Rotor Blade Geometry Optimisation in Kaplan Turbine

Marzena Banaszek; Krzysztof Tesch

Rotor Blade Geometry Optimisation in Kaplan Turbine

Abstrakt

The paper presents the description of method and results of rotor blade shape optimisation. The rotor blading constitutes a part ofturbine flow path. Optimisation consists in selection of the shape that minimises ratio of polytrophic loss. Shape of the blade isdefined by the mean camber line and thickness of the airfoil. Thickness is distributed around the camber line based on the ratio ofdistribution. Global optimisation was done by means of Genetic Algorithms (GA) with the help of Artificial Neural Networks (ANN)for approximations. For the numerical simulation of flow through the model Kaplan turbine, the geometry employed in the model wasbased on actual geometry of the existing test stage. Fluid parameters and boundary conditions for the model were based on experimentalmeasurements which were carried out at the test stand at Department of Turbomachinery and Fluid Mechanics at Gda´nsk University ofTechnology. The shape of blading was optimised for operational point with maximum efficiency.