燃机叶片平行肋扰流内冷通道传热特性研究Part2:耦合传热特性

Heat Transferring of Channels With Repeated Ribs in Turbine Blades Part Ⅱ:Conjugate Heat Transfer Characteristics

平行肋扰流通道是高温透平叶片常用的冷却结构。本文通过批量(约1000次)的气热耦合数值计算对不同几何结构平行肋扰流冷却通道的流动与耦合传热特性进行研究.对于固定压差通道,存在使固体外壁温度最低的肋片布置形式及对应的最优冷气量,针对某重型燃机动叶设计了不同肋片角度的平行肋扰流冷却通道并进行了气热耦合数值计算,表明60°肋能在最小的冷气量下取得最强的换热,验证了机理研究的结论.

Rib-roughen cooling channels are widely used in turbine cooling. The flow and heat transferring characteristics of channels with various parallel rib-turbulators are investigated using about 1000 conjugate heat transfer simulations. For a rectangular channel under fixed pressure drop with solid walls, the optimum rib arrangement exists that gives the lowest average temperature on the outer wall, and the optimum coolant amount is achieved simultaneously. Rib-roughen cooling channels with different rib angles are designed for the ist stage rotor blade of a heavy duty gas turbine, and conjugate heat transfer simulations are performed. It is found that cooling channel with 60° rib angle has the best cooling performance and requires the least coolant, which validates former conclusions of the mechanism study.