Identification of the wave speed and the second viscosity in cavitating flow with 2D RANS computations - Part II

9th International Symposium on Cavitation

Alligné, S.^1 ; Decaix, J.^2 ; Nicolet, C.^1 ; Avellan, F.^3 ; Münch, C.^2

Power Vision Engineering Sàrl, Chemin des Champs Courbes 1, Ecublens

1024, Switzerland^1

HES so Valais-Wallis, Route du Rawyl 47, Sion 2

1950, Switzerland^2

EPFL Laboratory for Hydraulic Machines, Avenue de Cour 33 bis, Lausanne

1007, Switzerland^3

关键词: Cavitating flow;    Cavitation model;    Cavitation vortex ropes;    CFD simulations;    Flowthrough;    Outlet boundary condition;    Pressure fluctuation;    Simplified test;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012057/pdf
DOI  :  10.1088/1742-6596/656/1/012057

来源: IOP

【 摘 要 】

The 1D modelling of cavitation vortex rope dynamics in Francis turbine draft tube is decisive for prediction of pressure fluctuations in the system. However, models are defined with parameters which values must be quantified either experimentally or numerically. In this paper a methodology based on CFD simulations is setup to identify these parameters by exciting the flow through outlet boundary condition. A simplified test case is considered to assess if 1D cavitation model parameters can be identified from CFD simulations. It is shown that a low wave speed and a second viscosity due to the cavitating flow can be identified.