HARDNESS, FRACTURE TOUGHNESS AND STRENGTH OF CERAMICS
Applying Unstructured Grid Model for Tides in the Belgian Continental Shelf
1. Applying Unstructured Grid Model for Tides in the Belgian Continental Shelf
02.09.2015 / Brussels
Promotor : Professor Dr. ir. M. Chen
Advisor : Dr. Olivier Gourgue
By : Biniyam Sishah
02.09.2015 / Brussels
3. Content
Introduction
Method and Material
Results and Discussion
Conclusion and RecommendationConclusion and Recommendation
Results and Discussion
General
Modeling of Tides
Preliminary Work
Study Area
Objectives
Introduction
Method and Material
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4. General
Tides are the vertical rise and fall of
the water surface in oceans due to
phases of the moon and sun.
Source: https://en.wikipedia.org/wiki/Tide
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5. General
Tides are the vertical rise and fall of
the water surface in oceans due to
phases of the moon and sun.
Source: https://en.wikipedia.org/wiki/Tide
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Various interactions causes tidal
variations at a location.
6. General
Tides are the vertical rise and fall of
the water surface in oceans due to
phases of the moon and sun.
Source: https://en.wikipedia.org/wiki/Tide
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Various interactions causes tidal
variations at a location.
Corresponding tidal variations(level
and Currents) are expressed by a
collection sum of simple sinusoid
curves called Tidal constituents
(𝑨, 𝝋,W).
𝑨 = Amplitude
𝝋 = Phase
w= angular velocity
7. Modeling of tides
SWE derived from the 3D Navier-stokes equations are often used in models.
These equations has no analytical solutions.
FEM(finite elements method) with unstructured grids were used for this work.
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8. Generation of the Unstructured Grid
Setting up of Telemac2D model
Mesh refinement has been performed
in some locations.
Preliminary work
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Source :Flanders Hydraulic research Center
9. Generation of the Unstructured Grid
Setting up of Telemac2D model
Mesh refinement has been performed
in some locations.
Preliminary work
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Source :Flanders Hydraulic research Center
10. Study area : what do we know?
The Belgium Continental Shelf (BCS)
Surface area: 191 Km2
Offshore length:76.2 Km
Gullies and sand bank formations
High turbidity near Coastlines
Presence of Scheldt Estuary
The bathymetry of the Belgium shelf [source:(Anon, n.d.) ]
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11. Objective
The main objective was to reproduce the tidal movement in the Belgium continental
shelf area. In the context of this work the following specific objectives were
accomplished:
Selection of Calm and Stormy wind periods
Calibration of the Telemac2D model for Tide levels
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12. Content
Introduction
Method and Material
Results and Discussion
Conclusion and Recommendation
Introduction
Conclusion and Recommendation
Methodology
Materials and Data
Method and Material
Results and Discussion
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13. Methodology
Matlab
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1. Selection of wind periods:
2 . Calibration of Model
Criteria CFG-1 CFG-2
Coordinate of Unstructured grid mesh Cartesian coordinates
Telemac2D projection system Mercator UTM 31N
Tide generating force YES Not Available
Spherical coordinates YES Not Available
Coriolis coefficients Actual value at a Node Constant value
Telemac2D
(future work)
14. Materials and Data
Materials Data
Telemac2D
Matlab
Others…
European shelf tidal dataset
(OTIS regional tidal solutions) Observations stations
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15. Content
Introduction
Method and Material
Results and Discussion
Conclusion and Recommendation
Method and Material
Introduction
Conclusion and Recommendation
Results and Discussion Wind period selection
Boundary condition
Bottom Friction
Models’ Performance In the BCS
Model performance (Local scale )
Temporal scale of errors
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16. Wind period selection
Calm period: July => used for tidal calibration
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Satellite Measurements Observation station
17. Wind period selection
Calm period: July => used for tidal calibration
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Satellite Measurements Observation station
21. Bottom friction
Sensitivity analysis for Manning’s and chezy’s formulations
CFG-2 had a better performance at Manning’s Coff.=0.024 and Chezy’s Coff. =56
Legend
Chezy's formulation
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Manning's formulation
22. Bottom friction
Sensitivity analysis for Manning’s and chezy’s formulations
CFG-2 had a better performance at Manning’s Coff.=0.024 and Chezy’s Coff. =56
Legend
Chezy's formulation
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Manning's formulation
23. Bottom friction
Sensitivity analysis for Manning’s and chezy’s formulations
CFG-2 had a better performance at Manning’s Coff.=0.024 and Chezy’s Coff. =56
Legend
Chezy's formulation
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Manning's formulation
24. Bottom friction
Sensitivity analysis for Manning’s and chezy’s formulations
CFG-2 had a better performance at Manning’s Coff.=0.024 and Chezy’s Coff. =56
Legend
Chezy's formulation
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Manning's formulation
25. Bottom friction
Spatial plots of Relative Harmonic errors over BCS( Sea-surface level of CFG-2)
Except a difference in their weightage areas, convey similar information.
Highest error value were achieved near the Scheldt Estuary ?
Manning's Coefficient Chezy’s Coefficient
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27. Model performance (Local scale)
How is Model’s performance In different locations?
Model performs is better in deep waters than Coastal locations.
Model Performance is better in the BCS than other similar Coastal locations.
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28. Model performance (Local scale)
How is Model’s performance In different locations?
Model performs is better in deep waters than Coastal locations.
Model Performance is better in the BCS than other similar Coastal locations.
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29. Temporal scale of errors (Goodness of fit tests)
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Amplitudes=>(Observ. ≈CFG-2)
Phases=> (Observ. ≈ OTIS)
30. Temporal scale of errors (Goodness of fit tests)
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Amplitudes=>(Observ. ≈CFG-2)
Phases=> (Observ. ≈ OTIS)
31. Temporal scale of errors (Goodness of fit tests)
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Amplitudes=>(Observ. ≈CFG-2)
Phases=> (Observ. ≈ OTIS)
32. Temporal scale of errors (Goodness of fit tests)
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Amplitudes=>(Observ. ≈CFG-2)
Phases=> (Observ. ≈ OTIS)
33. Temporal scale of errors (Goodness of fit tests)
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Amplitudes=>(Observ. ≈CFG-2)
Phases=> (Observ. ≈ OTIS)
35. Conclusion
Boundary conditions for Sea Surface level were properly set.
Optimum model setup: UTM 31N (CFG-2) projection with either Manning’s
(0.024) and Chezy’s (56) coefficient.
CFG-2 has a good performance with tide levels but not tidal currents.
Mesh refinement in the BCS have increased model performance
There is high probability that the calibrated Teleamac2D model here, might
perform better than OTIS in the BCS. ( with further work)
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36. Recommendation
Present
Boundary nodes of U and V velocity should be modified.
Simulations considering different parameter values for BCS and Scheldt Estuary
should be made in model.
Telemac2D model setup of CFG-1 should be investigated for bugs.
Future
Including downstream River influences near the Scheldt Estuary.
Using lower model domain area.
Simulation with Telemac3D
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