Onera M6 wing using grid from cfl3d

Help
Praveen. C
2007-09-24
2013-04-29
  • Praveen. C

    Praveen. C - 2007-09-24

    Hello,
    I am trying to run the Onera M6 wing case using the grid from cfl3d test cases. But I am getting negative pressures. Any suggestions on how to oversome this problem. My input file is below.

    Thanks
    praveen

    'GRID FORMATTED'  0
    'GRID'     1
              'grid.fmt'
    'RESTART OUT'    1
                    'm6.rst1'
    'PLOT3D'   0
              'FORMATTED'
              'm6'
    'MACH'       0.84
    'RE'         21.66E6
    'ALPHA'      3.06
    'BETA'       0.0
    'KAPPA'      0.3333333333E0
    'LIMIT'      3
    'K OMEGA'    0
    'MULTIGRID LEVELS' 3
    'MESH SEQUENCE'    2
         1000
         1000
    'NITS'       10000
    'CFL'        0.05
    'CFLFNL'     5.0
    'ITDFNL'     1000
    'ITUPDT'     5

    'BLOCK' 1 
       'DIMENSIONS' 1
          289  65  49
       'FLUX' 1
          'ROE' 1
       'VISCOUS' 3
           1  2  3
       'BC' 7
          'BC'      1   1   1      1  65  49  'FARFIELD'
          'BC'    289   1   1    289  65  49  'FARFIELD'
          'BC'      1   1   1     33   1  49  'EXTRAPOLATE'
          'BC'     33   1   1    257   1  49  'WALL'
          'BC'      1  65   1    289  65  49  'FARFIELD'
          'BC'      1   1   1    289  65   1  'SYMMETRY XZ'
          'BC'      1   1  49    145  65  49  'EXTRAPOLATE'
    'END BLOCK' 1

    'CUT' 2

    'CUT1'   1     1   1   1    33   1  49
    'CUT1'   1   289   1   1   257   1  49  1 2 3

    'CUT2'   1     1   1  49   145  65  49
    'CUT2'   1   289   1  49   145  65  49  1 2 3

    'END' 0

     
    • Praveen. C

      Praveen. C - 2007-09-26

      Should I make the changes discussed in this message ?

      http://sourceforge.net/forum/message.php?msg_id=2866317

      i.e. the farfield BC for turbulence quantities and omega WALL BC.

       
    • Joseph H. Morrison

      When are you getting the negative pressure and where in the flowfield is it?

      The boundary conditions for the turbulence do need to be fixed; they could easily be affecting this solution. Also, I typically run less iterations on the coarse grids and increase the CFL quicker. The value of CFL of 5.0 may be too high for this case. I would recommend reducing the maximum CFL to 2 or 3 to see what happens. First order advection on the turbulence equations would also stabilize the solution.

      I will have to try to run this case to see what is happening.

      Joe

       

Log in to post a comment.

Get latest updates about Open Source Projects, Conferences and News.

Sign up for the SourceForge newsletter:

JavaScript is required for this form.





No, thanks