Showing posts with label Waves. Show all posts
Showing posts with label Waves. Show all posts
Tuesday, 6 January 2015
Foundation course in the numerical modelling of waves and tides (Understanding the Coastal Ocean)
We have received a lot of interest in the forthcoming ‘Foundation course in the numerical modelling of waves and tides (Understanding the Coastal Ocean)’ training course. Feedback from interested parties - including those who have already signed up for the course - suggests that the course was originally scheduled too early in the new year. As such, we have taken the difficult decision to reschedule the course for later in the year (we would tentatively propose a date in June 2015).
We will take this additional time to review the course content to ensure that it best serves those registered (particularly those participants from UK and Ireland Consultants) - the course has been designed to teach participants numerical modelling in the marine environment using MIKE 21; reinforcing hands on exercises with robust theory.
In the meantime, if you are interested in attending the course, please e-mail sjf@dhigroup.com. For those participants who have already registered, we will take your interest forward and keep you informed.
Monday, 15 December 2014
Understanding the Coastal Ocean: A foundation course in the modelling of waves and tides
Date: 19th to 21st January 2015
Venue: Queen’s University, Belfast, UK
Cost: GBP 795 excl. VAT (discounted rate of GBP 675 excl. VAT for registered students)
Registration: http://www.theacademybydhi.com/course-sessions/understanding-the-coastal-ocean-26600004-03
THE ACADEMY by DHI and Queen’s University, Belfast have designed a three day hands-on foundation course to give delegates a basic introduction to the science behind wave and tidal models. The course is targeted at either early career professionals or those changing disciplines who wish to understand both the underlying processes and their practical application in engineering consultancy. The course outline is shown below:
Day 1 Morning: Theoretical Background & Engineering Considerations of Tides
- how are tides generated (general ocean circulation, Coriolis, tide-producing forces)?
- why do tides vary around the world (tidal constituents, tidal analysis, shallow water harmonics)?
- how does the ocean interact with its boundaries (bed friction, edge friction, wetting/drying, wind forcing, thermal/saline exchange)?
- how to define model domain (tidal excursion, flowfield considerations, importance of vertical datum)
- where to get data from (measurements, data sources, data types)
- how to improve confidence in your model (calibration and validation)
- an introduction to the model interface (physical parameters, what is eddy viscosity, tunable parameters)
- creating a new fine-scale model (mesh, boundaries)
- tuning your fine-scale model (calibration and validation)
- how are waves created and modified (basic wave theory, interaction with boundaries, processes in deep and shallow water)
- introduction to wave spectra (wave energy distribution, parameterisation of wave climate)
- wave measurement methods (interpreting observations)
- spectral wave modelling (fully represented and parameterised processes, assumptions, model domain)
- an introduction to the model interface (solution schemes, consideration of formulation options)
- convergence information (understanding its use)
- creating a new fine-scale model (boundaries)
- understanding and improving your wave model results (how to spot issues, calibration and validation)
- introduction to the coupled model
We have designed the course to have a wide field of application and therefore anticipate a high level of interest so don’t miss out, book your place today!
The UK Team
Tuesday, 12 August 2014
Teaching and research with MIKE by DHI - Dr Björn Elsäßer (Queen’s University Belfast)
Presented at the 2014 MIKE by DHI UK Symposium on 13th to 14th May 2014.
Teaching and research with MIKE by DHI - Dr Björn Elsäßer (Queen’s University Belfast) from sjf_dhi
Presented at the 2014 MIKE by DHI UK Symposium on 13th to 14th May 2014.
Thursday, 29 November 2012
MIKE 21 Quick Start Guide (Flexible Mesh Series)
Over the past few months, we have prepared several short instructional documents in the use of the MIKE Zero Mesh Generator, MIKE 21 FMHD and MIKE 21 SW from a UK perspective. These instructions have been collated into the informal working document 'MIKE 21 Quick Start Guide' below: -
We have been working hard to enhance our User Manuals and Scientific Documentation. For example, the above informal guide can be augmented by our new Mesh Generator Step-by-step Guide (2012): -
How to Create a Directional Wave Spectrum for Input to MIKE 21 SW from Buoy Data
In order to make best use of the new Wave Spectra Converter tool available in Release 2012, some pre-processing of wave buoy data is generally required. In response to a number of recent enquiries, we have prepared the following informal guidance: -
Oil Spill Modelling
It is important to note that the methodologies of the old and new oil spill models in MIKE 21/3 are very different, and a direct comparison is difficult. However, in order to provide some basic guidance, we have developed the following comparison document and associated example models (provided here for information and discussion only): -
Over the past few months, we have prepared several short instructional documents in the use of the MIKE Zero Mesh Generator, MIKE 21 FMHD and MIKE 21 SW from a UK perspective. These instructions have been collated into the informal working document 'MIKE 21 Quick Start Guide' below: -
We have been working hard to enhance our User Manuals and Scientific Documentation. For example, the above informal guide can be augmented by our new Mesh Generator Step-by-step Guide (2012): -
How to Create a Directional Wave Spectrum for Input to MIKE 21 SW from Buoy Data
In order to make best use of the new Wave Spectra Converter tool available in Release 2012, some pre-processing of wave buoy data is generally required. In response to a number of recent enquiries, we have prepared the following informal guidance: -
Oil Spill Modelling
It is important to note that the methodologies of the old and new oil spill models in MIKE 21/3 are very different, and a direct comparison is difficult. However, in order to provide some basic guidance, we have developed the following comparison document and associated example models (provided here for information and discussion only): -
Wednesday, 14 November 2012
Congratulations to Plymouth University on the official opening of its new Marine Building
Plymouth University's new £19 million state-of-the-art Marine Building was officially opened by HRH Prince Philip The Duke of Edinburgh on 30 October 2012. The facility is currently thought to house the UK's most sophisticated wave energy testing tank which will enable developers to test wave energy devices (using waves, currents and wind) prior to linking up to the Wave Hub – a grid-connected test site about 10 miles off the coast at Hayle in Cornwall.
More details can be found via the links below: -
To celebrate the opening of its new Marine Building the University commissioned Alexis Kirke and Sam Freeman to create and perform a unique musical composition for large-scale wave tank, water drummers and electronics. The piece, Sound-Wave, is thought to be the first time a wave tank has been turned into a musical instrument.
Alexis Kirke, with sensors strapped to his body, conducted the 12-minute symphony of waves and music from a position above the main tank. Water drummers (Josie Boucharde, Philip J. Kendall, Magdalena Walker and Jennie Pinhey) provided percussion in the nearby coastal tank. Visit Alexis Kirke's web page to see how it was done.
Plymouth University's new £19 million state-of-the-art Marine Building was officially opened by HRH Prince Philip The Duke of Edinburgh on 30 October 2012. The facility is currently thought to house the UK's most sophisticated wave energy testing tank which will enable developers to test wave energy devices (using waves, currents and wind) prior to linking up to the Wave Hub – a grid-connected test site about 10 miles off the coast at Hayle in Cornwall.
More details can be found via the links below: -
- http://www1.plymouth.ac.uk/location/campusdevelopments/marinebuilding/Pages/default.aspx
- http://www1.plymouth.ac.uk/location/campusdevelopments/marinebuilding/Pages/Official-opening-image-gallery.aspx
- http://www.plymouth.ac.uk/files/extranet/docs/MARINST/Marine%20Building%20Brochure.pdf
- http://www.bbc.co.uk/news/uk-england-devon-20135074
- http://www.thisiscornwall.co.uk/Duke-Edinburgh-opens-new-marine-building-ndash/story-17200988-detail/story.html
To celebrate the opening of its new Marine Building the University commissioned Alexis Kirke and Sam Freeman to create and perform a unique musical composition for large-scale wave tank, water drummers and electronics. The piece, Sound-Wave, is thought to be the first time a wave tank has been turned into a musical instrument.
Alexis Kirke, with sensors strapped to his body, conducted the 12-minute symphony of waves and music from a position above the main tank. Water drummers (Josie Boucharde, Philip J. Kendall, Magdalena Walker and Jennie Pinhey) provided percussion in the nearby coastal tank. Visit Alexis Kirke's web page to see how it was done.
Tuesday, 27 September 2011
Example MIKE 21 Coupled Model to investigate swell wave propagation in the English Channel
Introduction
In February this year (2011) a large storm in the North Atlantic caused swell waves with periods of 20-25 seconds to propagate into the English Channel. Whilst this is not unusual in itself (beaches along the south coast have historically been subject to similar storms), the combination with high water of these small wave height, long period waves led to a series of flooding “near misses” along the South Coast as swell waves led to damage and overtopping of some defences including natural barrier beaches.
It is important to note that many of the beaches along the south coast are gravel/shingle dominated barriers which are typically considered reflective in morphological classifications (Short 1979). Greenwood (1984) noted that reflective beaches, which are already prone to sub-harmonic edge waves, can interact with longer period swell waves leading to an amplification of wave run up, a mechanism which leads to higher than anticipated overtopping and overwashing of the crest with consequent implications for barrier stability and hinterland flooding. With increasing emphasis from operating authorities being placed on beach management of such natural defences, it is important to understand the driving conditions in an event such as this to plan effective management.
With this in mind, DHI have developed a demonstration model of this event to show how the Flexible Mesh series of models allows you to take large scale North East Atlantic basin driving forces to understand the impact at a local scale. The coupled model developed makes use of the Spectral Wave and Hydrodynamic modules of the MIKE by DHI software and uses freely available data sources as inputs.
For this regionally focused modeling study, bathymetry data has been sourced from the GEBCO 08 Grid bathymetry data set which provides a 30 arc-second grid of the entire globe. Tidal data was obtained from the MIKE 21 toolbox to allow the flow model to be adequately resolved.
In addition the driving forces of the storm in the North East Atlantic needed to be represented. For this the NOAA/NCEP reanalysis data was used. This data set can provide driving wind fields and pressures for the entire globe and a temporal and spatial subset was utilized for this demonstration. The NOAA/NCEP reanalysis data is 6 hourly at a spatial resolution of 2.5 degrees. Available pressure charts from the UK Met Office provide a validation of the data set used as seen in Figure 1 below.
Figure 1 – Met office and NOAA/NCEP reanalysis data used as forcing conditions for the model.
The mesh used for the modelling was optimized to provide a suitable representation of the features of interest in the storm and whilst starting out as a mesh of the entire North Atlantic for the entire duration of the storm system, this was reduced to a smaller North-East Atlantic model for a period including 3 days prior to the storm striking the South coast of the UK. This was to enable the wave model to be run in fully spectral mode, the most suitable for allowing the wind/wave generation and transport process to take place and at a computational speed that would be achievable for operational forecasting models (~1-2 hour model run times for combined wave and flow conditions).
Introduction
In February this year (2011) a large storm in the North Atlantic caused swell waves with periods of 20-25 seconds to propagate into the English Channel. Whilst this is not unusual in itself (beaches along the south coast have historically been subject to similar storms), the combination with high water of these small wave height, long period waves led to a series of flooding “near misses” along the South Coast as swell waves led to damage and overtopping of some defences including natural barrier beaches.
It is important to note that many of the beaches along the south coast are gravel/shingle dominated barriers which are typically considered reflective in morphological classifications (Short 1979). Greenwood (1984) noted that reflective beaches, which are already prone to sub-harmonic edge waves, can interact with longer period swell waves leading to an amplification of wave run up, a mechanism which leads to higher than anticipated overtopping and overwashing of the crest with consequent implications for barrier stability and hinterland flooding. With increasing emphasis from operating authorities being placed on beach management of such natural defences, it is important to understand the driving conditions in an event such as this to plan effective management.
With this in mind, DHI have developed a demonstration model of this event to show how the Flexible Mesh series of models allows you to take large scale North East Atlantic basin driving forces to understand the impact at a local scale. The coupled model developed makes use of the Spectral Wave and Hydrodynamic modules of the MIKE by DHI software and uses freely available data sources as inputs.
For this regionally focused modeling study, bathymetry data has been sourced from the GEBCO 08 Grid bathymetry data set which provides a 30 arc-second grid of the entire globe. Tidal data was obtained from the MIKE 21 toolbox to allow the flow model to be adequately resolved.
In addition the driving forces of the storm in the North East Atlantic needed to be represented. For this the NOAA/NCEP reanalysis data was used. This data set can provide driving wind fields and pressures for the entire globe and a temporal and spatial subset was utilized for this demonstration. The NOAA/NCEP reanalysis data is 6 hourly at a spatial resolution of 2.5 degrees. Available pressure charts from the UK Met Office provide a validation of the data set used as seen in Figure 1 below.
Figure 1 – Met office and NOAA/NCEP reanalysis data used as forcing conditions for the model.
The mesh used for the modelling was optimized to provide a suitable representation of the features of interest in the storm and whilst starting out as a mesh of the entire North Atlantic for the entire duration of the storm system, this was reduced to a smaller North-East Atlantic model for a period including 3 days prior to the storm striking the South coast of the UK. This was to enable the wave model to be run in fully spectral mode, the most suitable for allowing the wind/wave generation and transport process to take place and at a computational speed that would be achievable for operational forecasting models (~1-2 hour model run times for combined wave and flow conditions).
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