交叉扭转椭圆气膜孔冷却机理研究  

Study on the Cooling Mechanism of Cross-Torsion Elliptical Film Hole

作　　者：肖坤 何娟 刘钊[1] 丰镇平[1] XIAO Kun;HE Juan;LIU Zhao;FENG Zhen-Ping(Institute of Turbomachinery,Shaanxi Engineering Laboratory of Tur bomachinery and Power Equipment,School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院叶轮机械研究所,陕西省叶轮机械及动力装备工程实验室,西安710049

出　　处：《工程热物理学报》2020年第11期2719-2725,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金面上项目(No.51876156)。

摘　　要：为改善高温叶片表面气膜冷却覆盖效果和提高气膜冷却效率,从抑制孔内喷射效应和流动分离出发,基于交叉扭转椭圆冷却通道内的反肾形涡涡系结构,提出了一种交叉扭转椭圆气膜孔。采用三维定常数值分析方法,对比研究了圆柱形气膜孔和交叉扭转椭圆气膜孔孔内流动结构、出口下游流场、温度场和气膜冷却效率,分析了不同吹风比下,气膜孔截面的交叉扭转对冷却特性的影响。结果表明:圆柱形气膜孔在孔内产生明显的喷射效应,冷气沿上风壁流动,并在出流后与主流相互作用形成较强肾形涡,使冷气抬离壁面,造成冷却效率降低;交叉扭转椭圆气膜孔对孔内喷射效应有较好的抑制作用,使气膜出流后能更好的贴附壁面,同时孔内产生的反肾形涡对出口下游肾形涡有一定的削减作用,从而进一步提高了冷却效率。其中,高吹风比下交叉扭转椭圆气膜孔对冷却效率的提升效果比低吹风比下显著;并且所有吹风比下,交叉扭转椭圆气膜孔总压损失均低于圆柱气膜孔。In order to improve the film coverage effect and film cooling effectiveness on the surface of high-temperature blades,a cross-torsion elliptical film hole was proposed based on the structure of anti-kidney-vortex in the cross-torsion elliptical cooling channel.The flow structures,downstream flow fields,temperature fields and film cooling effectivenesses of the cylindrical and cross-torsion elliptical holes were compared by using the 3 D steady numerical analysis method.The influence of cross-torsion of the cross section of the holes on the cooling characteristics was analyzed under different blowing ratios.The results show that the cylindrical film hole has obvious jet effect in the hole,the coolant flows along the upper wind wall,and it interacts with the main flow to form a strong kidney vortex,which makes the coolant lift away from the wall surface and reduces the cooling effectiveness;the cross-torsion elliptical film hole has a good inhibition effect on the jet effect in the hole,which makes the film adhere to the wall surface better after the coolant flows out.The effect of cross-torsion elliptical holes on cooling effectiveness is more significant under high blowing ratio than that of low blowing ratio.At all blowing ratios,the total pressure loss of cross-torsion elliptical hole is lower than that of cylindrical hole.

关 键 词：气膜冷却 交叉扭转椭圆孔 肾形涡 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程]