Numerical Simulations of Supercavitating Propellers and Hydrofoils

Abstract

A systematic investigation is conducted to compare and evaluate the hydrodynamic performance and cavitation pattern prediction capabilities of URANS and BEM solvers for supercavitating propellers (SCPs) and hydrofoils (SCHs) with non-conventional sectional profiles. The previously developed BEM at the VT Innovative Ship Design Lab (VT-iShip) is extended upon to allow for supercavitating profiles with truncated trailing edges (TE). Both the BEM and the URANS solutions are validated against experimental data for a range of operating conditions and their discrepancies from experimental trends are quantified. The predicted solutions from both methods closely overlap with experimental data and contain an experimental error in the order of 10% for a large range of operating conditions. Some novel contributions in this study include various theoretical developments that allow the BEM to now consider a large number of supercavitating conditions for supercavitating profiles with truncated TEs. The theoretical modifications to the BEM algorithms are developed into BEM executable frameworks for 2D and 3D SCHs and SCPs. Moreover, the novel contributions also include the identification of select URANS turbulence and cavitation models to most accurately predict supercavitating propeller and hydrofoil performance parameters and cavitation patterns. These solutions are compared with BEM solutions. A design space evaluation of each method is also conducted along with various experimental validation studies to evaluate the robustness of the BEM algorithm. A comparison of their required computational and time-based resources reveals that the methods can be used in a complementary manner for a large range of operating conditions when evaluating designs in the supercavitating regime.