engleski

Validation of Francis Turbine CFD Simulations

This paper compares data from calculated and measured results covering the whole operating range for a 20 MW Francis turbine in order to validate the CFD simulation. Computed hydraulic characteristics are determined for each analyzed operating point by running numerical simulations of turbulent fluid flow through a complete Francis Turbine model using the commercial fluid flow solver Fluent. The measured hydraulic characteristics were defined by on-site measurements according to the IEC 41 international field acceptance test standard. The computed characteristics show very good conformity of values and trend-lines with measured characteristics over the whole operating range. The deviations are lowest around the optimum and increase towards the boundaries of the operating range where the vorticity in the turbine diffuser is more significant. The aim was to analyze the behavior of the existing turbine and fine-tune the whole numerical experiment to achieve the level of accuracy necessary for a concept design of a revitalized turbine.

CFD; fluent; Francis turbine; hydraulic characteristics; hydraulic turbomachine

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