Commercial CFD software package is used to simulate the flow field in a variable nozzle tur-bine. Experimental study was performed on a turbine characteristic test bench. The working conditions obtained in experiments were taken as the boundary conditions for CFD simulations. CFD results are also val-idated through experiments. The model was used to simulate the working conditions of turbine-engine matching. The pressure distribution on the vanes under different representative engine working conditions was calculated, and it is used subsequently to derive the torque of pneumatic force acting on the vanes. CFD results showed that the direction of pneumatic torque would change as working conditions of internal combustion engine were changed, leading to the discontinuity of turbine characteristic, and this should be avoided in maintaining stable engine operation. An effective method was carried out to optimize the posi-tion of the vanes' pin and improve the force status of the nozzle guide vane.%利用某可调涡轮特性试验的进出口参数作为边界条件,对其进行了数值模拟计算;以试验结果作为依据对模拟计算进行校核验证.在此基础上,对与该涡轮匹配的发动机若干典型工况下的可调涡轮进行了模拟计算,得出不同工况下涡轮喷嘴环叶片上所受的气动转矩.数值计算结果表明,喷嘴环气动转矩在发动机工况发生变化时,其方向会发生改变,这将导致涡轮特性的突变,不利于发动机的稳定工作.为了避免这种情况的发生,提出了一套旨在改善喷嘴环受力状态的喷嘴叶片转轴位置优化设计方法.
展开▼
