Research On Synthetic Evaluation Method For Seakeeping Of A Surface Warship

For surface warship going in seas, seakeeping is one of the most important indexes of determining combat capability and applicability. Seakeeping of a naval ship, composed of many characteristical factors:oscillating motion, acceleration, slamming, deck wetness, increase of resistance and so on, is a complicated hydrodynamics problem, and lies on battle tasks, ocean circumstances, motion response and operation criteria. So, in different stage of ship design, it is necessary that one determining seakeeping index, which can synthetically indicate the seakeeping performance of a naval ship for all battle tasks, is used for evaluating whether the naval vessel designed has a good seakeeping performance and combat applicability required.This thesis is divided in to four areas. Initially a Deep Vee and Round Bilge frigates are considered for comparison. These frigates of equal displacement (1500tonnes) and the different advantages and disadvantages of the frigates are reviewed from behavior of initial stability, seakeeping performance and resistance. The frigate hulls are modeled and studied using Maxsurfsoftwars. Secondly In order to determine the effects of midship deadrise angle on stability, seakeeping and resistance, a family of five Deep Vee frigate hulls having the same displacement and length was designed using Maxsurf software, midship deadrise angles chosen are2°,23°,25°,27°,29°. Deadrise angle was taken constant from midship to the stern and it means that the midship deadrise and transom deadrise are equals. In The third section another family having the same midship deadrise angle βM=25°and different transom deadrise angles βT5°,10°,15°,20°,25°are considered to investigate the influence of transom deadrise. In the fourth section tow Deep Vee hulls having the same displacement and length were designed by modify existing parent hull, the first hull has an immersed bow while the second has a bulbs bow.