论文部分内容阅读
以航空发动机涡轮叶片中段内部冷却通道为研究对象,将其简化为带肋变截面U型通道。对通道内有气膜出流时的换热特性进行了实验研究。实验模型中,矩形肋对称布置在上下2个表面,气膜孔仅布置在第2通道内。文中定义了气膜开孔率的概念,采用单元分析法研究了气膜开孔率和出流比对通道内单元努塞数分布和第2通道压力分布的影响。实验结果表明,气膜出流比一定时,随着开孔率的增加,换热增强;在两肋之间的3个气膜孔中,肋后孔对通道换热影响最大;气膜出流比与通道努塞数的关系为二次曲线。
Taking the cooling channel in the mid-section of the aero-engine turbine blade as the research object, it is simplified as a U-shaped channel with variable cross section. An experimental study on the heat transfer characteristics of the outflow of gas in the channel was carried out. In the experimental model, the rectangular ribs are symmetrically arranged on the two upper and lower surfaces, and the film holes are arranged only in the second channel. In this paper, the concept of the film porosity is defined. The influence of the film porosity and the outflow ratio on the Nusselt number distribution and the second channel pressure distribution in the channel is studied by elemental analysis method. The experimental results show that the heat transfer is enhanced with the increasing of the opening ratio when the film outlet ratio is constant. Among the three film holes between the ribs, the rib posterior orifice has the greatest influence on the channel heat transfer. The relationship between the flow ratio and the Nusselt number is a quadratic curve.