Hydrodynamic Performance Design of A Monohull Fast Ship with Transom Stern
|Author||Kyaw Naing Aye|
|School||Wuhan University of Technology|
|Course||Design and manufacture of ships and marine structures|
|Keywords||monohull transom stern Michell integral propulsive efficiency strip theory hydrodynamic coefficient wave spectrum response amplitude operator (RAO) maneuverability index|
For a monohull fast ship, predication of hydrodynamic performances plays a significant role in its preliminary design phase. According to ship design spiral, firstly it needs to develop the ship proportion and hull form. And then, it essentially needs to predict the basic hydrodynamic performances such as resistance and powering, seakeeping characteristic and maneuvering performance.Some empirical formulas, which are derived from problem of minimum total resistance, can be adopted for selection of ship proportion or main dimension. Desired hull form can be accomplished by the technique of line distortion from parent ship.Reliable methods, which predict the resistance form the preliminary tools for hydrodynamic performance design. Present time, total resistance is mainly predicted by either experimental method or regression analysis. In this case, former method costs too much, and latter often gets unreliable result. Thus, total resistance is predicted by means of computing wavemaking resistance, frictional resistance and form resistance respectively. Present paper emphasizes the computing of wavemaking resistance and thin ship theory is adopted. Comparison of residual resistance between theoretical approach and experimental results for a fast ship is also presented.To achieve the design information of seakeeping performance, firstly it needs to know the motion response in regular wave by experimental or theoretical approach, and then one can predict theseakeeping performance in its actual seaway by means of linear superposition principle. To predict the motion response in regular wave, two-dimensional method of strip theory is commonly used. Present paper discussed the accuracy of strip theory for prediction of fast ship longitudinal motion response.A new design ship should have good controllability, which permits it to keeping course, to turning and to changing direction in a satisfactory manner. These abilities can be assessed by controllability index. So present paper introduces some hydrodynamic coefficients that influence the ship controllability.Particularly in preliminary design stage, hull form development and power prediction are very important. So present work is focused on this scope. Typical designing of fast ship with transom stern and analyzing of resistance characteristic are presented in last chapter. It attempts to predict the powering performance for that new design ship.