Chapter 3
Introduction to Computational Fluid Dynamics
and Ocean Modelling
Tomas Torsvik
Abstract This chapter provides a short introduction to the most commonly used
numerical methods in computational fluid dynamics, and some specific aspects of
numerical modelling of ocean currents. When working with numerical models, it
is essential to have a basic understanding of the possibilities and limitations of the
modelling toolbox. The first part gives a demonstration on how the model differential equations for fluid motions can be transformed into computer code instructions.
Important concepts such as consistency, stability and convergence are discussed.
The second part of the chapter provides an introduction to ocean modelling, with
emphasis on the approximations that are commonly used in general circulation models.
3.1 Introduction
Computational Fluid Dynamics (CFD) is a branch of fluid mechanics where fluid
flow problems are analysed by numerical methods. As a scientific field of study,
CFD is intimately related to the physics of fluids and the mathematical formulation
of fluid mechanics, as well as the theory of computation and algorithms and the
constant evolution of computer architecture. The complexity of CFD models varies
greatly, depending on the geometry of the flow problem, the physical properties
of the fluid and number of fluid components, and restrictions imposed by the flow
regime (e.g., turbulent vs. laminar flow, subsonic vs. supersonic flow, etc.). Some
models also incorporate chemical or biological effects in the flow problem.
While many CFD codes can run and produce useful results on simple desktop
computers, the development of large and complex computer models, and the fact
that even simple flow problems often display a high degree of complexity, have
pushed the demand for computational power. The CFD community is a prominent
part within High Performance Computing (HPC), and the evolution of CFD codes
T. Torsvik (B)
Wave Engineering Laboratory, Institute of Cybernetics at Tallinn University of Technology,
Akadeemia tee 21, 12618 Tallinn, Estonia
e-mail: tomas.torsvik@ioc.ee
T. Soomere, E. Quak (eds.), Preventive Methods for Coastal Protection,
DOI 10.1007/978-3-319-00440-2_3,
© Springer International Publishing Switzerland 2013
65
Introduction to Computational Fluid Dynamics
and Ocean Modelling
Tomas Torsvik
Abstract This chapter provides a short introduction to the most commonly used
numerical methods in computational fluid dynamics, and some specific aspects of
numerical modelling of ocean currents. When working with numerical models, it
is essential to have a basic understanding of the possibilities and limitations of the
modelling toolbox. The first part gives a demonstration on how the model differential equations for fluid motions can be transformed into computer code instructions.
Important concepts such as consistency, stability and convergence are discussed.
The second part of the chapter provides an introduction to ocean modelling, with
emphasis on the approximations that are commonly used in general circulation models.
3.1 Introduction
Computational Fluid Dynamics (CFD) is a branch of fluid mechanics where fluid
flow problems are analysed by numerical methods. As a scientific field of study,
CFD is intimately related to the physics of fluids and the mathematical formulation
of fluid mechanics, as well as the theory of computation and algorithms and the
constant evolution of computer architecture. The complexity of CFD models varies
greatly, depending on the geometry of the flow problem, the physical properties
of the fluid and number of fluid components, and restrictions imposed by the flow
regime (e.g., turbulent vs. laminar flow, subsonic vs. supersonic flow, etc.). Some
models also incorporate chemical or biological effects in the flow problem.
While many CFD codes can run and produce useful results on simple desktop
computers, the development of large and complex computer models, and the fact
that even simple flow problems often display a high degree of complexity, have
pushed the demand for computational power. The CFD community is a prominent
part within High Performance Computing (HPC), and the evolution of CFD codes
T. Torsvik (B)
Wave Engineering Laboratory, Institute of Cybernetics at Tallinn University of Technology,
Akadeemia tee 21, 12618 Tallinn, Estonia
e-mail: tomas.torsvik@ioc.ee
T. Soomere, E. Quak (eds.), Preventive Methods for Coastal Protection,
DOI 10.1007/978-3-319-00440-2_3,
© Springer International Publishing Switzerland 2013
65