In this study, electric propulsion leisure boat with 9 meters length is designed and the performances are investigated by CFD analysis and model test. Maximum speed of the developed boat is 15knots(7.7 m/s) using 80Kw electric motor. Catamanan type hull form with slender body is adopted considering high Froude number and large deck area. Two kinds of hull forms are designed and the performances are compared in resistance point of view. Wave patterns are observed to make clear the relationship between resistance performance and wave characteristics. The results show that not only wave interaction due to shoulder waves but also stern waves have a strong influence on resistance performance and CFD analysis including free surface can give useful informations at initial ship design stage for high Froude number catamaran boat.

The small catamaran leisure boat which is 4.1m length, 1.9m breadth and 0.7 ton displacement was designed. To decide optimum breadth, four sets of distances between hulls were considered. CFD analysis using FLUENT was performed to examine flow patterns, pressure distribution and wave height between two hulls. Model test at CWC in INHA Technical College was also carried out to get the resistance for final hull form at design speed 5 knots. The feature of flow pattern among four different distances between hulls were compared and discussed. The optimum breadth of design vessel was decided depending on the CFD results and comments of expertise that has experience on board the small demihull. The design procedure to choose optimum breadth, especially small change of the hull distance, using CFD was described in this paper