Multiobjective Constrained Optimization Procedure for Axial Flow Hydraulic Turbine Runner Design.

Abstract

This paper is concerned on the design optimization of axial flow hydraulic turbine runner blade geometry, and a new comprehensive performance Optimization procedure is presented by combining a multivariable multi-objective constrained optimization model with a Q3D inverse computation and a performance prediction procedure. The total hydraulic loss and the cavitation coefficient are taken as optimization objectives and a comprehensive objective function is defined using weight factors. Optimization variables are taken from parameters describing the blade bound circulation distribution and positions of the blade leading and trailing edges in the meridional flow passage. The optimization procedure has been applied to the design optimization of a Kaplan runner. Numerical results show that the performance of the designed runner is successfully improved through optimization computations. With the multi-objective optimization model, it is possible to control the performance of designed runner by adjusting the value of weight factors defining the comprehensive objective function.