基于优化技术的叶型反方法改进设计

Turbomachinery Profile Design by an Improved Inverse Method Based on Optimization Technique

在势流函数反方法设计叶型的过程中,通过分析叶片表面速度分布对叶型形状的影响规律,发现采用局部区域速度分布调整,可有效的克服以往反方法设计叶型中易出现的非物理解现象,并针对叶型前缘和尾缘的几何封闭问题分别建立了优化目标函数,借助流场求解中的优化迭代技术获得了具有良好气动性能并满足几何约束的叶型设计结果。对典型叶型的三个设计算例表明:所研究的叶型反问题优化设计方法,具有设计精度较高,适用范围较宽,工程应用性较好等优点。

It is very important for gas turbine engineers to have better blade design method, especially for axial flow turbomachinery with high pressure ratio, and to increase mass flow rate. Based on the potential-stream function inverse method, a design method is proposed. By investigating the influence of prescribed velocity coefficient distribution on blade surface, it is found that the non-physical solution usually obtained by general inverse method could be avoided by adjusting the local velocity coefficient distribution. The object functions are set up for leading edge closing and trailing edge closing problems respectively for numerical optimization. The optimized blade profiles with satisfactory performance and reasonable geometrical shape can be obtained by this improved optimization method. Three examples of profile design give good results in terms of design precision, and wider application areas in turbine and compressor blade profile design could be developed.