单腔内冷涡轮的气热耦合数值仿真

Coupled heat transfer simulations of an air-cooled turbine with single cooling channel

将所开发的HIT-3D气热耦合求解器应用于某低压涡轮的数值仿真中,对该涡轮设计简单的内冷结构,比较了不同湍流、转捩模型对叶片温度场预测的影响,初步验证了所开发的耦合求解器的应用能力.由于目前涡轮的冷却结构复杂,数值计算量比较大,为此发展了一种气热耦合与工程设计相结合的方法,以该涡轮为算例初步验证了该方法,并初步模拟了粗糙内壁面对叶片热负荷的影响.计算表明:在层流、转捩流动区域,采用全湍流模型预测的温度要比采用转捩模型的高,同时所发展的气热耦合与工程方法是可行的,可以极大地减少设计中的计算量.

The developed coupled solver HIT-3D was applied to the coupled heat transfer simulations of an air-cooled turbine with single cooling channel.Different turbulence and transition models were utilized.The numerical results validated the ability of the developed solver in the engineering simulation.Then a method combining the coupled heat transfer and engineering design techniques was developed to reduce the computational loads of simulations of turbines with complex cooling systems.With the same test case mentioned above,such method was validated,and the influences of rough inner wall on the blade thermal load were investigated.The results show that the transition model predicts lower vane thermal load than the full turbulence models at the transition zones on the vane surface,and that the developed method can greatly reduce the computational load during the turbine design.