Developing methods of decomposing the physical resistance components acting on a hydrofoil

Abstract The America’s Cup is a sailing competition contested by teams fielding bespoke yachts designed and built to the AC75 class regulations. These make use of hydrofoils, which permit them lift their hulls above water surface. When in this “foiling” regime, drag forces on hull are drastically lower, permitting greater speed. Predicting hydrodynamic produced from hydrofoils race remains challenging, due wide operating regime complex hydrodynamical phenomena. In study, existing wake survey methods decomposing total force hydrofoil into physical subcomponents were developed through examining sensitivities accuracy. Computational fluid dynamics (CFD) simulations rectangular NACA4412 performed generate data for surveys. was simulated at submergence depth one chord. Viscous flow with k–ω SST turbulence model steady state; volume-of-fluid (VOF) used capture free surface effects. Chord Froude numbers 0.5, 1, 2 4 investigated, corresponding Reynolds 2.57 × 10 5 , 5.15 1.03 6 2.06 . Force decomposition using two different – each wave viscous as well Trefftz plane analysis induced drag. Wave could be reliably isolated all tested numbers, while reliable predictions dependent number method isolating hydrofoil’s region. Accurately component proved challenging interactions. Careful selection location also necessary accurate any components.