[关键词]
[摘要]
为提高涡轮叶片耐温能力,将蜂窝冷却通道应用于涡轮叶片内部,通过流热耦合计算研究蜂窝冷却通道叶片的传热流动特性。对蜂窝冷却通道的参数化方法进行研究,将蜂窝通道拆分成两种基本结构单元,即可方便调整蜂窝通道的几何参数;使用增材制造的叶片进行实验,通过对比数值计算与实验的冷却效率,验证了数值方法的准确性;在冷却二次流占比1%条件下,在原型蜂窝通道的基础上进行蜂窝通道空间布局和直径分布的调整,利用冷却效率、压降及相对阻力系数衡量不同通道的流动传热特性。研究表明:蜂窝通道由于增大换热面积以及增加分叉点强化换热,冷却效率提高到0.525,压降升高至229.1 kPa;通过调整蜂窝几何参数可以优化蜂窝通道的传热与阻力特性,通过增加蜂窝通道层数、增大次通道直径可以提高冷却效率,通过增加蜂窝通道入口数、增大主通道直径可以减小压降。
[Key word]
[Abstract]
In order to improve the ability of temperature resistance of turbine blades,the honeycomb cooling channel is applied to the interior of the turbine blade.The heat transfer and flow characteristics of the honeycomb cooling channel of blade are studied through the coupled fluentthermal calculation.The parameterization method of the honeycomb cooling channel is researched,and the geometric parameters of honeycomb channel can be easily adjusted by dividing it into two basic structural units;experiments are carried out using the additively manufactured blades,and the accuracy of the numerical method is validated by comparing cooling efficiency of experiment and numerical calculation;under the condition that the cooling secondary flow accounts for 1%,on the basis of the prototype honeycomb channel,the spatial layout and diameter distribution of the honeycomb channel are adjusted,and the flow heat transfer characteristics of different honeycomb channels are measured by using cooling efficiency,pressure drop and relative drag coefficient.Studies show that by virtue of larger heat transfer area and bifurcation points of the honeycomb channel to enhance heat transfer,the cooling efficiency is improved to 0.525,and the pressure drop is increased to 229.1 kPa;the heat transfer and resistance characteristics of the honeycomb channel can be optimized by adjusting the honeycomb geometric parameters,such as improving the cooling efficiency can be achieved by increasing the number of honeycomb channel layers and increasing the diameter of the secondary channel and reducing the pressure drop can be achieved by increasing the number of honeycomb channel inlets and increasing the diameter of the main channel.
[中图分类号]
TP183
[基金项目]
国家自然科学基金(52076128);国家重大专项基础研究项目(2017-I-0011-0012)