NUMERICAL PREDICTION OF THE CAVITATION AROUND AN UNDERWATER BODY CONSIDERING SURGE MOTION

This paper presents the numerical prediction of the forward speed and moving distance of an underwater body including the analysis of the unsteady characteristics of cavitation developing around the body according to speed change. The flow was assumed to be two-phase incompressible turbulent flow and solved by using the unsteady Reynolds averaged Navier-Stokes method that includes a cavitation model explaining the phase change between the water and vapour. The temporal change of the speed and moving distance of the underwater body estimated from the 1DoF motion analysis showed a satisfactory agreement with the measured results in the underwater test. In addition, the time variations of the cavity predicted along with the speed change of the body also showed a reasonable agreement with the cavity observation of the underwater test. Through this study, we were able to properly explain the drag and speed changes of the underwater body linked to the development of the cavity.