Lift-Drag Coefficient and Form Factor Analyses of Hydrofoil due to The Shape and Angle of Attack

摘要

The objective of this research is to obtain the NACA foil type which is appropriate to be applied in a ship using hydrofoil. There are three parameters that are used as criterion to determine the best foil. Lift-drag coefficient effect on the lift ability and the resistance of foil. Form factor means that the block coefficient of foil which is as the part of drag coefficient. This research is carried out using numerical method. There are three foils based on the NACA series comprise NACA 2212, NACA 2309, and NACA 4712. Meanwhile, the angle of attack is varied in 0, 5, 10, 15, 20, and 25 degrees. For the form factor analysis, the fluid flow is simulated in low speed. For the lift-drag coefficient, the fluid is run in high speed. The characteristics of optimum foil cover: 1) at the specified speed, the foil have the maximum lift force and is able to withstand the drag; 2) the foil have minimum form factor; and 3) the stall phenomenon does not occur in the selected NACA foil. From these characteristics and analyses of the foil, the NACA 4712 with the angle of attack 15 degrees is the best foil to be applied in hydrofoil.