Numerical investigation of maneuvering performance of monohull and multihull marine vessels

Abstract

This Ph.D. study is based on the numerical analysis of the manoeuvring performance of two monohull and two multihull ship forms. To achieve this, the CFD-based system simulation method based on Abkowitz's model has been employed and new closed-form solution techniques have been proposed. The first monohull form is a displacement type surface combatant, which is widely used in the literature and has a significant number of comparison data. It is known by the name DTMB5415, which is the model number in the David Taylor Model Basin (DTMB) experimental laboratory where it was produced. Of the two known configurations of this surface combatant, the one with discontinuous bilge keel geometry and named DTMB5415M has been preferred with full appendages. The second monohull is the R/V Athena, which has the form of a planing hull and is also known in the literature as Model5365. For multihull ships, Delft Catamaran 372 (DC372) and surface combat trimaran have been selected. The CFD-based system simulation method first dictates the development of a mathematical model for ship manoeuvres. Depending on the application purpose, the mathematical model can include environmental factors, rudder forces, propeller forces, hull hydrodynamics and other external effects, if there is any. Hull hydrodynamic characteristics are commonly modelled by special parameters representing the ship hull form. These parameters are the core of the manoeuvring mathematical model and they determine how the ship form will react to any effect entering or leaving the system. These parameters are called hydrodynamic derivatives or manoeuvring coefficients in the literature and can be calculated either experimentally or numerically. Abkowitz's manoeuvring mathematical model has been adopted and the hydrodynamic derivatives have been calculated separately for all selected ship forms by analyzing the planar motion mechanism (PMM) tests with the help of CFD in the computer environment.