GASPv4 User Tips

Execution of GASPv4

• To run GASP's graphical user interface:
  • gasp
  • gasp --gui
  • gasp -g
• To run GASP's flow solver (MPI auto launch; recommended):
  • gasp --solve -i problem.inp
  • gasp -s -i problem.inp
• To run GASP's flow solver (MPI manual launch):
  • gasp --mpi -i problem.inp --run #
• To show command line help:
  • gasp --help
  • gasp -h
• GASP Short Options:
  • -g ........ runs graphical interface
  • -s ........ runs flow solver
  • -i ........ specifies name of input deck
  • -e ........ specifies AEROSOFT_HOME directory
  • -v ........ prints GASP version
  • -h ........ prints help message
• GASP Long Options:
  • --gui ............ runs graphical interface
  • --solve .......... runs flow solver (auto)
  • --mpi ............ runs flow solver (manually)
  • --dbasemgr ....... runs database manager graphical interface
  • --replacegrid .... replaces grid (non graphical)[v4.1.1]
  • --replacesoln .... replaces solution (non graphical)[v4.1.1]
  • --version ........ prints GASP version
  • --help ........... prints help message
• --mpi Options:
  • -i .......... specifies name of input deck
  • -e .......... specifies AEROSOFT_HOME directory
  • --run # ..... specifies which run definition (1 based)[v4.1.1]
  • --elmhost ... specifies AEROSOFT_ELMHOST variable
  • --fpe ....... runs with floating point exceptions turned on
  • --help ...... prints help message for --mpi option
  • With the manual launch of gasp (--mpi), the user must add the correct MPI arguments to run the solver.
  • Only one run defintion will be executed by the solver, which is the one specified by --run argument.
  • Type gasp --help --mpi for more information
• --solve Options:
  • -i .......... specifies name of input deck
  • -e .......... specifies AEROSOFT_HOME directory
  • --elmhost ... specifies AEROSOFT_ELMHOST variable
  • --fpe ....... runs with floating point exceptions turned on
  • --help ...... prints help message for --solve option
• --replacegrid Options:
  • type gasp --help --replacegrid
• --replacesoln Options:
  • type gasp --help --replacesoln

Environment Variables

• AEROSOFT_HOME --> Sets the AeroSoft Home directory.
• AEROSOFT_NOTMP --> Forces GASP not to make a back-up of the adf file when saving.
• AEROSOFT_FPE --> Turns on floating point exceptions for both SGI and Linux machines.
• AEROSOFT_ELMHOST --> Directs the search for a license key to a specific mahcine.
• AEROSOFT_NOGLBLENDEQUATIONEXT --> When defined, the GUI will not make calls to glBlendEquationEXT. Note this OpenGL call is not supported by all XGL servers
• ELMTIMEOUT --> Sets the time out (in seconds) for the license manager. Default is 15 seconds. When the flow solver goes to check for a connection with the server, this is how long it waits before timing out.
• ELMRETRIES --> Sets the number of retries for the time out. Default is 2 retries.

Stopping GASP & Writing

• The following applies to v4.1.1 and above:
• If the file "stopgasp" exists, GASP will write the solution and stop the flow solver. The file "stopgasp" will be removed
• If the file "writegasp" exists, GASP will write the solution and then continue the flow solver. The file "writegasp" will be removed
• An easy way to create these files is using touch (ie. touch stopgasp).

MPI Info

• SGI native uses MPI array services; mpirun is used to start jobs
• SGI machines may need to set the environment variable MPI_GROUP_MAX when running in parallel.
• LAM MPI uses mpirun (aliased to mpirun.lam) to start jobs
• Compaq Alpha native uses either Compaq MPI (MPI started with dmpirun) or SC MPI (MPI started with prun)
• IBM SP native uses poe to start MPI
• Compaq SC MPI and IBM SP native MPI must use the --mpi option with GASP (not the --solve option)

General GUI Notes

• GASP searches the files ${AEROSOFT_HOME}/etc/gasprc and ~/.gasprc for default settings in the GUI.
• When post-processing, use %t for time and %n for cycle number (ie, file name extensions).
• In the run definition, use %d to specify sequential machine name.

Chemistry Database

• The database was converted from binary to XML format with the v4.2.0 release.
• To convert a Version 4 binary database to XML format, use the v4.2+ database gui (gasp --dbasemgr).
• The Version 4 binary database (.ie. db1.bin) is not compatible with Version 3.2.
• To convert a Version 3.2 database to Version 4 binary, run the Version 4 DBASEMGR (dbasemgr) and read in the database. When you save, the new database file will be in Version 4 binary format.
• The database format was updated for Version 4.1. A v4.0 database will still work with v4.1, but it is recommend to update the database using DBASEMGR. (read in database and then save)

Main Section

• In version 4, the reference length is not used to convert the grid dimensions into meters or feet. This is now done with the unit system selector. You will need to create a unit system that will convert your grid properly.
• You may also scale your grid inside the GUI using the grid transformation option inside the Zones-->Grid/Soln Mgt section.

Zones/Zonal Bouns

• The split surface command must be done before mesh sequencing.
• To create a zonal boundary manually, make a new pt2ptZB folder and drop the two surfaces in. Go to the Zonal Boun section and the Pt2PtZB tab. Set the parameters there to complete setup of the zonal boundary.

Physical Models

• Each speci name must be unique. Passing of information across zones is done by comparing the speci name.
• If you are using the Gordon/McBride option, make sure the temperature is in the valid curve fit range.
• For low subsonic flows, use Roe flux with preconditioning.
• For incompressible perfect gas flows, use the artifical compressibility flux.

Run Definition

• With a strong shock, it may be best to use a combination of local and freestream CFL. A freestream CFL will help converge the shock location, but a local CFL will converge the viscous layer faster.
• Running in parallel with Lam MPI will start processes in the order of the bhost file, and if you run more procs than in the file it will circle back onto the beginning or not run at all.

Time Accuracy

• When running a time accurate problem, the following limitations exist:
• Cannot add a motion model after starting time accurate.

Chimera

• When making Chimera overlap grids, it is best that the outer four rows of cells overlap.
• The outer two rows of an overlapping grid should be relatively close in grid size parameters (ie. cell areas and volumes) to the grid it overlaps.
The quality cutoff value should never be less than 0.1

Output Properties

• %n, and %t maby be used to change the behavior of the file name.
• %n is used for the cycle number.
• %t is used for the physical time (seconds).

License Server

• The license server requires a valid IP address (not 127.0.0.1)
• When running the license server, use full paths for the Keys directory and log file

AeroSoft, Inc. 2000 Kraft Drive, Suite 1400 Blacksburg, VA 24060 (540) 557-1900 Fax (540) 557-1919 Email questions@aerosoftinc.com