扩压器叶片形线逆命题设计的一种新方法

A NEW INVERSE DESIGN METHOD OF DIFFUSER BLADES PROFILE

应用遗传算法结合神经网络技术通过对候选叶片表面速度分布与目标速度分布之间误差的极小化，求解给定表面速度分布下的扩压器叶片形线。叶片形线利用Ｂｅｚｉｅｒ曲线参数化表示，候选叶片形线的流场分析由ＢＰ神经网完成。所提出的方法用于一离心压缩机平行直壁扩压器的二元等厚叶片设计。

A genetic algorithm combined with a neural network technique is proposed to search for turbomachinery diffuser blade profile under the condition of a given velocity distribution on its surface.Such a new inverse method works through minimizing the error between surface velocity distribution of candidate blades and the target velocity distribution.For ease in employing genetic algorithm,the blade profiles searched are parameterized with Bezier spline curves.The flow analysis of the candidate blades is carried out by BP neural networks which have been trained with a set of samples.The proposed approach is demonstrated through the application to a diffuser with two-dimensional height-and thickness-constant blades.The simulations show that the new method is not only feasible,but also reliable and effective.