Parameter based tool for Francis turbine guide vanes design using coupled MATLAB - ANSYS approach

Abstract

The complex geometry of Francis turbine components can be defined parametrically so that automatic optimization techniques based on parametrization can be used. This is convenient for a hydraulic redesign of individual turbine elements. Considering the importance of the guide vane cascade in defining the flow entering the runner, a parametric design tool is established to design the stationary parts of a Francis turbine with variable-speed capabilities and optimize the guide vanes. For a given runner geometry and turbine operating conditions, variety of different guide vane designs may be produced. The calculation procedure for obtaining the curves which are basis for generating the stationary turbine components is performed in the software MATLAB. The script is then connected with the Computational Fluid Dynamics and Finite Element Method analysis software ANSYS Workbench to automate the process of geometry generation, meshing, modelling and simulation of three-dimensional stationary water flow in the turbine and structural analysis of the guide vanes. The tool proves to be very useful for collecting results related to the guide vane hydraulic and mechanical performance, towards obtaining an optimal guide vane design. A model of a Francis turbine is used as a test case.

Keywords

• guide vanes; variable-speed operation; parametrization; cfd; fem; francis turbine.