Frequently Asked Questions

MIKE 21/3 PT

Please do not hesitate to e-mail us if you have questions and/or answers yourself: mikebydhi@dhigroup.com.


 

    Entered: 2008-5-13
  • Question:

    Environment: New output options in MIKE 21 and MIKE 3 Particle Tracking


    Answer:

    In Release 2008 SP2 it is possible to define output features that are not available from the PT Model Editor.
    These output types resemble some of the types available in the MIKE 21/3 PA model.

    By defining various variables in the input file using an ASCII editor it is possible to obtain the following additional output features for each output area and class.

    2D Output can now be specified in simulations based on both dfs2 and dfs3 hydrodynamics. The 2D Output can be obtained with a finer resolution than in the input hydrodynamic files, and new additional output items are available:

      1.  Class concentration
      2.  Suspended class concentration
      3.  Sedimented class concentration
      4.  Class concentration in z range

    To include the new 2D output features the following specifications must be written in the output file:



    1. The output file name must have extension .dfs2, when specifying 2D output. If the hydrodynamic files have the format .dfs3, the parameter filedim=2 must also be specified.

    2. A finer gridspacing is obtained by specifying e.g. the parameter
    resfactor = -2, which in this case gives a refined grid output where DX=DXold/2

    3. To include an output item for volume concentration of suspended material for e.g. class 1 in entire water column (kg/m^3), the following parameter must be specified:
    SUSP_CLASS_1 = 1

    4. To include an output item for volume concentration of sedimented material for e.g. class 1 (kg/m^2), the following parameter must be specified:
    SEDI_CLASS_1 = 1
    (This corresponds to the accumulated net sedimentation in MIKE 21/3 PA)

    5. To include an output item for volume concentration of material in defined z-range (kg/m^3), the following paramters must be specified:
    ZRANGE_CLASS_1 = 1
    upperz = 0 
    lowerz = -1.0 
    The given example definition outputs the volume concentration in the upper 1 m of the water column.  

     

    Pls. note that the additional 2D hydrodynamic output parameters can not be included in the same output file that contains the above features.

    The modified input file must then be executed by using the Launch Simulation Engine.

    PLEASE NOTE: if you open the modified input file in PT Editor at a later stage, your modifications to the input file may be lost.


    Below is an example of a customized input file for a 3D case with two classes: The second output is given in a refined grid where DX=DXold/3, the concentration of suspended material and mass of sedimented material are stored for each class as well as the concentration in a layer located between 1.5 m and 3.5 m below the water surface.







    [OUTPUT_2]
          Touched = 1
          include = 1
          title = 'Output 2'
          datatype = 1
          file_name = 'Concentration.dfs2'
          area = 1
          
    filedim = 2
         
    resfactor = -3
         
    upperz = -1.5
         
    lowerz = -3.5
          first_time_step = 0
          last_time_step = 750
          time_step_frequency = 10
          [PARAMETERS_2D]
              Touched = 0
              CLASS_1 = 1
              CLASS_2 = 1
              SURFACE_ELEVATION = 0
              STILL_WATER_DEPTH = 0
              TOTAL_WATER_DEPTH = 0
              DEPTH_AVERAGE_U_VELOCITY = 0
             
    DEPTH_AVERAGE_V_VELOCITY = 0
              SUSP_CLASS_1 = 1
              SEDI_CLASS_1 = 1
              ZRANGE_CLASS_1 = 1
              SUSP_CLASS_2 = 1
              SEDI_CLASS_2 = 1
              ZRANGE_CLASS_2 = 1
           EndSect  // PARAMETERS_2D
           [PARAMETERS_3D]
              Touched = 0
               CLASS_1 = 1
               U_VELOCITY = 0
               V_VELOCITY = 0
               W_VELOCITY = 0
           EndSect  // PARAMETERS_3D
           [PARTICLE_TRACK]
               Touched = 0
                CLASS_1 = 1
            EndSect  // PARTICLE_TRACK

    EndSect  // OUTPUT_2