CFD feasibility study

to increase the output of an existing hydropower plant in Paraguay

On behalf of a renowned, internationally active planning company, Jaberg & Partner carried out a CFD-based feasibility study to increase the output of a hydropower plant in Paraguay.

Using the as-built drawings from 1968, a 3D model of the Francis turbines was developed, which was used to create meshes. The aim was to develop a new runner design while retaining the geometries of the spiral, guide vane and draft tube, to achieve the greatest possible increase in output. Due to large water reserves, the power plant is to be used to cover peak loads in the future.

It turned out that the increase in performance is primarily limited by the cavitation limit of the runner, which in turn depends on the extremely fluctuating underwater level over time. In the end, a slightly increased turbine speed and a customised new Francis runner made it possible to achieve a theoretical, cavitation-proof performance increase of up to 30%!

The simulation results and findings obtained in the course of the feasibility study serve as the basis for a comprehensive tender for the refurbishment of the existing hydropower plant.