双层壳型冲击/气膜综合流量系数实验研究

Experimental Investigations on the Discharge Coefficient of Double-DeckerJet Impingement/Film Structures

关键词:  航空、航天推进系统  双层壳型  冲击/气膜冷却  流量系数

Key words:  Aero space propulsion system  Double-decker  Jet impingement/film cooling  Discharge coefficient

摘要:

为了研究新型高效涡轮铸冷叶片内部冷却通道中的流动特性,以铸冷叶片典型结构——双层壳型冲击/气膜复合冷却结构的平壁模型为研究对象,实验研究了该种冷却结构的综合流量系数C_d随冲击雷诺数Red (600~2800) ,主次流吹风比M (0.7~7),冲击间距比H/d(0.5~1.25),冲击孔和气膜孔间距比 P/d(0,3,4)等参数的变化规律。研究结果表明:(1) C_d随着冲击雷诺数Red,吹风比M的增加而增大,在吹风比小于3工况下更为显著；(2) 在相同的气动参数条件下,综合流量系数C_d随着孔排距比P/d的增加而增大, 随着冲击间距比H/d的减小而显著降低。 

Abstract:

To obtain the flow characteristics of new type high efficient castcool cooling turbine blade, experiments were carried out to investigate the discharge coefficient C_d of the typical structure, the lamellar double-decker jet impingement or film structures. In experiments,the parameters such as the Reynolds number Red (600 ~2800), blowing rate M(0.7~7), the ratio of the jet impingement distance to the diameter of the jet holes H/d(0.5~1.25), and the ratio of the distance between jet hole and film hole to the diameter of the jet holes P/d (0,3,4) were varied, and the rules of C_d were concluded. The Experimental results show that, (1) C_d increases with increasing the impingement Reynolds number Red and the blowing rate M especially when M is smaller than 3.(2) C_d increases with P/d increasing, and decreases significantly with H/d reducing.