Numerical simulation and analysis of fluid-structure interaction on 3D MHKF-180 and NACA4418 cavitating hydrofoils

Abstract

A numerical investigation of structural and hydrodynamic performance of 3D stainless steel MHKF-180 and NACA4418 cavitating hydrofoils has been carried out using one-way fluid-structure interaction (FSI). Under the application of hydrodynamic load, the structural performance of MHKF-180 is compared with NACA4418 in terms of natural frequency, maximum tip deformation, and von Mises stress, whereas hydrodynamic performance is compared in terms of lift coefficient, drag coefficient, lift to drag ratio, pressure coefficient, and Strouhal number. The simulation is performed at a chord-based Reynolds number, Re = 750000, for different cavitation numbers and angles of attack using ANSYS software. The present result is validated by comparing the natural frequency and pressure coefficient curve of the non-cavitating NACA66 hydrofoil and lift coefficient and drag coefficient of cavitating NACA4412 hydrofoil with the available experimental data. The fluid flow is simulated using the unsteady-Reynolds-averaged-Navier-Stokes (URANS) equations and Realizable k −ε turbulence model. The cavitation effect on the hydrofoil is studied using the Zwart-Gerber-Belamri cavitation model. Comparing the maximum tip deformation under cavitation, the MHKF-180 shows larger tip deformation than NACA4418 hydrofoil. However, the hydrodynamic performance, assessed in terms of lift coefficient, MHKF-180 gives a better than NACA4418 under the cavitating condition at different angles of attack and for different cavitation numbers.