UNTRIM
From BAWiki
Basic Information
Name of Program
UNTRIM
VersionDate
2.x / April 2005
DescriptionDate
November 2013
Catchwords
numerical simulation
finite difference method
finite volume method
unstructured orthogonal grid
twodimensional, threedimensional
unsteady, nonlinear
hydrostatic, nonhydrostatic
reynoldsaveraged Navier Stokes equations (RANS)
tidal dynamics (long waves)
wave propagation (short waves, wave spectrum)
transport of conservative tracers (salt, temperature, suspended sediments)
numerical method UNTRIM
morphodynamic submodel SEDIMORPH
portable SMPprogramming using OpenMP
Short Description of Functionality
Method
The threedimensional finite difference / finite volume numerical model UNTRIM can be used to simulate flow and transport processes in different freesurface flow problems. In contrast to conventional finite difference methods UnTRIM is able to operate on an unstructured orthogonal grid.
Physical Processes
The following physical processes are currently taken into account by UNTRIM:
 reynoldsaveraged NavierStokes equations (RANS)
 local acceleration (inertia)
 advective acceleration
 Coriolis acceleration
 barotropic pressure gradient
 baroclinic pressure gradient
 hydrostatic or nonhydrostatic pressure
 horizontal turbulent viscosity
 vertical turbulent viscosity influenced by density stratification
 bottom friction
 wind friction
 sources and sinks
 transport of tracers
 local rate of change of concentration
 advective rate of change of concentration
 optional flux limiter : Minmod, van Leer or Superbee
 horizontal turbulent diffusivity
 vertical turbulent diffusivity influenced by density stratification
 settling of particles, deposition and erosion (for suspended sediments)
 sources and sinks
 sinks with immediate return inflow at a different location, with optional modification of inflowtemperature as well as salinity
Computational Results
 free surface elevation
 current velocity
 concentration of tracers (e.g. salinity, temperature, suspended load)
 vertical turbulent eddyviscosity
 hydrodynamic pressure
 water density
If a threedimensional simulation is carried through the depthaveraged results are also computed in addition to the threedimensional ones.
Validation Document
A PDFversion of the validation document is freely available for download:
 (approx. 1.2 MB) UNTRIM standard validation document
additional physical submodels The numerical method UnTRIM is coupled to the following (independent) physical submodels:
 morphodynamic computational package SediMorph: for details please refer to sedimorph.dat.
 spectral wave model kmodel: for details please refer k_model.dat
InputFiles
 main input data (filetype untrim_main.dat).
 Hydrodynamics and Salt Transport (filetype untrim_hyd.dat);
 Atmosphere (filetype untrim_atm.dat);
 BedloadTransport (filetype untrim_bed.dat);
 Equation of State (filetype untrim_eqs.dat);
 Morphodynamic Evolution (filetype untrim_mor.dat);
 Suspended Sediment Transport (filetype untrim_sus.dat);
 Wind Waves (filetype untrim_wav.dat).
Notice: further input files can be found on the file description pages of the aforementioned files.
OutputFiles
the number and type of result files does mainly depend on the output parameters chosen for the different physical sub models. Typically the following types of files will be generated:
 file with modified computational grid (filetype untrim_grid.dat);
 Notice: this (modified) system file must be used during postprocessing of computational results in the overall domain;
 (optional) file with modified profile topography (filetype profil05.bin);
 Notice: this (modified) profile topography must be used during postprocessing of computational results along profiles;
 (optional) system file for specific locations (filetype location_grid.dat);
 Notice: this system file must be used for postprocessing of results generated for specific locations.
 (optional) computational results for the overall domain, at specific locations or along profiles (filetype dirz.bin.r, dirz.bin.i and dirz.bin);
 (optional) restart files, which are necessary for a later continuation of the simulation (filetype dirz.bin.r, dirz.bin.i and dirz.bin);
 (optional) informative printer file (Dateityp untrim_main.sdr);
 (optional) trace of program execution (filetype untrim_main.trc).
 message file (filetype untrim.msg); parts of this file can be visualised and processed using UNTRIMMONITOR.
Methodology
please refer to documentation/literature
Program(s) to run before this Program
GRIDCONVERT, GVIEW2D, JANET, RSMERGE, TICLQ2, TOUTR, UTRRND
Program(s) to run after this Program
ABDF, ADCP2PROFILE, DIDAMERGE, DIDAMINTQ, DIDAMINTZ, DIDARENAME, DIDASPLIT, ENERF, GRIDCONVERT, GVIEW2D, HVIEW2D, IO_VOLUME, LQ2PRO, NCVIEW2D, PARTRACE, PGCALC, PLOTPROFILZEIT, PLOTTS, QUICKPLOT, RSMERGE, TIMESHIFT, UNS, UNTRIMMONITOR, VTDK, VVIEW2D, XTRDATA, XTRLQ2, ZEITR
Additional Information
Language
Fortran90
Additional software

Original Version
Maintenance
Documentation/Literature
 please refer to $PROGHOME/examples/untrim/
 ./BSP_becken_src_snk/ : example files for a closed basin with one sink and one source.
 ./BSP_becken_wind/ : example files for wind influence on water level elevation and current velocity in a closed basin.
 ./BSP_hafen/ : example files for wave propagation in a harbour basin.
 ./BSP_kanal_w_gradient/ : example files for a straight channel with constant water level gradient;
 ./BSP_kanal_w_inflow/ : example files for a straight channel with constant inflow (discharge).
 ./BSP_kanal_salt_heat/ : example files for a straight channel with outtakeinflow situation, additionally taking alterations of inflowtemperature and salinity into account.
 ./BSP_soliton / : propagation of a solitary wave in a straight wave channel.
 Casulli, Vincenzo and Roy A. Walters (2000), An unstructured, threedimensional model based on the shallow water equations, International Journal for Numerical Methods in Fluids 2000, 32: 331  348.
 see also numerical model UNTRIM.
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