为了更好地强化叶片前缘的换热,对叶片前缘进行两相流强化冲击冷却的耦合数值模拟研究。利用水滴/蒸汽冲击曲面冷却系统进行数值模拟程序的校核。在此基础上,利用欧拉-拉格朗日颗粒追踪方法对叶片前缘的两相流冲击冷却进行耦合数值研究。研究了水滴加湿量、水滴直径和水滴与壁面的作用边界条件对换热性能的影响。结果表明当加湿量从3%增加到8%时,最大的平均传热增强系数从1.671增加到4.913;水滴直径从5μm增加到20μm时,最大的平均传热增强系数从2.128降低到1.164;反弹和反弹+破碎边界条件预测的传热效果好于粘附和粘附+破碎边界条件。

Conjugate simulations for the blade leading edge of two phase impingent cooling were carried out to enhance the heat transfer. The mist/steam cooling with jet impingement onto a concave surface was used to veri- fy the accuracy of numerical simulation program. The Eulerian-Lagrangian particle tracking method was adopted to investigate the two-phase impingement cooling for blade leading edge. The effects of various parameters, such as mist ratio, mist diameter and mist-wall boundary conditions on the improvement of cooling performance were investigated. The results show that the largest average heat transfer enhancement coefficient increases from 1.67 to 4.94 with increasing mist ratio from 3% to 8%, and it decreases from 2.128 to 1.164 with increasing mist diameter from 5μm to 20μm. The rebound and rebound with break up boundary conditions show the better cooling performance than the trap and trap with break up boundary conditions.