Wind 4.0 --> Wind 5.0 Changes

The following list summarizes the principal changes made between Wind Versions 4.0 and 5.0. The number in parentheses following the description (e.g., 5.16) is the specific version in which the change was introduced.

Wind code

The following changes have been made to the Wind code.

• The RHS keyword has been restructured, and some new combinations of differencing scheme and procedure are now available. In particular, the van Leer scheme can now use the higher order coupling methods which were previously limited to the Roe scheme only. The following table lists the various combinations of RHS keyword options available using the old and new syntax. Following the usual conventions for displaying keyword syntax, optional keyword parameters are inside square brackets.
  
  

  	Old Syntax		New Syntax
  	CENTRAL SECOND		CENTRAL
  	COAKLEY FIRST		COAKLEY FIRST
  	COAKLEY SECOND		COAKLEY [SECOND]
  	COAKLEY THIRD		COAKLEY THIRD
  	ROE FIRST		ROE FIRST [UPWIND]
  	PHYSICAL FIRST		ROE FIRST PHYSICAL
  	PHYSICAL SECOND		ROE [SECOND [PHYSICAL]]
  	ROE CENTRAL		ROE SECOND CENTRAL
  	ROE MIXED		ROE SECOND UPWINDBIASED
  	ROE SECOND		ROE SECOND UPWIND
  	ROE THIRD		ROE THIRD [UPWINDBIASED]
  	ROE THIRDU		ROE THIRD UPWIND
  	ROE FOURTHU		ROE FOURTH [UPWINDBIASED]
  	ROE FOURTHC		ROE FOURTH CENTRAL
  	ROE FIFTH		ROE FIFTH [UPWINDBIASED]
  	VAN LEER FIRST		VAN LEER FIRST [UPWIND]
  	VAN LEER CENTRAL		VAN LEER SECOND CENTRAL
  	VAN LEER MIXED		VAN LEER SECOND UPWINDBIASED
  	VAN LEER SECOND		VAN LEER SECOND UPWIND
  	VAN LEER THIRD		VAN LEER THIRD [UPWINDBIASED]
  	VAN LEER THIRDU		VAN LEER THIRD UPWIND
  	VAN LEER FOURTHU		VAN LEER FOURTH [UPWINDBIASED]
  	VAN LEER FOURTHC		VAN LEER FOURTH CENTRAL
  	VAN LEER FIFTH		VAN LEER FIFTH [UPWINDBIASED]

  
  With two exceptions, the syntax used in Wind 4.0 will still work, but is no longer recommended or documented. The exceptions are ROE SECOND and VAN LEER SECOND. In Wind 4.0, these give second-order Roe and Van Leer upwind, respectively. They now give second-order Roe and Van Leer upwind-biased, with modifications for stretched grids. (5.16)
  
  
• The HLLE explicit operator is now available as one of the choices with the RHS keyword. (5.16)
  
  With the HLLE scheme, the HLLE keyword may be used to control the behavior of the anti-diffusion term. (5.104)
  
  
• The restriction on number of grid points required for grid sequencing has been relaxed. (5.18)
  
  
• A HOLD keyword has been added, allowing the user to specify whether total conditions or characteristics should be held at freestream boundaries with inflow. The default for ideal gases is to hold total conditions, which is different from earlier versions. (5.30)
  
  In addition, the default option for ideal gases at arbitrary inflow boundaries is now HOLD_TOTALS. (5.82)
  
  
• The time step is now recomputed at the start of each iteration, unless Newton time stepping is being used, in which case it is computed at the beginning of each Newton time level. The previous behavior, in which the time step is recomputed at the beginning of every cycle (even with Newton time stepping) may be obtained using TEST option 106. (5.45)
  
  
• An underflow limiter has been added to the algorithm used with Newton iteration to compute the new temperature at boundaries where total conditions are being held fixed. (5.50)
  
  
• The time history tracking capability has been improved.
  
  
  • Time history data may now be written into the .cth file when running in parallel mode. The TEST 125 option, formerly used to write time history data into the .lis file in parallel mode, has therefore been eliminated.
  • Many additional variables may now be tracked.
  • Restart cases will now append to an existing .cth file, unless changes have been made to the HISTORY keyword input parameters or to the reference conditions.
  • Because of changes in the .cth file format, the new thplt utility must be used when post-processing a new .cth file.
  
  The improved capability required some changes to the shell scripts used to run the Wind code. The modified scripts are wind.sh, wind_input.sh, wind_jobfile.sh, and wind_miscfns.sh, and the new versions were uploaded to IVMS on May 30, 2001. If you're currently using older versions of these scripts, updated versions must be installed in order to use the improved time history tracking. For someone with user-level access to IVMS, this can be done by downloading all the scripts and copying these four into your CFDROOT/bin directory, or by downloading and installing the current Wind application distribution. (5.52)
  
  
• Newton iteration now works for parallel runs with assignment mode shared and i/o indirect. (5.59, 5.60)
  
  
• A relaxation factor may now be used with the IMPLICIT JACOBI and IMPLICIT GAUSS keywords. (5.64)
  
  
• A problem with the use of the IJK_RANGE keyword in the ARBITRARY INFLOW keyword block, for flows with reacting or frozen chemistry, has been fixed. (5.66)
  
  
• In the .lis file, headers are now printed only when residuals are output. (5.74)
  
  
• A DIRECTION keyword has been added to the ARBITRARY INFLOW keyword block, allowing the user to easily specify that the incoming flow is normal to the boundary face, or along the grid lines intersecting the boundary face. This replaces TEST option 176, which has therefore been removed. (5.80)
  
  
• A BLOW SURFACE capability has been added to the BLOW keyword, allowing the blowing velocity to be computed, or set to zero, on a point-by-point basis, based on the specified plenum total pressure and the local flowfield static pressure. In addition, the BLOW VALVE capability has been fixed. (5.84)
  
  
• The memory allocation procedure for the flow solution phase has been restructured. (5.87)
  
  
• The DOWNSTREAM PRESSURE keyword now allows specification of either zeroth- or first-order extrapolation, and a relaxation option was added for spatially varying downstream pressures.
  
  The MASS FLOW keyword also now allows specification of the extrapolation order, and an option was added to modify the mass flow directly instead of iterating the downstream pressure. (5.97)
  
  
• Bleed boundaries are now treated as no-slip walls for the solution of the turbulence modeling equations, as well for the Navier-Stokes equations. The previous behavior, treating bleed boundaries as slip walls when solving the turbulence model equations, may be obtained using TEST option 67. (5.101)
  
  
• Several fixes have been made involving the use of CGNS files in Wind. (5.25, 5.83, 5.105, 5.137, 5.140)
  
  
• Options to use the Koren and van Albada limiters have been added to the TVD keyword. (5.106)
  
  
• The time step calculation procedure from the OVERFLOW code has been added as an option with the CFL# keyword. (5.108)
  
  
• An alternative implementation of the Roe scheme, from the OVERFLOW code, has been added as an option with the RHS keyword. (5.109)
  
  
• The ARC3D 3-factor diagonal scheme, as implemented in OVERFLOW, has been added as an option with the IMPLICIT keyword. (5.110)
  
  
• A VORTEX GENERATOR keyword has been added, for modeling the effects of vortex generator arrays on the flowfield. (5.112)
  
  
• A TDA_INVALID keyword has been added, allowing the user to reset boundary data in the .tda file. (5.122)
  
  
• Various bugs in the singular axis and pinwheel boundary conditions have been fixed. The algorithm was also modified slightly to always average the pressure and not the total energy (in addition to the density, and momentum or velocity components). (5.127)
  
  
• The algorithm used with the SMOOTHING keyword has been fixed, and the differencing techniques now match what was in the old NPARC code, which seems to work better near boundaries. (5.128)
  
  
• Various tweaks have been made to get Liu-Vinokur chemistry working properly, although there is apparently still a problem when the ARBITRARY INFLOW keyword is used with Liu-Vinokur chemistry. (5.134)

Makefiles

The following changes have been made to the Makefiles.

• Added and/or modified makefiles for IBM RS6K and Compaq alpha systems. (2.0.42)

Scripts

The following changes have been made to the scripts.

• Modifications to allow use under Cygwin on a Windows system (2.0.42)
  
  
• Added support for Compaq alpha systems (2.0.44)

Utilities

The following changes have been made to the utilities.

• Added support to CFPOST for Compaq alpha systems
  
  
• Added new thplt utility for post-processing the new time history files
  
  
• The download, build, and installation process for the utilities has been improved