PARTRACE

Basic Information

Name of Program

PARTRACE

Version-Date

October 2011

Description-Date

October 2011

Catchwords

analysis of numerically calculated results (2D)
stochastic particle model
particle path
turbulent dispersion
sinking velocity
drift velocity
sediment transport

Short Description of Functionality

PARTRACE simulates the movement of particles with user-defined properties in a time-dependent 2D-depth-averaged flowfield, which has been computed e.g. with TRIM-2D, TELEMAC-2D or UNTRIM (two-dimensional, depth averaged results only). It is a tool for analyzing the motion of the water-body and the transport of sediments in estuarine flows. PARTRACE needs the flowfield data as direct access files of the type dirz.bin.r, dirz.bin.i and dirz.bin. In the input file partrace.dat the user specifies the number of particle-emitting sources, their location as well as number of particles to be tracked, seeding time intervall, and particle properties such as mass density, diameter, settling velocity, diffusion properties, ect.. The following influences on the particle motion are taken into account:

• 2D-depth-averaged velocity field
• vertical convergence or divergence of streamlines due to inclination of the seabed and of the water-level surface
• settling velocity
• random diffusion due to turbulence and dispersion due to depth-averaging of the velocity field
• constant particle drift velocity at the water surface

To the end of the simulation the history of particle locations is written to file insel.dat and can be visualized e.g. with HVIEW2D as pathlines in the domain.

Input-Files

1. general input data (filetype partrace.dat)
2. grid for 2D/3D-data (filetype gitter05.dat/bin or filetype untrim_grid.dat)
3. egde list of triangular grid (file type fkvz.bin)
4. neighbor element list of triangular grid (file type fkez.bin)
5. synoptic flow field results (filetype dirz.bin.r, dirz.bin.i, and dirz.bin)
6. (optional) initial location of particles, e.g. from a previous run (file name ftn41 on HP, or fort.41 on SGI)

Output-Files

1. particle paths (file insel.dat)
2. for the first 4 particles, ascii-files containing:
   • z-coordinates of particle, of the seabed and of the water-level surface, the ladder at the paticle location, respectively, as function of time (file names ftn21, ftn22,

   ftn23, ftn24 on HP, or fort.21, ... on SGI)

   • the 3 velocity components of the particle as a function of time (file names ftn31, ftn32, ftn33, ftn34 on HP, or fort.31, ... on SGI)
3. printer file (filetype partrace.sdr)
4. (optional) trace of program execution (filetype partrace.trc)

Methodology

To capture the effect of the depth-averaged velocity field, its components U and V at the 3 nodes of the triangle where the particle is currently located in, at time instances before and after the current simulation time, are made available. These data are linearly interpolated to the current simulation time and bilinearly interpolated onto the location of the particle. The motion of the particle in the 3 spatial directions is described by 3 coupled ordinary differential equations (ODEs) in time. They contain the interpolated velocity components and terms that characterize the other physical effects listed above. The system of ODEs is solved stepwise using a standard-Runge-Kutta method (see Numerical Recipes). This finally yields the path of a particle in the flowfield. More information about PARTRACE is given in The Mathematical Model PARTRACE. A thorough documentation of the physical modelling used its features can be found in the Programmbeschreibung des Partikelverfahrens PARTRACE (currently in german only, sorry!).

Program(s) to run before this Program

DATACONVERT, TELEMAC-2D, TR2DIDA, TM2DIDA, UNTRIM

Program(s) to run after this Program

HVIEW2D, davit, xmgr

Additional Information

Language

Fortran 95, partly C

Additional software

-

Original Version

F. Bergemann

Maintenance

H. Weilbeer, G. Seiß

Documentation/Literature

please refer to $PROGHOME/examples/partrace/

Download the program description (in german language only) as PDF-file partrace.pdf

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