Learning Forum

[scabo]

Hi 

 I have used a O grid mesh on a 3D  1.25 m pipe and then used multizone>uniform surface mesh method to mesh the pipe. I am trying to make the mesh coarser in the streamwise direction. After that i am specifying the number of divisons on the edges as shown in the attached picture. But it is not having any effect on the mesh as the elements number and the mesh lengths are coming same for different edge sizing numbers. What can be the issue? Is it because the pipe is long? Previously i tried with a much shorter lenght and this method worked. Can someone please suggest how can i make the mesh coarser in the streamwise direction but keep it fine in the cross-section? I have attached the picture. thanks!

[CFD_Friend]

Hi,

You can make use of sweep meshing. Mesh one end of the pipe, and then use sweep method to mesh the streamwise direction. You can specify the sweep number of divisions. This avoids the need to specify edge sizing.

[scabo]

It worked but when i am changing the sweep divisons it is changing the element size on the cross-section also, which is not very common because once i fix the element size on the c_s and change the sweep number of divisons then it should only change the element size streamwise but not on the c_s, Right?

[CFD_Friend]

Hi,

Then provide face sizing on the seed face. This should constrain the sizing of the elements.

[scabo]

In the sweep method in order to select the seed face we need to select manual source and target right? If i do that theres a bit of unstructuredness in the mesh cross-section. It is not comming perfectly smooth like O grid mesh

[scabo]

When u mention mesh one end of the pipe, how to do that? I meshed it using sweep and it meshed the whole pipe not any end..

[scabo]

Also sweep does not work with inflation layer options..

 

[CFD_Friend]

Hi,

Using Sizing option and choosing the source face. Provide a size for the element. Then insert inflation, and choose face as the geometry, and the circumference edge as the boundary. Then insert the sweep method and choose the same face as source. Provide sweep divisions. Now mesh.

This way inflation will be present.

[scabo]

Hi, thanks very much. I used a different procedure in the mean time: do a multizone for all the bodies and then supress each body, do the meshing on each with edge sizing and inflation and then unsupress and do the rest. It worked. But i will try your method as well.

thanks