Physics-Based Design by Optimization of Unconventional Supercavitating Hydrofoils

A computational framework to design a new family of unconventional supercavitating (SC) hydrofoils with optimized hydrodynamic performance is developed. A low\u2010order boundary element method is used to solve for the steady potential flow over the hydrofoil predicting its hydrodynamic characteristics, including the vapor\u2013cavity interface. Shape variations are obtained by an ad hoc parametrization scheme by composite B\u2010spline curves whose control points represent the design variables to the hydrodynamic optimization problem. The accuracy of the Computational Fluid Dynamics (CFD) tools is also preventively validated on the experimental characteristics of a conventional SC hydrofoil. A computational test case is performed to maximize the efficiency of a SC hydrofoil accounting for both shape and angle of attack variations. The new hydrofoil leads to 40% improvement on the lift over drag ratio compared to the initial reference shape. This result is confirmed by high\u2010fidelity unsteady multiphase viscous solver