FlowCart Interface

This interface creates flowCart  multi-grid file , input parameters control file and  runs the solver.

flowCart Files

• flowCart.par:   flowCart parameters file ( translator intermediate file )
• filename.cntl:  flowCart input parameters control file
• filename.R:     flowCart Reordered mesh file
• filename.mg:   flowCart mult-grid file
• forces.dat:      flowCart output forces data file
• history.dat:     flowCart convergence history file
• filename.triq:  flowCart output tri file with nodal Pressure coefficient appended.

Reorder - MultiGrid

    Reorder takes meshes form cart3D mesher and reorders them using a space-filling-curve based ordering. There are options for using either  Morton or Peano-Hilbert SFC's to reorder the mesh. In general Peano-Hilbert produces slightly better partitionings and therefore its set  up as the default.
      flowCart takes these re-ordered meshes and can partition them on-the-fly onto any number of processors.  Even on a single CPU (unpartitioned domain) its worth reordering, since reordered meshes have better locality and will execute faster on cache-based machines.

mgPrep is the mesh coarsening module which creates coarse grids from an initial input grid for flowCart's multigrid convergence accelleration. Ordering of the input meshes is preserved and is propagated to coarser meshes in the hierarchy.

flowCart Input Parameters

    flowCart solver input parameters are specified in this form.

 

    File Information:

        Mesh file is the flowCart input mesh file which could be either one of cart3D mesher output file, reordered mesh file and multi grid mesh file.
        Mesh Info file is the mesh information file written by cart3D mesher.

    Case Information:

        Mach Number
        Angle of attack ( alpha ) in degrees
        Side slip angle ( Beta ) in degrees
        Free Stream Density ( Rho_inf )
        Free Stream Sound Speed ( a_inf )

    Solver Controls - Runge-Kutta scheme:

        Number of stages in the RK scheme.
        Stage coefficient for each  stage
        Gradient Evaluation  flag for each stage:
                                                0 - Do not evaluate
                                                1 -  Evaluate

    Solver Controls - Others:

        CFL number
        Limiter Type
        Flux Function
        Cut cell boundary condition type
        Number of Multi-Grid levels
        Multi grid cycle type
        Number of pre smoothing levels in multigrid
        Number of post smoothing levels in multigrid

    Boundary Conditions:

        Specify boundary condtions for  low and high in X,Y,Z directions:
                    FARFIELD
                    SYMMETRY
                    INFLOW
                    OUTFLOW

    Convergence History:

        Specify convergence hoistory information update controls:
            Force information update cycle
            History file update cycle
        Convergence criteria.

    Partition Information:

     Specify Number of SubDomains to partition into and the Type of partitioning:
                                1 = SpaceFillingCurve

flowCart Input

    Write the flowCart parameters to the selected flowCart input control file.

Run flowCart

    Select the flowCart input control file.
    Slect the maximum number of cycles.

    Restart computation:  This is to restart the computation from the last run. flowCart creates check_$cycles file for every run.  Create a soft link to the fowCart output check file  like below and turn on Restart  button and run solver.
                   ln -s Restart.file check_0010
 

Running  in Parallel

    flowCart parallelization is done using the OpenMP standard. Thus, although it uses explicit message passing, it is formally a shared memory model. So, it can run only on shared memory parallel machines.
    To run in parallel set  MP_SET_NUMTHREADS environment variable to the desired number of processors.  For ex, to run flowCart in a 10 CPU machine:
in csh,
     setenv   MP_SET_NUMTHREADS 10

Post Processing

    ICEM_VISUAL3

      flowCart output tri file (filename.triq) with nodal pressure data can be converted to domain file by running c3dtri2df translator like,
        $ICEM_ACN/icemcfd/output-interfaces/c3dtri2df -i  filename.triq -o filename.dom -triq

    This domain file can be imported in to  ICEM-Visual3 post-processor as surface domain file.

    clic Post-processor

        clic is a Component based force and moment module developed as a post-processor and data-extractor  for Cart3D. Using clic, you can extract Cp cuts on any component or group of components in your configuration, you can compute LDM (lift, drag, moment) for components, component groups or configurations, and extract the usual bevy of point-moments, line-moments ("hinge, moments") etc..

    sixDOF utility

        This computes the motion of a general 6-DOF model for an unconstrained rigid body under the influence of aerodynamic forces, gravity, and external applied loads.

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