采用数值模拟对比研究了光滑表面和具有表面凸起结构热气防冰腔内湍流流动的换热特性。机翼防冰腔内笛形管具有三排射流孔,射流孔角度有0°±45°组合以及0°±30°组合。为了强化射流冲击光滑表面的流动换热,在防冰腔内表面正对射流孔的射流冲击区,设计了表面凸起结构,用来强化射流对壁面的冲击换热效果并起到引流作用。通过改变射流孔射流角度研究了射流角度对传热特性的影响。计算结果表明:与光滑防冰腔内表面射流冲击换热相比,表面凸起结构可以将均匀发散的壁面射流集中为高速壁面射流,提高壁面射流区的对流换热系数,从而增强射流冲击换热效果,机翼前缘的强化换热效果尤为明显。
A comparative study is conducted to investigate the heat transfer characteristic of turbulent flow in the hot air antiicing system with and without surface convex by using numerical simulation method.Three-row impingement jet holes are set on the piccolo tube,with different impinging angles:0°±45°and 0°±30°.In order to strengthen the impinging heat transfer,the surface protrusions located in front of the impinging holes are designed as a guiding passage of the hot air.The influence of jet angle on heat transfer characteristics is studied by changing the angle of the jet.Calculation results show that the surface structures can enable the wall jet flow dispersing uniformly to be concentrated into wall jet flow with higher speed.Compared to the jet impingement heat transfer of anti-icing cavity with smooth surface,the convective heat transfer of the wall jet zone is enhanced.The heat transfer of jet impingement,especially on the wing leading edge,is thus increased.