cfreset_iter

cfreset_iter is used to reset the iteration count in a common flow (.cfl) file to zero. This may be useful when you are using an existing solution to initialize a new simulation, and would like to start the iteration count at zero. Simply type "cfreset_iter" and you'll be prompted for the .cfl file name, which should include the .cfl extension.

More exactly, cfreset_iter sets the following data in the .cfl file to zero:

• The number of the last zone completed, the number of cycles completed, and the number of Newton time levels completed (stored in the root node header)
• The maximum residual for all zones (stored in the root node)
• For each zone, the maximum residual, the number of iterations completed, and the integrated time (stored in each zone node)

Note that the original .cfl file is actually modified by cfreset_iter, not copied. If the file containing the original iteration count and residual data will be needed in the future, you'll need to manually copy it to a different file name before using cfreset_iter.

Note also that at the start of a Wind-US calculation with structured grids, the boundary condition at viscous walls is gradually changed from slip to no-slip over a specified number of iterations (the default is 50). If you're restarting a structured grid case with viscous walls after using cfreset_iter, you probably don't want this behaviour. The WALL SLIP keyword should be used in the input data (.dat) file to specify that a no-slip boundary condition is to be applied from the first iteration, as follows:

   WALL SLIP ITERATIONS 1

A terminal session illustrating the use of cfreset_iter is shown below, for a common flow file named case3.cfl. Lines in a slanted font are typed by the user.

   % cfreset_iter
   
                                ***** cfreset_iter *****
   
             Select the desired version from the following list.
   
   0) END
   1) cfreset_iter optimized version
   
   Single program automatically selected.
   
    cfreset_iter - Version 1.8 (last changed 2007/02/13 23:54:58)
    ****************************************************************************
    * Warning: This software contains technical data whose export is           *
    * restricted by the Arms Export Control Act (Title 22, U.S.C., Sec 2751,   *
    * et seq.) or Executive Order 12470. Violation of these export-control     *
    * laws is subject to severe criminal penalties. Dissemination of this      *
    * software is controlled under DoD Directive 5230.25 and AFI 61-204.       *
    ****************************************************************************
     Enter name of the common flow file.
   case3.cfl
     Working on ZONE   1
     Working on ZONE   2
     Working on ZONE   3
     All fixed!!!!!!!!!