Abstract:
Hydrodynamic optimization is an important aspect of ship design. The aim of this dissertation
is to develop a computational fluid dynamics (CFD)-based computational tool for
the hydrodynamic design of ship hull forms. The main components of this hull-form hydrodynamic
optimization tool consist of a hull geometry modeling and modification module, an
optimization module, and a CFD module. This CFD-based multi-objective optimization
tool can automatically modify the shape of a ship hull by minimizing some user-defined
objective functions associated with the hydrodynamic performance of the ship with the aid
of CFD information.
This dissertation covers three main topics. The first topic is the development of a
geometry modeling method to produce the initial hull form and to modify the hull surface
during optimization cycles. Three hull-form modeling methods are developed, which are
NURBS representation, parametric representation, and the combination of the NURBS and
parametric representation to represent a complex geometry and to satisfy different design
requirements. The second topic is the development of various optimization algorithms. Both
single- and multi-objective optimization algorithms are implemented. Several optimization
algorithms are employed and compared with one another in various hull form optimization
applications. Finally, a CFD module is developed to compute the flow field and evaluate
the hydrodynamic performance of the new hull forms obtained during optimization cycles.
A lower-fidelity CFD tool (computer code SSF) and a high-fidelity CFD tool (computer
code FEFLO) are integrated into the CFD module to allow fast evaluation of the objective
functions during design cycles and accurate analysis of the flow about the final optimal hull.
The CFD-based multi-objective optimization tool developed under this dissertation has
been validated and applied in the design of various types of ships. A diverse set of optimal
hull forms can be obtained using the present hydrodynamic optimization tool and significant
improvement in hydrodynamic performance can be achieved.
