The Fourth Lloyd's Register Foundation Lecture on "SPH for Wave Structure Interaction Offshore" by Professor Peter Stansby
Tuesday, 1 November 2016 from 19:00 to 20:00 (SGT)
San Francisco, California
London, United Kingdom
This lecture is about steep and extreme wave structure interaction with structures offshore using the Smoothed Particle Hydrodynamics or SPH methodology. This has developed considerably over the past decade and is well suited to violent surface motions and multi-phase applications.
The lecture will however start with some linear diffraction modelling of complex multi-body wave interaction of a wave energy machine M4 which shows some revealing comparisons with careful experiments in regular, irregular and multi-directional waves. This is particularly relevant in assessing uncertainties in experimental results from wave basins which will apply also to steep waves.
The SPH methodology will be outlined and applications of the standard weakly compressible form will be presented. This is now based on the Dual SPHysics code which runs on GPUs. This is close to providing a numerical wave basin. Simulations with a billion particles are now undertaken. Limitations will be discussed.
The more accurate incompressible SPH will be presented and test results shown. Loading and response in extreme and breaking waves will be shown assuming Froude Krylov forcing with added mass approximations. Developments to include air in two-phase simulations will be presented showing the importance of air on slam loads. A broad range of diverse applications will be shown to demonstrate the versatility of the method.
Finally new developments will be presented. This is mainly to address computational speed and accuracy. The highly accurate Eulerian SPH will be presented, showing how it can be coupled with Lagrangian regions for free surfaces.
About the Speaker
Peter graduated with a degree in Engineering from the Cambridge University in 1971, and a PhD in aerodynamics three years later. His working life began in industry with the Atkins Group as a wind and offshore engineer. In 1980 he moved to the Victoria University of Manchester where he was awarded a DSc for work on vortex methods. He was given an early first Chair there and has since held posts at UMIST, where he was Professor of Hydrodynamics and Head of the Manchester Centre for Civil and Construction Engineering, and at the University of Manchester where he is Professor of Hydrodynamics and was Head of the School of Mechanical Aerospace and Civil Engineering until 2012. He was elected Fellow of the Institution of Civil Engineers in 1991 and of Royal Academy of Engineering in 2001. He became the inaugural Osborne Reynolds Chair in Fluid Mechanics in 2014. He was a member of Research Assessment Exercise Civil Engineering Sub Panel in 2001 and 2008 and of the Severn Barrage Expert Panel for DECC (Phase 1 and 2) in 2008/9.
He has more than 35 years’ experience in fluid mechanics/hydrodynamics research with more than 130 journal papers and has been an investigator on over 50 grants and contracts, mainly from EPSRC. His early research interests were in wave and current loading on offshore structures, including vortex-induced vibrations which resulted in commercial exploitation by Det Norske Veritas (program VISFLO). Since around 1990 he has worked on coastal hydrodynamics, mainly in relation to shallow-water flows and surf zone waves. He led the Coastal Inundation Super Work Package in the EPSRC Flood Risk Management Research Consortium. Since 2004 he has become involved with marine energy research: wave energy device development and tidal stream turbine research, supported by EPSRC and the Energy Technologies Institute. Since 2005 he has become active in the novel numerical method SPH (smoothed particle hydrodynamics) which shows great promise for violent surface flows and flooding.