عنوان مقاله [English]
Nowadays the use of high speed crafts has considerably become spread. Of these crafts, due to their high transversal stability and deck area, twin hulls are very important. Similarly in our country considering martial needs, a great deal of concentration is focused on designing these crafts. Hydrodynamic considerations in designing this type of crafts are very important. Using numerical methods for analyzing matters of high speed crafts’ hydrodynamics has greatly become spread in recent years. So much software is produced based on these methods. The good standing CFX is one of those. In this research after modeling a catamaran with 11 meters length, 2 meters width for each hull, and 1.25 meters draft using the mentioned above software, its motion in still water is simulated. By doing so details of the craft’s motion including drag, lift, and pitch are calculated. The ultimate trim of the craft is one another important parameter that is calculated using the model. Besides stability and convergence of the model after almost 6 seconds, in the speed of 20 meters per second, the ultimate trim of the craft is about 4 degrees that greatly resembles to experimental results.