Abstract:

The methöd of Computational Fluid Dynamics (CFD) is adopted to carry out a lump-sum analysis of Francis turbine. Irr the analysis , the turbine is divided into several regions including the spiral casing , the stay vane , the guide vane , the runner and the draft tube. According to the variation of the residual error for each re-gion, the sufficient convergence of the residual error for the runner is used as the criterion for the iterative computa-tion.
Then , with the Francis turbine in a hydropower plant as the object , the dimensionless pressure of the turbine is obtained , which is then employed to predict the time and position of cavitation on the suction surface of the run-ner vane. The predicted results accord well with the practical ones , thus verifying the effectiveness of the proposed method.

Key words: Francis turbine, lump-sum analysis, runner, cavitation prediction