交叉扭转椭圆冷却通道流动和换热研究

Study on Flow and Heat Transfer in Cross-Torsion Elliptical Cooling Channel

本文基于场协同理论,提出了一种可用于燃气透平叶片内部冷却的交叉扭转椭圆形截面内部冷却通道,其基本原理在于通过椭圆形截面通道的交叉扭转,能够实现纵向二次涡的产生,从而强化透平叶片的内部冷却。结合Fluent软件,对该通道内的流动阻力和换热特性进行了计算,并在此基础上分析了交叉扭转角度和长短轴长度比对通道内部流动和换热特性的影响。结果表明:交叉扭转椭圆截面通道使内部冷却显著强化,而流阻增加较少,计算工况下同功耗下的强化换热指标可达1.5;通道的最佳扭转角度范围宽广,实际应用中交叉扭转角度可以在45°~90°之间灵活选取;通道截面的最佳长短轴长度比为1.3~1.5。

Based on the Field-Coordination Principle,a cross-torsion elliptical cross-section internal cooling channel for gas turbine blades is proposed in this paper.Its basic principle is that the secondary longitudinal vortices can be generated by cross-torsion of elliptical cross-section channel,thus enhancing the internal cooling of turbine blades.Combining with Fluent software,the flow resistance and heat transfer characteristics in the channel are calculated,and the effects of cross-torsion angle and length ratio of long axis to the short axis on the flow and heat transfer in the channel are analyzed.The results show that the cross-torsion elliptical cross-section channel can significantly enhance the internal cooling,but the flow resistance increases less,and the heat transfer enhancement index can reach 1.5 under the same power consumption;the range of optimal cross-torsion angle of the channel is wide,and the cross-torsion angle can be flexibly selected between 45~90 degrees in practical application;and the optimal length ratio of long axis to the short axis of the channel cross-section is between 1.3~1.5.