Generation and Modification of Computational Grids

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Revision as of 08:08, 22 June 2010 by imported>BAWiki 3

Remark: JANET covers many functions related to grid generation and grid modification.

This page gives you a comprehensive overview about all other programs actually used at BAW-DH for the purpose of grid generation and grid modification and with a functionality not covered by JANET.

Complex Workflows

Renewal of Bathymetry for Finite Difference Grids ([tr2.]topo.bin)

Graphical representation of the complex workflow concerning the renewal of bathymetry for various finite difference grids (filtype topo.bin and tr2.topo.bin). This figure is also available as a PostScript file.

Conversion between various Grid File Formats

Graphical representation of several existing conversion possiblities beetween different grid-file formats, also available as PostScript file.

Model-Independent Preprocessing

Modification and Display of Topographic Data

  • SYNGRID: Generation of artificial bearing data (e.g. along circles).
  • DATAUS: Selection of topographic data within an area defined by a surrounding polygon. This program is useful for many many topographic data points.

Boundary Polygon

IGEL2D: Interactive generation of a boundary polygon for a set of (selected) topographic data points.

Fairway Dredger Grid

TRASSE: Generation of nodal points for a fairway dredger grid. From these nodal points a FE-grid may be generated by means of triangulation.

Extraction of depth isolines

VOLUMETH: Extraction of depth isolines out of an FE grid (filetype gitter05.dat/bin).

Conversion of Grid Files

Several types of grid files are currently used at BAW-DH. The following file types are supported:

  1. FD-grid of type FIDISOR/FIDIRB
    filetype topo.bin.
  2. FD-grid of type TRIM
    filetype tr2.topo.bin. and tr2.topo.bin.ind.
  3. FE-grid of type TICAD
    filetype gitter05.dat/bin.
  4. FE-grid of type SELAFIN
    filetype selafin.

Graphic Display of Computational Grids

The following programs are currently available to display FE- and FD-grids:

Preprocessing for Finite Difference Models

The numerical models based on finite differences which are mainly used at BAW-DH are the two-dimensional model TRIM-2D as well as the three-dimensional model TRIM-3D. To generate the grid files for both aforementioned models several programs are can be used.

Generation of a Computational Grid

  • gridfile of type FIDISOR/FIDIRB:
  • FD2BASIS: generation of a basic FD-grid (filetype topo.bin) with correct land/water distribution from digitized boundary structures
  • TC2GEOM: generation of a FD-grid (filetype topo.bin) from a digital terrain model, which is based on a FE-grid (filetype gitter05.dat/bin).
  • TR2FIDI: generation of a FD-grid (filetype topo.bin) from an existing FD-grid (filetype tr2.topo.bin).
  • gridfile of type TRIM:

Manipulation of Computational Grids

  • gridfile of type FIDISOR/FIDIRB:
  • FD2CUT: Cutting a (small area) partial grid out of a complete grid.
  • FD2DEL: Calculating differences of bathymetry by comparing two existing bathymetries stored on two different FD-grids or, alternatively, modification of an existing bathymetry with earlier calculated differences of bathymetry.
  • FD2DTOP: Conversion for differences of bathymetry (generated by the program FD2DEL) into a FD-gridfile (filetype topo.bin).
  • FD2KACHEL: Cutting a small part of a grid from a complete gridfile, also in combination with numerically calculated results.
  • FD2MOD: Generation of modified differences of bathymetry out of regular differences of bathymetry which have been generated by the program FD2DEL before.
  • FDGLUE: Glue together two originally different grids to form one large new grid.
  • TOP2IN1: Insertion of a small grid into a large grid.
  • gridfile of type TRIM:
  • TR2KACHEL: Cutting a small part of a grid from a complete gridfile, also in combination with numerically calculated results.

Modification of Bathymetry

  • gridfile of type FIDISOR/FIDIRB:
  • FD2ADDTOPO: Update a FIDISOR/FIDIRB topography with data from echo soundings under constraints of digitized structures.
  • FD2BAGGER: Deepening of bathymetry (dredging of material).
  • FD2REM: Deletion of structures (e.g. groynes, dams) from a FD-grid.
  • FD2RIBA: Deepening of bathymetry (dredging of material), but taking into account the effect of dunes or deep areas.
  • FD2SPUELER: Reducing bathymetrical depths (disposal of material).
  • FD2WEVO: Inversion of the sign (from plus to minus or vice-versa) for the bathymetrical depths.
  • GEOMFD2: Generation of a grid out of a set of (representative) topographic data points. The format of the grid file is FIDISOR/FIDIRB (filetype topo.bin).
  • gridfile of type TRIM:
  • TR2REFRESH: Modify (refresh) bathymetry of a FD-grid with bathymetry given as a digital terrain model defined on an FE-grid (filetype gitter05.dat/bin). Different special actions are available to modify bathymetry, e.g. dredging or disposal of material.

Calculation of Volumes and Areas

  • gridfile of type FIDISOR/FIDIRB:
  • FD2HYPSO: Determination of the frequency distribution for bathymetrical depth of a FD-grid.
  • FD2DREV: Determination of dredged volumes.

Preprocessing for Finite Element Models

TELEMAC-2D is based on the finite element method and used at BAW-DH.

Generation of a Computational Grid

  • gridfile of type TICAD (gitter05.dat/bin):
  • GRIDCONVERT: Conversion from an existing grid file (filetype selafin).
  • JANET: Generation of an FE-grid out of point or polygon data or conversion from an existing grid file (filetypes [[SELAFIN|selafin], untrim_grid.dat and tr2.topo.bin are possible).
  • FD2GEOM: Generation of an FE-grid from an existing FIDISOR/FIDIRB grid (filetype topo.bin).
  • TR2GEOM: Generation of an FE-grid from an existing TRIM grid (filetype tr2.topo.bin).
  • gridfile of type SELAFIN (selafin):

Manipulation of Computational Grids

  • gridfile of type TICAD:
  • DIDASPLIT: Cutting of a grid into tiles, also in combination with calculated data stored in the well known BDF-Format (description available in German only).
  • KACHEL2D: Cutting a partial grid out of a complete grid.

Modification of Bathymetry

  • gridfile of type TICAD:
  • TC2BAGGER: Dredging and disposal of material.
  • UPDA2D: Modify bathymetric depths on a FE-grid using (selected) topographic data points.

Calculation of Volumes and Areas

  • gridfile of Type TICAD:
  • TOPVF: Calculation values for 2D- as well as 3D-areas which are lying in between two different horizontal planes.
  • VOLUMETH: Calculation of area distribution and volume sum function of a region inside an FE mesh.

Preprocessing for unstructured orthogonal grid Models

At BAW-DH we use an unstructured orthogonal grid method: UNTRIM. The grid generator JANET is fitted to the needs of this method. It is therefor no surprise that many grid functions useful for this method are integrated in JANET.

Generation of Grids (filetype untrim_grid.dat)

back to Pre- and Postprocessing