双向扩张孔出口宽度对气膜冷却特性影响  

Effects of Exit Width on Film Cooling Characteristics of Dual-Fanned Holes

作　　者：李广超[1] 付建[2] 张魏[1,3] 寇志海[1] 

机构地区：[1]沈阳航空航天大学航空航天工程学部辽宁省航空推进系统先进测试技术重点实验室,辽宁沈阳110136 [2]北京航空航天大学能源与动力工程学院,北京100191 [3]西北工业大学动力与能源学院,陕西西安710072

出　　处：《推进技术》2016年第11期2088-2096,共9页Journal of Propulsion Technology

基　　金：国家自然科学基金(51306126);航空科学基金(2012ZB54006);辽宁省自然科学基金(2015020112)

摘　　要：采用窄带液晶瞬态测温技术,研究了圆柱孔和不同出口宽度双向扩张孔气膜冷却特性。主流雷诺数为6500,吹风比为1.0和2.0。双向扩张孔入口宽度为1.5倍孔径,出口宽度分别为1.5倍、2.0倍和2.5倍孔径。结果表明:吹风比为1.0时,出口宽度对气膜冷却效率和换热系数二维分布影响较小。吹风比2.0时,增加出口宽度不仅改变了气膜冷却效率和换热系数分布,还增大了径向平均冷却效率值,减小了径向平均换热系数值。双向扩张孔出口宽度增大到2.5倍孔径时,面平均冷却效率较圆柱孔增加118.2%,面平均换热系数降低14.3%。吹风比为2.0时,与圆柱孔相比,出口宽度增加逐渐改变了气膜冷却效率和换热系数二维分布。双向扩张孔出口宽度增大到2.5倍孔径时,面平均冷却效率增加了219.4%,面平均换热系数降低了27.2%。The film cooling characteristics of cylindrical hole and dual-fanned holes were studied by narrow band liquid crystal transient measurement technique at the mainstream Reynolds number of 6500 and the blowing ratios of 1.0 and 2.0,respectively. The entrance widths of dual-fanned holes were 1.5 times of the cylindrical diameter and the exit widths were 1.5,2.0 and 2.5 times of the cylindrical diameter（d）,respectively.The results show that the exit width has a weak influence on the two dimensional distribution of film cooling effectiveness and heat transfer coefficient at the blowing ratio of 1.0. The increases of exit width not only change the distribution of film cooling effectiveness and heat transfer coefficient,but also cause the increase of the spanwise averaged film cooling effectiveness and the decrease of the spanwise averaged heat transfer coefficient at the blowing ratio of 1.0. Since the exit width is expanded to 2.5d,compared with the cylindrical hole,the plane averaged film cooling effectiveness of the dual-fanned hole increases by 118.2% and the plane averaged heat transfer coefficient is decreased by 14.3%. At the blowing ratio of 2.0,by comparison of the cylindrical hole,the expansion of exit width changes the two dimensional distribution of film cooling effectiveness and heat transfer coefficient with the dual-fanned holes. The exit width is expanded to 2.5d,the plane averaged film cooling effectiveness of the dual-fanned hole increases by 219.4% and the plane averaged heat transfer coefficient is decreased by27.2%.

关 键 词：瞬态测量 热色液晶 图像处理 气膜冷却 冷却效率 换热系数 

分 类 号：V435.12[航空宇航科学与技术—航空宇航推进理论与工程]