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Difference between pages "Tidal Characteristic Numbers of Suspended Sediment Transport" and "Mathematical Model TRIM-2D"

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(Difference between pages)
imported>Lang Guenther
(Flood Current: transport als well as transport rate of suspended load added)
 
imported>BAWiki 1
 
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[[category:Tidal Characteristic Numbers]]
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[[Category: Mathematical Models]]
[[de: Tidekennwerte des Schwebstoffgehalts]]
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[[de: Mathematisches Verfahren TRIM-2D]]
[[Tidal Characteristic Numbers of Salinity|graphical representations of the characteristic numbers of salinity]]
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==Short Description==
==Motivation==
+
The mathematical model TRIM-2D is based on the finite difference method. TRIM-2D was designed to solve several depth-integrated transient nonlinear partial differential equations (pde's). The model is actually used to study one ore more of the following physical processes:
The calculation as well as the graphic visualization of various tidal characteristic numbers of suspended sediment concentration and also for the advective transport of suspended sediment contributes to an improved understanding of tidally dominated transport processes in estuaries. Spatial variations of suspended sediment concentration, advective transport of suspended sediment by means of flood and ebb currents can be highlighted for areas like coastal seas and estuaries as well.
 
* As the calculations are performed separately for the durations of ebb- and flood-current it can be shown that transport paths can differ significantly for the two tidal phases. From this one can get additional insight with respect to the relevant transport mechanisms dominated by the tidal currents. This can be related to locally varying flood-ebb asymmetries for ebb volume and flood volume. Also the presence of horizontal gradients can contribute to this effect.
 
* The variation of suspended sediment concentration resulting from the local maximum as well as the local minimum of suspended sediment concentration can be quite large. This is a consequence of the different availability of suspended sediments, e. g. inside or outside of the turbidity maximum. The value for the local suspended sediment concentration variation is mainly the result of the product between the horizontal suspended sediment concentration gradient and the lagrangian drift of a water particle during a complete tidal cycle, but also effected by the strong spatial variation of deposition and erosion of suspended sediments throughout the estuary.
 
  
An automatic analysis of all tidal characteristic numbers of suspended sediment transport is carried through by the computer programs [[TDKSF]] and [[NCANALYSE]].
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# transport of water (conservation of the water mass)
 
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# transport of linear momentum (conservation of linear momentum)
==Definitions for the Tidal Characteristic Numbers of Suspended Sediment Transport==
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# transport of salinity (conservation of the dissolved salt mass)
 
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# transport of suspended sediments with consideration of resuspension and deposition at the bottom (conservation of the suspended sediment mass)
===Program [[NCANALYSE]]===
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# bed load transport (a transport capacity approach is used)
 
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# evolution of the bottom (morphodynamics) due to suspended load as well as bed load transport
====Flood Current====
 
 
 
=====Advective Flood Transport of Suspended Load=====
 
Exact amount of suspended load (with exception of roundoff) which passes a certain cross section during flood current due to advection. This quantity makes use of the normal flow of suspended load only, which is orthogonal to the flow face. Reconstruction of the total vector by means of projection is left to visualization programs (e. g. [[NCPLOT]]).
 
 
 
=====Diffusive Flood Transport of Suspended Load=====
 
Exact amount of suspended load (with exception of roundoff) which passes a certain cross section during flood current due to (turbulent) diffusion. This quantity makes use of the normal flow of suspended load only, which is orthogonal to the flow face. Reconstruction of the total vector by means of projection is left to visualization programs (e. g. [[NCPLOT]]).
 
 
 
=====Advective Flood Transport-Rate of Suspended Load=====
 
Exact transport rate of suspended load (with exception of roundoff) which passes a certain cross section during flood current due to advection. This quantity makes use of the normal flow of suspended load only, which is orthogonal to the flow face. Reconstruction of the total vector by means of projection is left to visualization programs (e. g. [[NCPLOT]]). On tidal flats this quantity is computed for the period of inundation only.
 
 
 
=====Diffusive Flood Transport-Rate of Suspended Load=====
 
Exact transport rate of suspended load (with exception of roundoff) which passes a certain cross section during flood current due to (turbulent) diffusion. This quantity makes use of the normal flow of suspended load only, which is orthogonal to the flow face. Reconstruction of the total vector by means of projection is left to visualization programs (e. g. [[NCPLOT]]). On tidal flats this quanmtity is computed for the period of inundation only.
 
 
 
=====Mean Suspended Load Flood Current=====
 
Mean value of suspended load during flood current duration of a tide.<br />
 
<!-- [[Example figures: Mean suspended load flood current]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
====Ebb Current====
 
 
 
=====Mean Suspended Load Ebb Current=====
 
Mean value of suspended load during ebb current duration of a tide.<br />
 
<!-- [[Example figures: mean suspended load ebb current]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
====Tidal Cycle====
 
 
 
=====Maximum Suspended Load=====
 
Maximum value of suspended load during a full tidal cycle (period between two subsequent slack water times of ebb current).<br />
 
<!-- [[Example figures: maximum suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Minimum Suspended Load=====
 
Minimum value of suspended load during a full tidal cycle (period between two subsequent slack water times of ebb current).<br />
 
<!-- [[Example figures: minimum suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Mean Suspended Load=====
 
Average value of suspended load during a full tidal cycle (period between two subsequent slack water times of ebb current).<br />
 
<!-- [[Example figures: mean suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Tidal Variation of Suspended Load=====
 
Difference between maximum and minimum values of suspended load during a full tidal cycle (period between two subsequent slack water times of ebb current).<br />
 
<!-- [[Example figures: tidal variation of suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Mean Suspended Load Flood Current : Mean Suspended Load=====
 
Ratio between mean suspended load during flood current and mean suspended load during the full tidal cycle.<br />
 
<!-- [[Example figures: mean suspended load flood current : mean suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Mean Suspended Load Ebb Current : Mean Suspended Load=====
 
Ratio between mean suspended load during ebb current and mean suspended load during the full tidal cycle.<br />
 
<!-- [[Example figures: mean suspended load ebb current : mean suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Mean Suspended Load Flood Current : Mean Suspended Load Ebb Current=====
 
Ratio between mean suspended load during flood current and mean suspended load during ebb current.<br />
 
<!-- [[Example figures: mean suspended load flood current : mean suspended load ebb current]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Tidal Variation of Suspended Load : Mean Suspended Load=====
 
Ratio between tidal variation of suspended load and mean suspended load during the tidal cycle.<br />
 
<!-- [[Example figures: tidal variation of suspended load : mean suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Maximum Suspended Load : Mean Suspended Load=====
 
Ratio between maximum suspended load and mean suspended load during the tidal cycle.<br />
 
<!-- [[Example figures: maximum suspended load : mean suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
=====Minimum Suspended Load : Mean Suspended Load=====
 
Ratio between minimum suspended load and mean suspended load during the tidal cycle.<br />
 
<!-- [[Example figures: minimum suspended load : mean suspended load]]. <br /> -->
 
Data analysis: [[NCANALYSE]].
 
 
 
===Program [[TDKSF]]===
 
 
 
====Flood Current====
 
 
 
=====Advective Flood Transport of Suspended Sediment=====
 
 
 
Suspended sediment mass, which is transported by means of flood current through a cross section<br />
 
Example: not available.
 
 
 
====Ebb Current====
 
 
 
=====Advective Ebb Transport of Suspended Sediment=====
 
 
 
Suspended sediment mass, which is transported by means of ebb current through a cross section<br />
 
Example: not available.
 
 
 
====Tidal Cycle====
 
 
 
=====Maximum Suspended Sediment Concentration=====
 
 
 
Maximum value of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)<br />
 
Example: not available.
 
 
 
=====Minimum Suspended Sediment Concentration=====
 
 
 
Minimum value of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)<br />
 
Example: not available.
 
 
 
=====Mean Suspended Sediment Concentration=====
 
 
 
Average value of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)<br />
 
Example: not available.
 
 
 
=====Tidal Variation of Suspended Sediment Concentration=====
 
 
 
Difference between the extreme values of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)<br />
 
Example: not available.
 
 
 
=====Advective Residual Transport of Suspended Sediment=====
 
 
 
Residual suspended sediment mass which is transported by means of ebb and flood currents through a cross section (the different transport directions are taken into account). If the advective transport by means of flood current is equal but in opposite direction of the ebb current transport this will result in a zero advective residual transport of suspended sediment.<br />
 
Example: not available.
 
 
 
=====Advective Suspended Sediment Transport, Flood-Ebb-Ratio=====
 
 
 
Flood to ebb ratio for the suspended sediment volumes which are transported by means of flood and ebb currents<br />
 
Example: not available.
 
  
 +
TRIM-2D was jointly developed by Prof. V. Casulli (Trento University, Italy) as well as Prof. R. T. Cheng (US Geological Survey, Menlo Park, California). In the framework of a scientific cooperation TRIM-2D has been successfully installed in the year 1994 at BAW-DHs computers. It has been integrated into BAW-DHs numerical modelling toolbox and is now used on a routine basis in the context of different real-world projects concerning estuarine flow and transport processes. Meanwhile the capabilities of the model were extended and new physical processes have been included.
 +
Furthermore the program was parallelized using [http://openmp.org/wp/ OpenMP]-directives for SMP ([http://burks.brighton.ac.uk/burks/foldoc/5/114.htm symmetric multiprocessing]) systems in a portable way.
 +
==Standard Validation Document==
 +
There exists a Standard Validation Document (in German only) for TRIM-2D which provides the potential user with information about the capabilities and limitations of the model. This document may be downloaded either as [http://www.baw.de/downloads/wasserbau//mathematische_verfahren/Modellverfahren/pdf/trim2d1.pdf PDF-Version] ( 2.1M) or as a compressed PostScript-Version  ( 2.9M).
 +
==Preprocessors==
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* [[Generation of Boundary Conditions]]
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* [[Generation and Modification of Computational Grids]]
 +
==Programs for Simulations==
 +
* [[TR2VOR]]: generation of a compact version of the bathymetry-file together with some index arrays which are required during the simulation run for optimal performance on vector computers
 +
* [[TR2LQ2]]: generation of a profile topography which is necessary to output results from a TRIM-2D simulation run along profiles
 +
* [[TRIM-2D]]: simulation run
 +
==Postprocessors==
 +
* [[Conversion of Computed Results]]: general purpose prostprocessors for the conversion of data.
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* [[Analysis of Calculated Results]]: tidal characteristic numbers, tide-independent characteristic numbers, tidal harmonic analysis and comparative analysis.
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* [[EXCEL-Applications|Spread-Sheet Calculations for Computed Results]]: application of the spread-sheet program MS Excel (TM) to display and modify computed results.
 +
* [[TR2MODATE]]: modification of date and time in a hydrodynamic results file if this hydrodynamic state should be used as initial state for a different date
 +
* [[TR2KACHEL]]: generation of sections (tiles); topography as well as data are cut into pieces out of the result files for the entire computational domain for any desired section (tile)
 +
* [[PARTRACE]]: particle tracking within a two-dimensional depth-averaged velocity field
 +
* [[GVIEW2D]]: graphical display of time series at selected locations
 +
* [[LQ2PRO]]: Visualization of data along profiles
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* [[HVIEW2D]]: graphical display of 2D synoptic or data analyses results
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* [[VVIEW2D]]: Two-dimensional graphical representation of CFD-data for vertical sections
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==Example Applications==
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* [[Hydrodynamics of the Elbe Estuary]]: A comprehensive study concerning hydrodynamics, salt- and bedload transport in the Elbe Estuary.
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* [[Suspended Sediment Transport]]: Demo-Example (available in German only).
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* [[Animation of tidal variability of salinity in the Außenweser Estuary]].
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* [[Animation of Water Level Elevation and Flow Velocity in the Inner Jade estuary]].
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* [[Tidal characteristic numbers of current velocity for the Weser Estuary]].
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* [[Tidal characteristic numbers of salinity for the Weser Estuary]].
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* [[Modeling the propagation of dunes]] in a straight channel (available in German only).
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* [[Animation of vortex streets behind a planned storm surge barrier in the Unterems]].
 
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back to [[Analysis of Calculated Results]]
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back to [[Mathematical Models for Coastal Areas and Estuaries]]
 
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[[Overview]]
 
[[Overview]]

Revision as of 07:53, 21 June 2010

Short Description

The mathematical model TRIM-2D is based on the finite difference method. TRIM-2D was designed to solve several depth-integrated transient nonlinear partial differential equations (pde's). The model is actually used to study one ore more of the following physical processes:

  1. transport of water (conservation of the water mass)
  2. transport of linear momentum (conservation of linear momentum)
  3. transport of salinity (conservation of the dissolved salt mass)
  4. transport of suspended sediments with consideration of resuspension and deposition at the bottom (conservation of the suspended sediment mass)
  5. bed load transport (a transport capacity approach is used)
  6. evolution of the bottom (morphodynamics) due to suspended load as well as bed load transport

TRIM-2D was jointly developed by Prof. V. Casulli (Trento University, Italy) as well as Prof. R. T. Cheng (US Geological Survey, Menlo Park, California). In the framework of a scientific cooperation TRIM-2D has been successfully installed in the year 1994 at BAW-DHs computers. It has been integrated into BAW-DHs numerical modelling toolbox and is now used on a routine basis in the context of different real-world projects concerning estuarine flow and transport processes. Meanwhile the capabilities of the model were extended and new physical processes have been included. Furthermore the program was parallelized using OpenMP-directives for SMP (symmetric multiprocessing) systems in a portable way.

Standard Validation Document

There exists a Standard Validation Document (in German only) for TRIM-2D which provides the potential user with information about the capabilities and limitations of the model. This document may be downloaded either as PDF-Version ( 2.1M) or as a compressed PostScript-Version ( 2.9M).

Preprocessors

Programs for Simulations

  • TR2VOR: generation of a compact version of the bathymetry-file together with some index arrays which are required during the simulation run for optimal performance on vector computers
  • TR2LQ2: generation of a profile topography which is necessary to output results from a TRIM-2D simulation run along profiles
  • TRIM-2D: simulation run

Postprocessors

  • Conversion of Computed Results: general purpose prostprocessors for the conversion of data.
  • Analysis of Calculated Results: tidal characteristic numbers, tide-independent characteristic numbers, tidal harmonic analysis and comparative analysis.
  • Spread-Sheet Calculations for Computed Results: application of the spread-sheet program MS Excel (TM) to display and modify computed results.
  • TR2MODATE: modification of date and time in a hydrodynamic results file if this hydrodynamic state should be used as initial state for a different date
  • TR2KACHEL: generation of sections (tiles); topography as well as data are cut into pieces out of the result files for the entire computational domain for any desired section (tile)
  • PARTRACE: particle tracking within a two-dimensional depth-averaged velocity field
  • GVIEW2D: graphical display of time series at selected locations
  • LQ2PRO: Visualization of data along profiles
  • HVIEW2D: graphical display of 2D synoptic or data analyses results
  • VVIEW2D: Two-dimensional graphical representation of CFD-data for vertical sections

Example Applications


back to Mathematical Models for Coastal Areas and Estuaries


Overview