CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums

Blog Entries

Register Blogs Members List Search Today's Posts Mark Forums Read

Old

blockMesh,snappyMesh and experimental results for 2D airfoil

Posted April 1, 2013 at 04:17 by skeptik (CFD notes)

A certain Mahdi wrote me via e-mail, that my tetra-mesh and hybrid mesh was not good for simulations.

So here i show results which were obtained with C-mesh generated by blockMesh utility OF, and snappyHexMesh.

blockMesh domain

Name:  hexaMesh1.jpg
Views: 3744
Size:  76.8 KB

mesh near wall

Name:  hexaMesh2.jpg
Views: 3136
Size:  88.2 KB

snappyHexMesh domain

Name:  snappy1.jpg
Views: 2565
Size:  86.3 KB

boundary layer discretization

Name:  snappy3.jpg
Views: 3507
Size:  85.5 KB
...
Attached Images
File Type: jpg hexasSimple.jpg (44.1 KB, 1896 views)
Member
Posted in Uncategorized
Views 3956 Comments 11 skeptik is offline Edit Tags
Old

about polyDualMesh "Try something smaller than 90"

Posted March 28, 2013 at 02:06 by skeptik (CFD notes)

Quote:
Originally Posted by lillberg View Post
Try something smaller than 90 deg feature angle since it represents the maximum angle between two neighboring surface normals on a surface without corners. That is, the mesh will consider your surface shape a corner if the angel is larger than this value. I typically use something between 45 and 80 depending on the tet mesh resolution on highly curved surfaces. This might be the root of your problem. Looking at my picture the curved surface in the middle would (wrongly) be treated as a corner if
...
Member
Posted in Uncategorized
Views 743 Comments 0 skeptik is offline Edit Tags
Old

note about convergence

Posted March 26, 2013 at 05:39 by skeptik (CFD notes)

Quote:
Originally Posted by chegdan View Post
Nick,

There are some strategies that I would try to get these residuals down to something you would like.
  1. Lower your pressure relTol by an order of magnitude compared to U i.e. relTol = 0.001 for P and relTol = 0.01 for U.
  2. Without knowing the mesh you are using you may need to increase the nonorthogonal corrector by 1 or 2. if you are using a tet mesh...then there are many things you can do.
  3. Use first order schemes to start with (you will move to higher order ones
...
Member
Posted in Uncategorized
Views 526 Comments 0 skeptik is offline Edit Tags
Old

My cfd learning starts

Posted March 24, 2013 at 23:44 by vijaiaeroastro

Hello fellow cfd fans,
I am starting my deep cfd learning today. i found a material published on finite difference methods and i am going to start from a very simple fluid dynamic problem from today onwards. wish me luck!!
New Member
Posted in Uncategorized
Views 566 Comments 0 vijaiaeroastro is offline Edit Tags
Old

Forgotten post about airfoilmesh. Domain shape

Posted March 22, 2013 at 05:00 by skeptik (CFD notes)

First time i tried domain like this

Name:  quad.jpg
Views: 508
Size:  24.3 KB

And i got no good results cause pressure distribution shown problems with BC

Name:  p_freestr.jpg
Views: 498
Size:  15.1 KB

I tried to make a circular domain like in this work shown in the next figure

Name:  hybrid3.jpg
Views: 536
Size:  68.0 KB

and only with circular domain i get physically reasonable results.

other figures about mesh i used to

Name:  hybrid_refined.jpg
Views: 552
Size:  83.7 KB Name:  hybrid1.jpg
Views: 691
Size:  85.0 KB...
Member
Posted in Uncategorized
Views 1082 Comments 0 skeptik is offline Edit Tags

All times are GMT -4. The time now is 14:08.