Ventilated supercavitation involves enveloping a submerged high-speed body within an artificially generated air supercavity to drastically reduce hydrodynamic resistance. Investigating such flows near the free surface is essential due to the interaction between supercavity dynamics and free surface condition at different flow specifications. This work numerically studies the effect of the submergence depth, Froude number, and ventilation rate on the flow characteristics of a disk-cavitator body in ventilated cavitating flow. The simulation is executed using the finite volume-based commercial package ANSYS CFX 15, and accuracy of the simulation predictions are validated by comparison with corresponding experimental data. The results indicate that, unlike typical surface bodies where drag decreases with depth, the drag coefficient of the model with a disk-shaped cavitator under ventilated supercavitation increases with depth. Supercavity shape analyses further show that proximity to the free surface leads to shorter and wider cavities, while deeper submergence results in longer and more slender cavity forms. Moreover, the drag coefficient decreases with increasing Froude number, reflecting reduced wave-making effects. Higher ventilation rates also produce larger supercavities in both length and diameter, with more pronounced effects at lower depths.

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