The designs are based on typical naval frigates and were produced using gradient descent optimization methods and a statistically based hullform resistance code. 2 Frigate at Speed Naval frigates are required to operate at high speeds while remaining efficient at all times.
Designers are therefore very concerned with the hullform resistance of competing designs.
Simplified Hull-form Model A simplified representation of each candidate hullform must be produced for analysis using the resistance model. The analysis is based on a statistical interpretation of a large data-base of results from previous tests on model ships. Variation of Resistance with Speed Hullform resistance rises rapidly with speed and it is clear that at high speeds efficient shapes must be chosen to limit the engine power needed in a design. The hullform of a ship is a highly complex shape but its principal dimensions may be varied by distorting the basic form. Changes in these quantities have a profound affect on the resistance of a ship at a given speed.