旋转状态气膜换热机理的数值研究  

Numerical simulation of heat transfer physics of film cooling under rotating conditions

作　　者：刘宁[1] 孙纪宁[1] 

机构地区：[1]北京航空航天大学能源与动力工程学院航空发动机气动热力国家级重点实验室,北京100191

出　　处：《航空动力学报》2011年第4期836-841,共6页Journal of Aerospace Power

摘　　要：大涡模拟研究了旋转对单孔平板气膜冷却的影响,气膜出流的雷诺数为2600,吹风比为0.5,计算了静止和旋转数为0.02两种状态的流动和换热,从湍流结构演化的角度讨论了旋转状态气膜换热的机理.结果表明:①发卡涡是决定气膜换热的主要湍流结构,旋转状态发卡涡的形状和运动规律主要受哥氏力的影响;②气膜在哥氏力作用下向高半径方向偏移,弱化了射流前缘与主流的剪切和掺混,使气膜保持较低温度;③气膜的侧向速度诱发垂直向下的哥氏力,压制射流贴附壁面,并降低对转涡对的强度,减少了对主流的卷吸,增强了气膜的保护效果.Large eddy simulation was used to investigate the effect of rotation on film cooling over flat plate with single hole.The Reynolds number at the jet exit was 2 600,and the blowing ratio was 0.5.The flow and heat transfer without rotation and with rotating number of 0.02 were calculated,and the heat transfer mechanics under rotating condition was analyzed through the evolvement of turbulence structure.It was found that hairpin structure determined the heat transfer of film cooling,and the shape and trajectory of hairpin structure was mainly affected by Coriolis force under rotating condition.The film was driven towards high radius side by spanwise Coriolis force,resulting in less mixing between main flow and jet and maintaining low temperature of the film.The Coriolis force normal to the wall reinforced the film attachment and reduced the strength of counter rotating vortex pair,leading to less entrainment of mainflow and better coverage of film.

关 键 词：气膜冷却 大涡模拟 旋转状态 哥氏力 湍流结构 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]