多参数对叶顶气膜冷却的影响  

Multi-Parameter Influence on Film Cooling of Blade Tip

作　　者：韩昌[1] 任静[1] 蒋洪德[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《工程热物理学报》2012年第9期1501-1504,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学资金资助项目(No.51076076)

摘　　要：基于压力敏感漆(PSP)实验技术,本文研究了某F级重型燃机一级动叶平面叶顶和凹槽叶顶在不同冷却射流与主流质量流量比,不同密度比和不同叶顶间隙大小等多参数影响下的气膜冷却特性。平面叶顶冷却射流在气膜孔后往吸力面覆盖,凹槽叶顶在槽内形成回旋涡,冷却射流往压力面覆盖并向尾缘形成累积效应。平面叶顶和凹槽叶顶气膜冷却效率均随质量流量比的增大而增大。密度比增大,冷却射流出口动量减小,抑制了叶顶气膜垂直射流的吹离趋势,从而提高气膜冷却效果。叶顶间隙与叶顶形状、质量流量比等参数对气膜冷却效率有关联影响;间隙增大,气膜冷却效率在不同工况下的表现不同。另外凹槽叶顶的整体气膜冷却效果优于同等条件的平面叶顶。The tip film cooling characteristic of one-stage blade of some F-class gas turbine is investigated using pressure sensitive paint （PSP） in different conditions of mass flow ratio （MFR）, density ratio （DR） and tip clearance in this work. Cooling gas cover suction area on flat tip, but cover pressure area on squealer tip and format accumulated-effect to trailing edge because of the eddy produced in the squealer. The film cooling effectiveness of both flat tip and squealer tip increases as mass flow ratio increases. High density ratio decreases the exit momentum and constrains the lift-off of cooling ejection, so as to improve the film cooling effectiveness of blade tip. Tip clearance has relative influence with tip geometry and mass flow ratio, and film cooling effectiveness responses differently in different condition as tip clearance increases. Moreover, the integrate film cooling effect of squealer tip is better than that of flat tip.

关 键 词：质量流量比 密度比 叶顶间隙 压力敏感漆 气膜冷却 

分 类 号：TK123[动力工程及工程热物理—工程热物理]