Investigation on Rudder Hydrodynamics for 470 Class Yacht

The rudder is an important appendage and used to adjust the course and balance the lateral displacement in the sailing regatta. RANSE (Reynolds-averaged Navier-Stokes Equations) was used to simulate the viscous flow field of the hull for 470 Class yacht based on CFD (Computational Fluid Dynamics). It is found that the stall angle was 30 degrees when the displacement is 280 kg and the boat speed is 2 m/s to 8 m/s. If the speed increases, the wake flow of the hull will influence the valid area of the rudder and span-chord ratio and the stall angle will be 35 degrees at the speed of 10 m/s. The lift-drag ratio will increase when the rudder angle is from 10 degrees to 25 degrees. The results would provide a theoretical reference for athletes to manipulate the sailboat.