Help for GridGen

July 4, 2003, 07:17

Hi, every one

is there any one has the experience in the application of GridGen to gerenate meshes used for the simulations for viscous flow around airfoils? My problem is, with which function or process in Gridgen, the grids adjacent to the solid wall will be of small stretching, and the first one is of the order 1E-5 or 1E-6 according to the chord length.

thanks for any reply

YANG

July 6, 2003, 23:44

Where is the customer support from the company? Is it that bad?

-Bill

July 22, 2003, 18:15

Hi YANG,

Folks make viscous grids in Gridgen all the time, including variations in length scale of 7, 8, or even 9 orders of magnitude. The software is designed for double precision floating point numbers so this is well within its capabilities.

The specific feature you'd use to obtain this level of spacing depends on the type of mesh you're generating (structured or unstructured) and the particular method. For example, if you are extruding a structured quad grid, you specific the wall spacing as the initial step size in the extrusion algorithm. If you are using one of the more traditional methods, you can specific the exact spacing of the grid points near the airfoil on the end of curves and you can also specify the spacing constraint to apply in the elliptic PDE method near the wall.

If you need more specific help, please don't hesitate to contact support@pointwise.com.

July 4, 2003, 07:17	Help for GridGen	#1
YANG Guest Posts: n/a	Hi, every one is there any one has the experience in the application of GridGen to gerenate meshes used for the simulations for viscous flow around airfoils? My problem is, with which function or process in Gridgen, the grids adjacent to the solid wall will be of small stretching, and the first one is of the order 1E-5 or 1E-6 according to the chord length. thanks for any reply YANG

July 6, 2003, 23:44	Re: Help for GridGen	#2
Bill Clinton Guest Posts: n/a	Where is the customer support from the company? Is it that bad? -Bill

July 22, 2003, 18:15	Re: Help for GridGen	#3
John Chawner Guest Posts: n/a	Hi YANG, Folks make viscous grids in Gridgen all the time, including variations in length scale of 7, 8, or even 9 orders of magnitude. The software is designed for double precision floating point numbers so this is well within its capabilities. The specific feature you'd use to obtain this level of spacing depends on the type of mesh you're generating (structured or unstructured) and the particular method. For example, if you are extruding a structured quad grid, you specific the wall spacing as the initial step size in the extrusion algorithm. If you are using one of the more traditional methods, you can specific the exact spacing of the grid points near the airfoil on the end of curves and you can also specify the spacing constraint to apply in the elliptic PDE method near the wall. If you need more specific help, please don't hesitate to contact support@pointwise.com.