Numerical Simulations of Tip Leakage Vortex Cavitation Flows Around a NACA0009 Hydrofoil

Numerical simulations of full wet and cavitating tip leakage vortex flows are studied. By comparing vortex structures, strain rates and Reynolds shear stresses distributions in the vortex region for full wet flows between numerical and experimental results, it is found that the numerical results with the nonlinear k-&epsiv; turbulence model is in good agreement with the experimental results. Both full wet and cavitating flows around a NACA0009 blade with various gaps between the tip and end-wall are studied to investigate the influence of gap width on the development of tip vortex and tip vortex cavitation. Good agreements are obtained on the trajectories of tip leakage vortex by comparing the numerical results and experimental data. When the dimensionless gap size τ < 0.7, numerical results show that there is an apparent difference on the vertex trajectories behind the hydrofoil between full wet and cavitating flows.