On the relation between friction losses and pressure pulsations caused by Rotor Stator interaction on the Francis-99 turbine

Francis-99 Workshop 2: transient operation of Francis turbines

Østby, Petter T.K.^1,2 ; Billdal, Jan Tore^2 ; Haugen, Bjørn^1 ; Dahlhaug, Ole Gunnar^1

Norwegian University of Science and Technology, Trondheim, Norway^1

Rainpower Norge AS, Norway^2

关键词: Development time;    Friction loss;    Inviscid flows;    Pressure amplitudes;    Pressure pulsation;    Rotor-stator interactions;    Safe operation;    Wall friction;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/782/1/012010/pdf
DOI  :  10.1088/1742-6596/782/1/012010

来源: IOP

【 摘 要 】

High head Francis runners are subject to pressure pulsations caused by rotor stator interaction. To ensure safe operation of such turbines, it is important to be able to predict these pulsations. For turbine manufacturers it is often a dilemma whether to perform very advanced and time consuming CFD calculations or to rely on simpler calculations to save development time. This paper tries to evaluate simplifications of the CFD model while still capturing the RSI phenomena and ensuring that the calculation does not underpredict the pressure amplitudes. The effects which turbulence modeling, wall friction, viscosity and mesh have on the pressure amplitudes will be investigated along with time savings with each simplification. The hypothesis is that rotor stator interaction is manly driven by inviscid flow and can therefore be modeled by the Euler equations.