Abstract
Some experimental visualizations have been made on the flows past fin keels with or without winglet. Flow patterns on the keels are visualized using a lead white-ammonium sulfide method. A tuft grid is also used to investigate the stream direction in the wake of the fin keel. This results are compared with the velocity vectors measured using a X-probe hot-film velocimeter. Hydrodynamic forces acting on the fin keel are also measured using a load cell.
The experimental results show the winglet expands the area of trailing vortex region in the wake. The winglet also increases lift-curve slope and decreases induced drag of the fin keel.
