The flow in the U9 Kaplan turbine - preliminary and planned simulations using CFX and OpenFOAM
Paper i proceeding, 2008

The present work compares the CFX and OpenFOAM CFD codes with respect to the prediction of the flow in the U9 Kaplan turbine spiral casing, distributor and draft tube. The simulations use similar settings and the same computational grids – unstructured wall-function grids with 10.3M cells in the spiral casing and distributor, and 1.04M cells in the draft tube. The results show that the two codes give similar results in the spiral casing and distributor, and almost identical results in the draft tube. Previous studies [1] have shown the same behaviour in the Turbine-99 draft tube, for a block-structured wall-function grid. There are however no previous studies where the flow in a spiral casing and distributor have been studied and compared using the same settings and computational grid in CFX and OpenFOAM. The next phase of the project consists of comparisons with the results from an on-going experimental investigation.

Draft Tube



Spiral Casing


Water Turbine



Olivier Petit

Chalmers, Tillämpad mekanik, Strömningslära

Håkan Nilsson

Chalmers, Tillämpad mekanik, Strömningslära

Thi VU



24th IAHR Symposium Hydraulic MAchinery and Systems, Foz Do Iguassu, Brasil


Strömningsmekanik och akustik