Numerical study on the effect of airfoil attack angle and height on the resistance reduction of the planing trimaran

Abstract

The planing trimaran has unique rapidity and stability. In this paper, airfoils are added to the planing trimaran to provide additional aerodynamic and hydrodynamic lift, achieving the purpose of reducing the resistance of the planing trimaran. By solving Reynold-Averaged Navier-Stokes (RANS) equations and combining SST k-Omega turbulence model with Volume of Fraction (VOF) method, a numerical simulation method is established to analyze the motion characteristics of the planing trimaran. The attack angle and the height of airfoils are mainly studied in this paper. NACA4404 and a special airfoil named 2# airfoil are selected as the research objects. The range of attack angle is 0–8°. The drag reduction effect of the airfoil does not change linearly with the increase of the attack angle in the high speed range. NACA4404 and 2# airfoil have the best drag reduction effect at 2°and 4°respectively. The range of airfoil height is 0.8h–1h (“h” is the wing height from baseline). For NACA4404, lower wing height is beneficial to reduce the resistance, especially in the low speed range. The 2# airfoil has poor performance in the low speed range after reducing the height, and can increase the resistance by up to 16.3%.