吹风比对涡轮叶片尾缘气膜冷却效率影响  

Effect of blowing ratio on film cooling efficiency of trailing edge on turbine blade

作　　者：李广超 于全朋 张魏 寇志海 LI Guangchao;YU Quanpeng;ZHANG Wei;KOU Zhihai(Faculty of Aerospace Engineering,Shenyang Aerospace University,Shenyang 110136,China)

机构地区：[1]沈阳航空航天大学航空航天工程学部(院),辽宁沈阳110136

出　　处：《热力发电》2018年第10期58-65,共8页Thermal Power Generation

基　　金：国家自然科学基金项目(51406124);辽宁省自然科学基金项目(201602576)~~

摘　　要：为了探索涡轮叶片尾缘劈缝冷却特性,针对后台阶三维劈缝冷却模型,采用数值模拟方法研究了吹风比Br=0.5、0.8、1.0、1.5时的气膜冷却效率。结果表明:后台阶区域劈缝下游气膜冷却效率比肋下游气膜冷却效率在小吹风比(Br=0.5)时高10.9%～39.1%,在大吹风比(Br=1.5)时高53.5%～56.0%;Br越大,后台阶气膜冷却效率沿流向降低速度越快,后台阶尾部气膜冷却效率沿半圆柱周长方向降低速度越慢;肋下游后台阶尾部,Br为0.8和1.0时气膜冷却效率比Br为0.5和1.5时高7.0%左右;后台阶尾部是气膜冷却的薄弱部位,其面积加权平均气膜冷却效率比后台阶低37.0%～39.0%;Br为0.8、1.0时,后台阶及其尾部的面积加权平均气膜冷却效率最高,较Br=0.5时高9.0%～11.0%,较Br=1.5时高3.0%～6.0%。In order to investigate the cooling characteristics of the trailing edge on turbine blade,numerical simulation method was used to study the film cooling effectiveness at the blowing ratios of 0.5,0.8,1.0 and 1.5 for the three-dimensional split cooling model of the backward-facing step.The results show that,in the backward-facing step area,the film cooling effectiveness in the downstream of the split slot is 10.9%~39.1%higher than that of the ribs at small blowing ratio of 0.5 and 53.5%~56.0%higher at big blowing ratio of 1.5.The higher the blowing ratio is,the faster the film cooling effectiveness of the backward-facing step decreases along the gas flow direction,and the lower the film cooling effectiveness of the tail of backward-facing step decreases along the direction of the semi-cylindrical circumference.On the downstream of the tail ribs of backward-facing step,the film cooling effectiveness of blowing ratio of 0.8 and 1.0 are about 7.0%higher than that of 0.5 and 1.5.The backward-facing step tail is the weak part of the film cooling,and its area-weighted average film cooling effectiveness is 37.0%~39.0%lower than that of the backward-facing step.When the blowing ratio is 0.8 and 1.0,the area-weighted average film cooling effectiveness of the backward-facing step and its tail is the highest,which is 9.0%~11.0%higher than that of the blowing ratio of 0.5,and 3.0%~6.0%higher than that of the blowing ratio of 1.5.

关 键 词：吹风比 燃气轮机 涡轮 叶片 尾缘劈缝 后台阶 气膜冷却效率 数值模拟 

分 类 号：TK47[动力工程及工程热物理—动力机械及工程]