CFD Investigations on Drag Reduction due to Cavitator Heads on Supercavitating Bodies

Abstract

Abstract In the present study, a supercavitating elliptical body was investigated, using the commercial CFD Solver Star-CCM+. For the study the Reynolds Averaged Navier-Stokes Equation was solved using the realizable k-ε turbulence model. The cavitation model that was used is the Schnerr-Sauer model. The shape of the elliptical bodies was designed according to the empirical formula of Reichardt for cavitation bubbles, which is almost an ellipse where the ratio of the semi-axes of the quasiellipse is given as a function of the cavitation number. The present studies include investigations without a cavitator at the tip and with a flat, round and conical cavitator head design at the tip. The different designs were simulated for various Reynolds numbers. For all studies, the drag coefficient was evaluated. For better understanding the drag coefficient is split into two parts, the shear drag coefficient and the pressure drag coefficient. The results are shown in dependency of the dimensionless Reynolds number. In the simulations, the Reynolds number was changed by increasing the velocity and changing the characteristic length.