TRIM-2D

Basic Information

Name of Program

TRIM-2D

Version-Date

12.x

Description-Date

March 2003

Catchwords

numerical simulation
finite difference method
two-dimensional, transient, nonlinear
shallow water equations
tidal dynamics
advection-diffusion equation
salt transport
suspended sediment transport
deposition and resuspension
bed load transport
numerical model TRIM-2D
portable SMP-programming using OpenMP
morphodynamic evolution of the bottom due to suspended load as well as bed load transport

Short Description of Functionality

The two-dimensional finite difference numerical model TRIM-2D can be used to simulate flow and transport processes in different free-surface flow problems. The following list of physical processes are taken into account by TRIM-2D:

shallow water equations

local acceleration (inertia)
advective acceleration
Coriolis acceleration
barotropic pressure gradient
baroclinic pressure gradient (depth integrated)
turbulent diffusion and dispersion
bottom friction
wind friction
time-varying height of control-structures (weirs)

advection-diffusion equation

local rate of change of concentration
advctive rate of change of concentration
turbulent diffusion and dispersion
settling velocity depends on turbulence intensity

Exchange of suspended sediments between the bottom layer and the water column

resuspension of deposited suspended sediments above a critical bottom shear stress (critical shear stress for resuspension)
deposition of suspended sediments below a critical bottom shear stress (critical shear stress for deposition)

bed load transport of sediments

bed load transport rate is given by the transport capacity of the flow (vanRIJN, BAGNOLD)

morphodynamic evolution of the bottom

net erosion/deposition due to bed load transport
net erosion/deposition due to suspended load transport

Turbulent diffusion as well as dispersion is parameterized using constant coefficients.

With the aid of the numerical model TRIM-2D the following physical quantities can be calculated:

free surface elevation
depth-averaged current velocity
depth-averaged salinity
depth-averaged suspended sediment concentration
deposited suspended sediment mass
bed load transport rate
deposited bed load material mass
bottom shear stress
wind shear stress
depth erosion
time varying depth of the bottom

A comprehensive description of TRIM-2D is available in the form of a Standard Validation Document (in German only).

Input-Files

general input data (filetype trim2d.dat)
general input data for bed load transport (filetype trim2d.bed.dat)
solver accuracy (filetype relax.dat)
bathymetry and index arrays (filetype tr2.topo.bin.ind)
boundary values file for hydrodynamics (filetype tr2.rbh.bin.I and filetype tr2.rbh.bin)
(optional) boundary values file for salinity (filetype tr2.rbs.bin.I and filetype tr2.rbs.bin)
(optional) boundary values file for suspended sediment concentration (filetype tr2.rbc.bin.I and filetype tr2.rbc.bin)
(optional) control structure boundary condition file (filetype tr2.rbw.bin.I and filetype tr2.rbw.bin)
(optional) wind field (filetype tr2.met.bin.I and filetype tr2.met.bin)
(optional) description of soil types (filetype soil.dat)
(optional) distribution of soil types (filetype tr2.soil.bin.ind)
(optional) initial conditions (filetype tr2.result)
TR2first_H: hydrodynamics, depth of the bottom

TR2first_S: salinity

TR2first_C: suspended sediment concentration

TR2first_B: deposited suspended sediments

TR2first_L: bed load transport rate and deposited bed load material
(optional) profile-topography (filetype profil05.bin)

Output-Files

computational results at the end of the simulation (filetype tr2.result)
TR2last_H: hydrodynamics, depth of the bottom

TR2last_S: salinity

TR2last_C: suspended sediment concentration

TR2last_B: deposited suspended sediments

TR2last_L: bed load transport rate and deposited bed load material

TR2last_A: optional results (e.g. wind shear stress, bottom shear stress)
(optional, in case of morphodynamic simulation) final bathymetry and index arrays (filetype tr2.topo.bin.ind)
(optional) results files (filetype tr2.result)
(optional) time series of computed results at specific locations (filetype knoerg.bin)
(optional) computed results along profiles (files of type dirz.bin.R, dirz.bin.I and dirz.bin)
(optional) safety output of computational results at regular intervals (filetype tr2.result)
TR2save_H: hydrodynamics, depth of the bottom

TR2save_S: salinity

TR2save_C: suspended sediment concentration

TR2save_B: deposited suspended sediments

TR2save_L: bed load transport rate and deposited bed load material

TR2save_A: optional results (e.g. wind shear stress, bottom shear stress)
printer file with informations about essential parameters used and informative messages during program execution (filetype trim2d.echo)
(optional) trace of program execution (filetype trim2d.trc)