瞬态法测量高转速旋转盘表面传热系数

将实际发动机涡轮盘冷却系统简化为中心进气旋转盘,用瞬态实验的方法对该结构的换热特性进行了研究.以高转速旋转换热实验台为基础,建立了转静系盘腔中瞬态换热的实验流程和数据处理方法,得到了转盘表面的努塞尔数,并研究了流量系数、旋转雷诺数和出气间隙比对努塞尔数的影响.研究结果表明:对于中心进气冷却结构,在转盘低半径处,转盘表面的表面传热主要由冷气冲击控制,随着半径的的增大冲击对换热的影响减弱.转盘表面的努塞尔数随冷气流量系数的增大而增大,随旋转雷诺数的增大而增大,随出气间隙比的增大而减小. 

Transient measurement for measuring the heat transfer in a rotating cavity with a high rotational speed

A real turbine disk cooling configuration was simplified to be a shrouded rotating disk system with central coolant air.Heat transfer characteristic was studied by experimental method.On the heat transfer test rig with high rotating-speed for rotating components,the procedure of experiment and the method of data processing were established initially.The Nusselt number of the rotating disk surface was got,and the variations with the mass flow coefficient,the rotating Reynolds number and the ration of sealing clearance were studied.Conclusions could be drawn as follows:For central inlet,the heat transfer in the lower radius is mainly controlled by the impingement of cooling air,the influence of impingement decreases with the increasing of radius.The Nusselt number increases with the mass flow coefficient and the rotating Reynolds number,decreases with the ratio of sealing clearance.