小展弦比调节级三维多目标气动优化设计

3D Multi-Objective Aerodynamic Optimization Design for Low Aspect Ratio Governing Stage

大功率汽轮机调节级动叶是典型小展弦比叶片。动叶通道内上下通道涡交汇,流动呈现强烈的三维特性,其设计优化本质上是一个三维优化问题。结合自适应多目标差分进化算法、基于能量法的三维叶片造型方法和RANS方程求解技术,发展了轴流式叶栅三维多目标气动优化设计方法。利用该方法,完成了某典型大功率汽轮机调节级多目标气动优化设计。优化后小展弦比调节级气动性能明显提高,表明该方法具有良好的优化性能和应用前景。

The rotor blade of high power steam turbine governing stage is a typical low aspect ratio blade. The passage vortices near the upper and lower end wall encounter and mix with each other in blade passage, resulting a strong 3D character in the flow. Basically, the optimization design of it is a 3D optimization problem. On the combination of self-adaptive multi-objective differential evolution algorithm （SMODE）, 3D blade modelling method based on energy optimization and RANS solver technique, a 3D multi-objective aerodynamic optimization method for axial turbomachinery cascade design was developed. The governing stage of a typical high power steam turbine was optimized using this method. The optimal designs for the governing stage showed much better aerodynamic performance than that of the reference design. It demonstrates that the presented optimization method has good performance and shows a good prospect in the design for turbomachinery cascades.