导叶安装角变化对变几何涡轮性能影响的数值研究

The influence of stagger angle variation of guide vane on variable geometry turbine performance

为研究变几何涡轮导叶安装角变化对涡轮性能的影响,在传统定几何涡轮基础上,采用数值模拟方法对不同导叶安装角下涡轮导叶与动叶流场结构、出口参数、涡轮进口流量及效率进行了分析。结果表明:调整导叶安装角,可有效改变涡轮的通流能力,实现对涡轮流量的调节。针对所研究的小流量涡轮,导叶安装角转动1°,涡轮流量变化5%左右。安装角增大或减小幅度较大时都会引起动叶气流发生分离,导致涡轮效率下降,安装角减小时对效率影响更大;动叶负攻角设计可以提高涡轮的攻角适应性。

In order to study the influence of the variation of the stagger angle of the variable geometry turbine vane on the turbine performance,based on the traditional turbine,the numerical simulation technology was used to analyze the flow field structure and exit parameters of turbine vane and rotor with different vane stagger angles,turbine inlet flow and efficiency.The results show that adjusting the guide vane stagger angle can effectively change the flow capacity of the turbine to regulate the turbine flow.The guide vane stagger angle is rotated by 1°,and the turbine flow rate is changed by about 5%.No matter increasing or decreasing the stagger angle may cause the separation on surface of the rotor blade,which could reduce the turbine efficiency.When the stagger angle of guide vane decreases,it has a greater impact on the efficiency.Therefore,the design of negative incidence of the rotor could improve the adaptability of incidence of turbine.