Large eddy simulation of turbulent cavitating flows

9th International Symposium on Cavitation

Gnanaskandan, A.^1 ; Mahesh, K.^1

Aerospace Engineering and Mechanics, University of Minnesota, United States^1

关键词: Auto-oscillations;    Cavitation number;    Compressible fluids;    Dynamic Smagorinsky models;    Governing equations;    Homogeneous mixtures;    Predictor-corrector methods;    Void fraction profiles;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012135/pdf
DOI  :  10.1088/1742-6596/656/1/012135

来源: IOP

【 摘 要 】

Large Eddy Simulation is employed to study two turbulent cavitating flows: over a cylinder and a wedge. A homogeneous mixture model is used to treat the mixture of water and water vapor as a compressible fluid. The governing equations are solved using a novel predictor- corrector method. The subgrid terms are modeled using the Dynamic Smagorinsky model. Cavitating flow over a cylinder at Reynolds number (Re) = 3900 and cavitation number (σ) = 1.0 is simulated and the wake characteristics are compared to the single phase results at the same Reynolds number. It is observed that cavitation suppresses turbulence in the near wake and delays three dimensional breakdown of the vortices. Next, cavitating flow over a wedge at Re = 200, 000 and σ = 2.0 is presented. The mean void fraction profiles obtained are compared to experiment and good agreement is obtained. Cavity auto-oscillation is observed, where the sheet cavity breaks up into a cloud cavity periodically. The results suggest LES as an attractive approach for predicting turbulent cavitating flows.