带三角形突片气膜冷却结构换热特性的数值研究

运用RNG k-ε湍流模型对带平行于冷却壁面、且覆盖部分气膜孔的三角形突片气膜冷却结构,在不同吹风比和突片几何参数下的换热特性进行了研究.结果表明:在吹风比小于1时,突片对提高气膜冷却有效温比和增强换热的作用不大;当吹风比大于1时,突片对于提高气膜冷却的有效温比和换热增强比具有显著的作用,而且随着突片尺寸的加大,气膜冷却有效温比和换热增强比的提高幅度越大.

Numerical investigation on heat transfer of film cooling with delta-shaped tabs

Using method of constant heat flux,the heat transfer coefficient of the film cooling with a row of cylindrical holes and discrete delta-shaped tabs covering a part of the hole placed parallel to the film cooling surface was investigated numerically.The main factors influencing the heat transfer include the blowing ratio and the size of the tab.During the test,the mainstream velocity was 10 m/s and the blowing ratio was 0.3 to 1.5.Results show that the tabs do not enhance the heat transfer of the film cooling significantly at lower blowing ratio;heat transfer improvement is significant in the cases of higher blowing ratio with larger tab size.