Development and application of high-speed underwater vehicle is the cause for considering super-cavitating flows by many researchers. Frictional drag decreases and vehicle’s velocity increases due to cavity generation. The objective of the present research is to find the coefficients of an optimized equation to estimate cavity length around a submercible vehicle equipped with a wedged-shaped cavitator which has important practical applications. For this purposes, the super cavitation phenomena has been simulated numerically around three bodies with different geometry. At first stage, to validate the results of numerical simulation of present work a well-established experimental result of a cylindrical body with hemispheric cap is used for comparison. This comparison is used for parameters effecting numerical method, turbulence flow model and mass transfer model. As this comparison is confirmed, the simulation is continued at second stage for super cavitation phenomena initiation around a wedged-shaped cavitator with two 15 and 45 degrees angle. At third stage, the super cavitation flow is analyzed around a submersible body equipped with a wedged-shaped cavitator. The cavity length and related coefficients are obtained for three cases using different cavitation numbers. The developed equation is similar for all cases with different coefficients. The averaged Navier-Stokes equations are solved in transient case using finite volume method. Different mass transfer models with turbulent flow models are used at different conditions. The numerical results are validated with experimental results of other researchers. Comparison is encouraging.