Cloud Cavitating Flow That Surrounds a Vertical Hydrofoil Near the Free Surface

The Split–Hopkinson pressure bar technology. Three parts the incident bar, the transfer bar, and the test model are included. The launch process is shown.

Speed of the tested hydrofoil changes with time in the water tank experiment from t = 0.001 s to t = 0.014 s

Typical cavitation at t = 0.006 s. The white foam like re-entry jet inside cavity is marked by the line.

Cavity length changes with time from t = 0 s to t = 0.014 s. Three stages of the cavity evolution are marked.

Typical cavitation in cavity growth stage 1 (0.002, 0.006 s). The re-entry jet inside the cavity which is deflected from and is located parallel to the free surface is pointed out by the arrow.

Typical cavitation in cavity shedding stage 2 (0.008 s, 0.009 s, 0.01 s, and 0.011 s)

Typical cavitation in cavity collapsing stage 3 (0.013 s and 0.014 s). The horseshoe cavity structure induced by the re-entry jet is pointed out by the arrows.

Calculated domain and boundary conditions. Boundary conditions that contain inlet, outlet, and wall are marked.

Comparison of the cavity length among the experimental, original mesh, and refined mesh simulated results

Comparison of the cavity evolution between the original mesh and refined mesh simulated results. The detailed structure of the cavity is shown and pointed out by the arrows.

Comparison of the cavity length between the experiment results and the simulation results of cases with constant speeds of 16 m/s, 18 m/s, and 20 m/s

Resulted cavity evolution process of the simulated cases and water tank experiment. The characteristics of the cavitating flow are pointed out by the arrows.

Comparison of the re-entry jet length among the simulation results of 16 m/s, 18 m/s, and 20 m/s

Comparison of the structure of the broken bubble ring at the end of the cavity at t = 0.004 s in the water tank experiment and at t = 0.006 s for the simulation results with and without free surface when the model speed is 16 m/s. Pressure distribution is shown on the surface of the hydrofoil.

Comparison of the experiment image at t = 0.006 s and the velocity contour chart of the cases with and without free surface for the model speed at 16 m/s at t = 0.008 s. The direction of the re-entry jet inside the cavity is pointed out by the arrows.

Comparison of the horseshoe cavity structure at t = 0.008 s in the water tank experiment and at t = 0.01 s for the simulation results with and without free surface when the model speed is 16 m/s. Pressure distribution on the surface of the hydrofoil is shown. The horseshoe cavity structure induced by the re-entry jet is pointed out by the arrows.

Velocity distribution on the added isosurface of Q = 50,000 s⁻² at t = 0.008 s, t = 0.01 s, t = 0.012 s, and t = 0.014 s for the simulated cases at constant speed 16 m/s, 18 m/s, and 20 m/s

Velocity distribution on the added isosurface of Q = 50,000 s⁻² at t = 0.008 s, t = 0.01 s, t = 0.012 s, and t = 0.014 s of the simulated cases with and without free surface when the model speed is 16 m/s

Velocity distribution on the added isosurface of vortex-stretching magnitude is 50,000 at t = 0.008 s, t = 0.01 s, t = 0.012 s, and t = 0.014 s of the simulated cases with and without free surface when the model speed is 16 m/s

Velocity distribution on the added isosurface of vortex-dilatation magnitude is 50,000 at t = 0.008 s, t = 0.01 s, t = 0.012 s, and t = 0.014 s of the simulated cases with and without free surface when the model speed is 16 m/s

Velocity distribution on the added isosurface of baroclinic torque magnitude is 50,000 at t = 0.008 s, t = 0.01 s, t = 0.012 s, and t = 0.014 s of the simulated cases with and without free surface when the model speed is 16 m/s