Imperial College London

Emeritus ProfessorChrisSwan

Faculty of EngineeringDepartment of Civil and Environmental Engineering

Emeritus Professor of Hydrodynamics
 
 
 
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Contact

 

+44 (0)20 7594 5999c.swan

 
 
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Assistant

 

Miss Rebecca Naessens +44 (0)20 7594 5990

 
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Location

 

329Skempton BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

102 results found

Spinneken J, Swan C, 2009, Wave generation and absorption using force-controlled wave machines, International Offshore and Polar Engineering Conf., Pages: 397-405

Conference paper

Spentza E, Swan C, 2009, WAVE-VESSEL INTERACTIONS IN BEAM SEAS, 28th International Conference on Ocean, Offshore and Arctic Engineering (OMAE), Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 393-403

Conference paper

Spinneken J, Swan C, 2009, Second-order wave maker theory using force-feedback control. Part II. an experimental verification of regular wave generation, Ocean Engineering, Vol: 36, Pages: 549-555

This paper provides an experimental verification of the new wave maker theory outlined by Spinneken and Swan [2009. Second-order wave maker theory using forcefeedback control. Part I. A new theory for regular wave generation. Ocean Engineering, in press, doi:10.1016/j.oceaneng.2009.01.019]. This theory concerns the generation of regular waves by a flap-type wave maker using force-feedback control, providing the first quantitative evidence of the inherent advantages of this latter approach. When the wave maker is controlled by a first-order force command signal, comparisons between the theory and experimental observations confirm two key points: (i) The first-order behaviour is crucial for the absorption characteristics of the machine. (ii) The second-order behaviour leads to a spurious, or unwanted, freely propagating second harmonic that is substantially smaller in amplitude when compared to an identical wave paddle operating with first-order position control. Both aspects of this work, effective absorption and reduced second-order spurious wave generation, are investigated over a broad range of wave frequencies and shown to be widely applicable. Furthermore, the theory also provides a force command signal correct to second order. This is introduced in a separate set of experiments and shown to provide further improvement in the quality of the wave generation.

Journal article

Spinneken J, Swan C, 2009, Second-order wave maker theory using force-feedback control. Part I. A new theory for regular wave generation, Ocean Engineering, Vol: 36, Pages: 539-548

Second-order wave maker theory has long been established; the most extensive and detailed approach given by Schäffer [1996. Second-order wave maker theory for irregular waves. Ocean Engineering 23, 47–88]. However, all existing theories assume the wave paddle is driven by a position-feedback motion controller. Early research in the wave power field led to the design of a force-controlled absorbing wave machine [Salter, S., 1982. Absorbing wave-makers and wide tanks. In: Directional Wave Spectra Applications, pp. 185–200]. In addition to operating as an excellent absorber, this machine seemed to introduce very little spurious harmonic content when driven with a first-order command signal. The present paper provides a mathematical model for the operation of wave makers using force-feedback control and seeks to explain this apparent advantage. The model is developed to second-order so that a command signal compensating for the remaining spurious wave is also provided. Due to the complexity of the problem, the model has been limited to flap-type wave machines and the generation of regular waves. A variety of numerical tests in force-control mode have been conducted, indicating that the spurious wave content is greatly reduced when compared to the position-control mode. A separate experimental study validating the theory is presented in a part II paper by the same authors.

Journal article

Christou M, Swan C, Gudmestad OT, 2008, The interaction of surface water waves with submerged breakwaters, Coastal Engineering, Vol: 55, Pages: 945-958, ISSN: 0378-3839

Journal article

Masterton SR, Swan C, 2008, On the accurate and efficient calibration of a 3D wave basin, OCEAN ENGINEERING, Vol: 35, Pages: 763-773, ISSN: 0029-8018

Journal article

Christou M, Swan C, Gudmestad OT, Roos JSet al., 2008, The interaction of nonlinear waves with the submerged caissons of a gravity-based structure, PROCEEDINGS OF THE 27TH CONFERENCE OF OFFSHORE MECHANICS & ARCTIC ENGINEERING

Conference paper

Gibson RS, Swan C, 2007, The evolution of large ocean waves: the role of local and rapid spectral changes, P R SOC A, Vol: 463, Pages: 21-48, ISSN: 1364-5021

This paper concerns the formation of large-focused or near-focused waves in both unidirectional and directional sea-states. When the crests of wave components of varying frequency superimpose at one point in space and time, a large, transient, focused wave can occur. These events are believed to be representative of the largest waves arising in a random sea and, as such, are of importance to the design of marine structures. The details of how such waves form also offer an explanation for the formation of the so-called freak or rogue waves in deep water. The physical mechanisms that govern the evolution of focused waves have been investigated by applying both the fully nonlinear wave model of Bateman et al. (Bateman et al. 2001 J. Comput. Phys. 174, 277 305) and the Zakharov's evolution equation (Zakharov 1968 J. Appl. Mech. Tech. Phys. 9, 190 194). Aspects of these two wave models are complementary, and their combined use allows the full nonlinearity to be considered and, at the same time, provides insights into the dominant physical processes.In unidirectional seas, it has been shown that the local evolution of thewave spectrumleads to larger maximum crest elevations. In contrast, in directional seas, the maximum crest elevation iswellpredictedby a second-order theory based on the underlying spectrum, but the shape of the largest wave is not. The differences between the evolution of large waves in unidirectional and directional sea-states have been investigated by analysing the results of Bateman et al. (2001) using a number of spectral analysis techniques. It has been shown that during the formation of a focused wave event, there are significant and rapid changes to the underlying wave spectrum. These changes alter both the amplitude of the wave components and their dispersive properties. Importantly, in unidirectional sea-states, the bandwidth of the spectrum typically increases; whereas, in directional sea-states it decreases.The changes to thewave spectra have

Journal article

Gibson RS, Swan C, Tromans PS, 2007, Fully nonlinear statistics of wave crest elevation calculated using a spectral response surface method: Applications to unidirectional sea states, JOURNAL OF PHYSICAL OCEANOGRAPHY, Vol: 37, Pages: 3-15, ISSN: 0022-3670

Journal article

Christou M, Swan C, Gudmestad OT, 2007, The description of breaking waves and the underlying water particle kinematics, 26th International Conference on Offshore Mechanics and Arctic Engineering, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 291-299

Conference paper

Zang J, Gibson R, Taylor PH, Taylor RE, Swan Cet al., 2006, Second order wave diffraction around a fixed ship-shaped body in unidirectional steep waves, 23rd International Conference on Offshore Mechanics and Arctic Engineering (ASME), Publisher: ASME-AMER SOC MECHANICAL ENG, Pages: 89-99, ISSN: 0892-7219

Conference paper

Masterton S, Swan C, 2006, Wave forces on a single surface-piercing column: Comparisons between theory and experiment, 25th International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2006), Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 383-391

Conference paper

Hague CH, Swan C, 2006, Limiting waves in broad-banded, directionally spread seas, 16th International Offshore and Polar Engineering Conference (ISOPE 2006), Publisher: INTERNATIONAL SOCIETY OFFSHORE& POLAR ENGINEERS, Pages: 59-65, ISSN: 1098-6189

Conference paper

Hague CH, Swan C, 2006, Numerical simulations of large deep water waves: The application of a boundary element method, 25th International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2006), Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 167-173

Conference paper

Sheikh R, Swan C, 2005, The interaction between steep waves and a vertical, surface-piercing column, JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING-TRANSACTIONS OF THE ASME, Vol: 127, Pages: 31-38, ISSN: 0892-7219

Journal article

Katsardi V, Swan C, 2005, The evolution of large waves in shallow water, Singapore, 29th international conference on coastal engineering, 2004, Lisbon, PORTUGAL, Publisher: World Scientific Publ Co Pte Ltd, Pages: 69-81

Conference paper

Chan CT, Swan C, 2005, Modelling surface water waves - An application of high-level GLN theory, Singapore, 29th international conference on coastal engineering, 2004, Lisbon, PORTUGAL, Publisher: World Scientific Publ Co Pte Ltd, Pages: 182-194

Conference paper

Katsardi V, Swan C, 2005, The effect of reduced water depth on the description of extreme waves and the prediction of the water particle kinematics, 24th International Conference on Offshore Mechanics and Arctic Engineering, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 547-555

Conference paper

Swan C, Masterton S, Sheikh R, Cavalletti Aet al., 2005, Wave forcing and wave scattering from a vertical surface-piercing cylinder, 24th International Conference on Offshore Mechanics and Arctic Engineering, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 571-580

Conference paper

Johannessen TB, Swan C, 2003, On the nonlinear dynamics of wave groups produced by the focusing of surface-water waves, PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 459, Pages: 1021-1052, ISSN: 1364-5021

Journal article

Bateman WJD, Swan C, Taylor PH, 2003, On the calculation of the water particle kinematics arising in a directionally spread wavefield, JOURNAL OF COMPUTATIONAL PHYSICS, Vol: 186, Pages: 70-92, ISSN: 0021-9991

Journal article

Chan CT, Swan C, 2003, Modelling surface water waves using a high level GLN theory, Proceedings of the 1st international conference on estuaries and coasts, Hang Hou, China, November 2003, Pages: 735-741

Conference paper

Gibson R, Swan C, 2003, Local energy spectra in the vicinity of an extreme wave event (OMAE2003-37249), Offshore mechanics and Arctic engineering; OMAE 2003. Vol 3; materials technology - ocean engineering - Polar and Arctic sciences and technology, Publisher: American Society of Mechanical Engineers, Pages: 589-598

Conference paper

Sheikh R, Swan C, 2003, The interaction between steep waves and a vertical, surface-piercing column (OMAE2003-37154), Offshore mechanics and Arctic engineering; OMAE 2003. Vol 3; materials technology - ocean engineering - Polar and Arctic sciences and technology, Publisher: American Society of Mechanical Engineers, Pages: 557-566

Conference paper

Swan C, Bashir T, Gudmestad OT, 2002, Nonlinear inertial loading. part I: Accelerations in steep 2-D water waves, JOURNAL OF FLUIDS AND STRUCTURES, Vol: 16, Pages: 391-416, ISSN: 0889-9746

Journal article

Smith SF, Swan C, 2002, Extreme two-dimensional water waves: an assessment of potential design solutions, OCEAN ENGINEERING, Vol: 29, Pages: 387-416, ISSN: 0029-8018

Journal article

Gibson R, Tromans P, Swan C, 2002, The exceedence probability of wave crests calculated by the spatial response surface method, Proceedings of the 7th international workshop on wave hindcasting and forecasting, Banff, Canada, October 2002, Pages: 249-260

Conference paper

Bateman WJD, Swan C, Taylor PH, 2001, On the efficient numerical simulation of directionally spread surface water waves, JOURNAL OF COMPUTATIONAL PHYSICS, Vol: 174, Pages: 277-305, ISSN: 0021-9991

Journal article

Johannessen TB, Swan C, 2001, A laboratory study of the focusing of transient and directionally spread surface water waves, PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 457, Pages: 971-1006, ISSN: 1364-5021

Journal article

Swan C, Cummins IP, James RL, 2001, An experimental study of two-dimensional surface water waves propagating on depth-varying currents. Part 1. Regular waves, JOURNAL OF FLUID MECHANICS, Vol: 428, Pages: 273-304, ISSN: 0022-1120

Journal article

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