高性能透平叶片弯扭掠改型对流场影响

Effect of High Performance Turbine Blade Curved-Twisted-Swept Modification on Flow Field

为了探究在高负荷透平中叶片弯扭掠改型的适用性和差异性,本文以300 MW F级重型燃气轮机的透平末级为研究对象,采用正交优化和敏感性分析的方法,通过数值模拟的手段探究了弯、扭、掠单独变化对流场的影响。由于透平静叶改型对动静叶气动匹配有影响,因此本文对于每一种静叶改型都进行了与之气动最匹配的动叶扭转改型。研究得到了最佳静叶弯曲形式为两端反弯中部正弯,这种弯曲形式可以改善静叶端部的通流情况,削弱叶栅通道内的二次流强度,透平的轮周效率提升了0.86%。静叶扭转改型对透平影响较大,透平轮周效率提升了2%,但是透平流量系数下降较多,在使用扭转改型提升透平性能时需要关注扭角过大对透平性能带来的负面影响。相比于弯曲和扭转改型,静叶掠改型对透平的气动性能影响相对较弱。研究结果为高性能透平叶片设计提供了指导。

In order to explore the applicability and difference of blade bending,twisted and sweep modification in high-load turbines,this paper takes the last stage of the 300 MW F-class heavy-duty gas turbine as the research object,and uses orthogonal optimization and sensitivity analysis.The method explores the influence of bending,twisted and sweep on the flow field by means of numerical simulation.Due to the influence of turbine stator blade modification on the aerodynamic matching of the rotor and stator blades,this study investigates the aerodynamically best-matched rotor blade twist modification for each type of stator blade modification.The study shows that the best bending form of the stator blade is the reverse bending at both ends and the positive bending in the middle.This bending form can improve the flow condition at the end of the stator blade,weaken the secondary flow intensity in the cascade channel,and increase the turbine’s wheel efficiency by 0.86%.The twisted modification of the stator blade has a great influence on the turbine,and the turbine wheel efficiency is increased by 2%,but the turbine flow coefficient decreases more.When using the twisted modification to improve the turbine performance,it is necessary to pay attention to the negative impact of the excessive twisted angle on the turbine performance.Compared with the bending and twisted modification,the influence of the stator swept modification on the aerodynamic performance of the turbine is relatively weak.The research results provide guidance for the design of high performance turbine blades.