论文部分内容阅读
基于横向槽结构和等离子体气动激励的新型流场调节方法,采用RNG k-ε湍流模型,数值计算分析了常规圆形孔、带横向槽以及带等离子体气动激励等不同气膜冷却结构的流场特性、温度场特性和冷却效率,揭示了等离子体激励器复合横向槽新型气膜冷却结构的冷却机理及规律。结果表明:圆形孔气膜冷却结构,气膜孔出流与主流混合强烈,在流场中形成了肾形涡对,冷流被逐渐抬离壁面,热流被卷吸到冷流下方,壁面的冷却效果最差;冷流经过等离子体激励器的气动激励后,产生了反肾形涡对,使得肾形涡对的平均涡量减小了42.64%,同时诱导冷流贴壁流动;横向槽的存在使得气膜孔出流在展向分布更宽,更贴近壁面,肾形涡对的强度较弱;在横向槽和等离子体气动激励的共同作用下,反肾形涡对的强度最大,使冷流的展向分布区域更大并贴近壁面流动。与圆形孔气膜冷却结构相比,在吹风比M=1.0下,带等离子体激励器、带横向槽和“等离子体激励器+横向槽”等三种气膜冷却结构的全局平均气膜冷却效率分别提高了181.6%,73.5%和200.5%。
Based on the new turbulence model of RNG k-ε based on the transverse flow cell structure and the new method of flow field adjustment of plasma aerodynamic stimuli, the numerical results of conventional circular holes, transverse grooves and gas-cooled cooling structures with plasma pneumatics Field characteristics, temperature field characteristics and cooling efficiency, revealed the cooling mechanism and rule of the new film cooling structure of the plasma actuator composite transverse groove. The results show that the round hole film cooling structure and the outflow of film hole are strongly mixed with the main stream, forming a kidney-shaped vortex pair in the flow field, the cold stream is gradually lifted off the wall, the heat flow is entrained below the cold stream, The cooling effect is the worst. When the cold flow is pneumatically excited by the plasma actuator, the anti-kidney-shaped vortex pair is generated, so that the average vorticity of the kidney-shaped vortex pair is reduced by 42.64%, and the cold flow adherent flow is induced at the same time. The existence of the groove makes the outflow of film hole spread more widely in the span direction and closer to the wall, and the strength of the kidney-shaped vortex pair is weaker. Under the combined action of the transverse groove and the plasma pneumatics, , So that the cold flow direction of the distribution area greater and close to the wall flow. Compared with the circular hole film cooling structure, the global average of the three film cooling structures with plasma exciter, lateral groove and “plasma exciter + transverse groove ” at the blow ratio M = 1.0 Film cooling efficiency increased by 181.6%, 73.5% and 200.5% respectively.