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TURBULENCE MODEL NUMERICAL ANALYSIS

Grids - NACA 0012 Airfoil Case

NOTE: The original posted grids were based on the scaled NACA 0012 airfoil shape with a small typo in one of the coefficients. Although at this time the typo is believed to make insignificant difference in the results, all grids have been re-generated with the corrected airfoil shape as of 6/23/2014.

Three families of grids are provided. All have a farfield extent of approximately 500 c. Each family's finest grid is 7169 x 2049, with minimum spacing at the wall of 1 x 10^-7 and average stretching rate normal to the wall of about 1.02 for the points near the wall. The leading edge spacing along the airfoil in all families is the same: 0.0000125 c. The difference between the families is in their trailing edge streamwise spacing:

• Family I: T.E. spacing = 0.000125 c
• Family II: T.E. spacing = 0.0000125 c (10 x finer than Family I)
• Family III: T.E. spacing = 0.0000375 c (3.3333 x finer than Family I, and 3 x coarser than Family II)

A series of 7 nested 2-D grids are provided for Families I and II, whereas in the interest of space only the finest grid is provided for Family III. Each coarser grid is exactly every-other-point of the next finer grid, ranging from the finest 7169 x 2049 to the coarsest 113 x 33 grid. (Please contact the page curator if you are unable to extract coarser levels for Family III.) The topology is a so-called "C-grid," with the grid wrapping around the airfoil from downstream farfield, around the lower surface to the upper, then back to the downstream farfield again; the grid connects to itself in a 1-to-1 fashion in the wake. There are 4097 points on the airfoil surface on the finest grid, with 1537 points along the wake from the airfoil trailing edge to the outflow boundary. The figures below show views of the 449 x 129 grid for each family.

Note: be sure to use double precision when reading the grids!

FAMILY I

FAMILY I STRUCTURED VERSIONS OF GRIDS

PLOT3D Files

The structured PLOT3D grids are given in two different ways, as 2-D grids (x-y plane) or as 3-D grids (two identical x-z planes, separated by a distance y=1, giving one spanwise cell for all grid levels). You may use whichever is more convenient for your particular application.

Format for the structured 2D grids is PLOT3D-type, formatted, MG, 2D (nbl=1) - note that you must use double precision when reading! :

      read(2,*) nbl
      read(2,*) (idim(n),jdim(n),n=1,nbl)
      do n=1,nbl
        read(2,*) ((x(i,j,n),i=1,idim(n)),j=1,jdim(n)),
     +            ((y(i,j,n),i=1,idim(n)),j=1,jdim(n))
      enddo

Download the 2-D version of the FAMILY I grids in PLOT3D format (gzipped) here:

• FAMILY I (2-D) 7169 x 2049 (4097 points on airfoil surface) (242 MB)
• FAMILY I (2-D) 3585 x 1025 (2049 points on airfoil surface) (58 MB)
• FAMILY I (2-D) 1793 x 513 (1025 points on airfoil surface) (13 MB)
• FAMILY I (2-D) 897 x 257 (513 points on airfoil surface) (< 10 MB)
• FAMILY I (2-D) 449 x 129 (257 points on airfoil surface) (< 10 MB)
• FAMILY I (2-D) 225 x 65 (129 points on airfoil surface) (< 10 MB)
• FAMILY I (2-D) 113 x 33 (65 points on airfoil surface) (< 10 MB)

Format for the structured 3D grid is PLOT3D-type, formatted, MG, 3D (nbl=1, and idim in this case is 2) - note that you must use double precision when reading! :

      read(2,*) nbl
      read(2,*) (idim(n),jdim(n),kdim(n),n=1,nbl)
      do n=1,nbl
        read(2,*) (((x(i,j,k,n),i=1,idim(n)),j=1,jdim(n)),k=1,kdim(n)),
     +            (((y(i,j,k,n),i=1,idim(n)),j=1,jdim(n)),k=1,kdim(n)),
     +            (((z(i,j,k,n),i=1,idim(n)),j=1,jdim(n)),k=1,kdim(n))
      enddo

Download the 3-D version of the FAMILY I grids in PLOT3D format (gzipped) here:

• FAMILY I (3-D) 2 x 7169 x 2049 (4097 points on airfoil surface) (322 MB)
• FAMILY I (3-D) 2 x 3585 x 1025 (2049 points on airfoil surface) (79 MB)
• FAMILY I (3-D) 2 x 1793 x 513 (1025 points on airfoil surface) (19 MB)
• FAMILY I (3-D) 2 x 897 x 257 (513 points on airfoil surface) (< 10 MB)
• FAMILY I (3-D) 2 x 449 x 129 (257 points on airfoil surface) (< 10 MB)
• FAMILY I (3-D) 2 x 225 x 65 (129 points on airfoil surface) (< 10 MB)
• FAMILY I (3-D) 2 x 113 x 33 (65 points on airfoil surface) (< 10 MB)

If desired, example Neutral Map Files associated with 3-D version of the grids are given here (these files specify grid indices associated with each boundary condition - see The Neutral Map File):

• FAMILY I Neutral Map File for (3-D) 2 x 7169 x 2049
• FAMILY I Neutral Map File for (3-D) 2 x 3585 x 1025
• FAMILY I Neutral Map File for (3-D) 2 x 1793 x 513
• FAMILY I Neutral Map File for (3-D) 2 x 897 x 257
• FAMILY I Neutral Map File for (3-D) 2 x 449 x 129
• FAMILY I Neutral Map File for (3-D) 2 x 225 x 65
• FAMILY I Neutral Map File for (3-D) 2 x 113 x 33

FAMILY I UNSTRUCTURED VERSIONS OF GRIDS

CGNS Files

The unstructured versions of the same grids are all given as CGNS files. Note that the BCs written inside the CGNS files are for guidance only, and may not reflect the appropriate BCs needed for your application. To read/write CGNS files, (free) software may be necessary if your pre/post-processing tools do not already handle it. See: CGNS Website for details.

The unstructured grids are all given as 3-D grids (two identical x-z planes, separated by a distance y=1, giving one spanwise cell for all grid levels). They are given as hexahedra (quadrilaterals in the x-z plane). Note that duplicate gridpoints in the C-mesh wakes are removed when writing the structured grids as unstructured.

Download the unstructured FAMILY I CGNS grids (gzipped) as 3-D hexahedra (quadrilaterals in x-z plane) here:

• FAMILY I (3-D) unstructured quad version of 2 x 7169 x 2049 (2 x 4097 points on airfoil surface) (643 MB)
• FAMILY I (3-D) unstructured quad version of 2 x 3585 x 1025 (2 x 2049 points on airfoil surface) (171 MB)
• FAMILY I (3-D) unstructured quad version of 2 x 1793 x 513 (2 x 1025 points on airfoil surface) (43 MB)
• FAMILY I (3-D) unstructured quad version of 2 x 897 x 257 (2 x 513 points on airfoil surface) (11 MB)
• FAMILY I (3-D) unstructured quad version of 2 x 449 x 129 (2 x 257 points on airfoil surface) (< 10 MB)
• FAMILY I (3-D) unstructured quad version of 2 x 225 x 65 (2 x 129 points on airfoil surface) (< 10 MB)
• FAMILY I (3-D) unstructured quad version of 2 x 113 x 33 (2 x 65 points on airfoil surface) (< 10 MB)

FAMILY II

FAMILY II STRUCTURED VERSIONS OF GRIDS

PLOT3D Files

The structured PLOT3D grids are given in two different ways, as 2-D grids (x-y plane) or as 3-D grids (two identical x-z planes, separated by a distance y=1, giving one spanwise cell for all grid levels). You may use whichever is more convenient for your particular application.

Format for the structured 2D grids is PLOT3D-type, formatted, MG, 2D (nbl=1) - note that you must use double precision when reading! :

      read(2,*) nbl
      read(2,*) (idim(n),jdim(n),n=1,nbl)
      do n=1,nbl
        read(2,*) ((x(i,j,n),i=1,idim(n)),j=1,jdim(n)),
     +            ((y(i,j,n),i=1,idim(n)),j=1,jdim(n))
      enddo

Download the 2-D version of the FAMILY II grids in PLOT3D format (gzipped) here:

• FAMILY II (2-D) 7169 x 2049 (4097 points on airfoil surface) (242 MB)
• FAMILY II (2-D) 3585 x 1025 (2049 points on airfoil surface) (58 MB)
• FAMILY II (2-D) 1793 x 513 (1025 points on airfoil surface) (13 MB)
• FAMILY II (2-D) 897 x 257 (513 points on airfoil surface) (< 10 MB)
• FAMILY II (2-D) 449 x 129 (257 points on airfoil surface) (< 10 MB)
• FAMILY II (2-D) 225 x 65 (129 points on airfoil surface) (< 10 MB)
• FAMILY II (2-D) 113 x 33 (65 points on airfoil surface) (< 10 MB)

Format for the structured 3D grid is PLOT3D-type, formatted, MG, 3D (nbl=1, and idim in this case is 2) - note that you must use double precision when reading! :

      read(2,*) nbl
      read(2,*) (idim(n),jdim(n),kdim(n),n=1,nbl)
      do n=1,nbl
        read(2,*) (((x(i,j,k,n),i=1,idim(n)),j=1,jdim(n)),k=1,kdim(n)),
     +            (((y(i,j,k,n),i=1,idim(n)),j=1,jdim(n)),k=1,kdim(n)),
     +            (((z(i,j,k,n),i=1,idim(n)),j=1,jdim(n)),k=1,kdim(n))
      enddo

Download the 3-D version of the FAMILY II grids in PLOT3D format (gzipped) here:

• FAMILY II (3-D) 2 x 7169 x 2049 (4097 points on airfoil surface) (321 MB)
• FAMILY II (3-D) 2 x 3585 x 1025 (2049 points on airfoil surface) (79 MB)
• FAMILY II (3-D) 2 x 1793 x 513 (1025 points on airfoil surface) (19 MB)
• FAMILY II (3-D) 2 x 897 x 257 (513 points on airfoil surface) (< 10 MB)
• FAMILY II (3-D) 2 x 449 x 129 (257 points on airfoil surface) (< 10 MB)
• FAMILY II (3-D) 2 x 225 x 65 (129 points on airfoil surface) (< 10 MB)
• FAMILY II (3-D) 2 x 113 x 33 (65 points on airfoil surface) (< 10 MB)

If desired, example Neutral Map Files associated with 3-D version of the grids are given here (these files specify grid indices associated with each boundary condition - see The Neutral Map File):

• FAMILY II Neutral Map File for (3-D) 2 x 7169 x 2049
• FAMILY II Neutral Map File for (3-D) 2 x 3585 x 1025
• FAMILY II Neutral Map File for (3-D) 2 x 1793 x 513
• FAMILY II Neutral Map File for (3-D) 2 x 897 x 257
• FAMILY II Neutral Map File for (3-D) 2 x 449 x 129
• FAMILY II Neutral Map File for (3-D) 2 x 225 x 65
• FAMILY II Neutral Map File for (3-D) 2 x 113 x 33

FAMILY II UNSTRUCTURED VERSIONS OF GRIDS

CGNS Files

The unstructured versions of the same grids are all given as CGNS files. Note that the BCs written inside the CGNS files are for guidance only, and may not reflect the appropriate BCs needed for your application. To read/write CGNS files, (free) software may be necessary if your pre/post-processing tools do not already handle it. See: CGNS Website for details.

The unstructured grids are all given as 3-D grids (two identical x-z planes, separated by a distance y=1, giving one spanwise cell for all grid levels). They are given as hexahedra (quadrilaterals in the x-z plane). Note that duplicate gridpoints in the C-mesh wakes are removed when writing the structured grids as unstructured.

Download the unstructured FAMILY II CGNS grids (gzipped) as 3-D hexahedra (quadrilaterals in x-z plane) here:

• FAMILY II (3-D) unstructured quad version of 2 x 7169 x 2049 (2 x 4097 points on airfoil surface) (648 MB)
• FAMILY II (3-D) unstructured quad version of 2 x 3585 x 1025 (2 x 2049 points on airfoil surface) (172 MB)
• FAMILY II (3-D) unstructured quad version of 2 x 1793 x 513 (2 x 1025 points on airfoil surface) (43 MB)
• FAMILY II (3-D) unstructured quad version of 2 x 897 x 257 (2 x 513 points on airfoil surface) (11 MB)
• FAMILY II (3-D) unstructured quad version of 2 x 449 x 129 (2 x 257 points on airfoil surface) (< 10 MB)
• FAMILY II (3-D) unstructured quad version of 2 x 225 x 65 (2 x 129 points on airfoil surface) (< 10 MB)
• FAMILY II (3-D) unstructured quad version of 2 x 113 x 33 (2 x 65 points on airfoil surface) (< 10 MB)

FAMILY III

FAMILY III STRUCTURED VERSIONS OF GRIDS

PLOT3D Files

In order to save space, the structured PLOT3D grid for this family is only given for the finest level as a 2-D grid (x-y plane). Please contact the page curator if you are unable to extract coarser levels (which are simply every other grid point in each coordinate direction for each successively-coarser level), or if you require an unstructured CGNS version of a Family III grid. Format for the structured 2D grid is PLOT3D-type, formatted, MG, 2D (nbl=1) - note that you must use double precision when reading! :

      read(2,*) nbl
      read(2,*) (idim(n),jdim(n),n=1,nbl)
      do n=1,nbl
        read(2,*) ((x(i,j,n),i=1,idim(n)),j=1,jdim(n)),
     +            ((y(i,j,n),i=1,idim(n)),j=1,jdim(n))
      enddo

Download the 2-D version of the finest FAMILY III grid in PLOT3D format (gzipped) here:

• FAMILY III (2-D) 7169 x 2049 (4097 points on airfoil surface) (242 MB)

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Responsible NASA Official: Ethan Vogel
Page Curator: Clark Pederson
Last Updated: 11/26/2019