Study on ventilated supercavitation in vertical and lateral gust flows

In realistic operational settings, underwater vehicles often encounter unsteady incoming flows; however, the implications of such disturbances on ventilated supercavitation remain insufficiently understood. This study addresses this gap by analyzing the effects of vertical and lateral gust flows on the physical characteristics of a ventilated supercavity—knowledge that is critical for enhancing control mechanisms in supercavitating vehicles. The simulations utilize the volume of fluid method with the realizable k–ε turbulence model, incorporating periodic inlet disturbances via a superimposed cosine function. Following validation against experimental benchmarks, gust flows are modeled at frequencies of 10, 15, and 20 Hz across three Froude numbers: 15.25, 20.33, and 25.41. The results indicate that gust flows significantly modify cavity morphology, inducing pinch-off events and promoting a shift from twin-vortex to re-entrant jet closure modes. At fixed Froude numbers, increasing gust frequency leads to a progressive reduction in total cavity length, with vertical gusts inducing more substantial reductions than lateral gusts. Conversely, the maximum cavity diameter remains largely unaffected by gust frequency. Additionally, both gust directions reduce ventilation air concentration and static pressure within the cavity, resulting in elevated local cavitation numbers. These flow disturbances also introduce pronounced unsteadiness in the hydrodynamic forces: The streamwise and vertical components of the hydrodynamic force are primarily affected by vertical gusts, whereas the lateral component is influenced by later gusts.