[krndv]

1. i am getting good mesh after castellated mesh but loses it later. Is it necessary to do snapping? can I make it false and use castellated mesh for simulation?


2. In 2d axisymmetric simulation it calculates Ux and Uz not Uy. Geometry is in x-y plane , rotated along y-axis

[krndv]

Originally Posted by piu58

The resulting angel may be configured in system.rotataionDict->wedgeAngle

The z coordinate will be ignored.

Hello,

In a 2D-Axisymmetric problem, the residuals are showing for Uz means its calculating in third direction.
Wedge patch given to front and back.
Rotation tried with 5 and 2 degree, same results for both.
Checkmesh is showing Ok.

[siemienk]

Hi Tobi,



how to find your tutorial about 2d axi-symmetric cases?


I am currently doing a simulation using wedge boundary condition.
I have specified inlet, outlet, wedge at the front and back, and wall at the top.

I haven't however put anything in the boundaries or anywhere else about the axisymmetric axis.

1) Is that correct? Or should the axis be specified somewhere in the case set up? ]
2) Simulation runs okay and the results seem to be ok, but I do get warning about from and back patch being not planar. Do you think that is a problem? Nothing crushes, it just a warning.

I have them not planar, because earlier I got an error saying that the wedge should be same number of degrees away from the rotation axis.



I will be grateful for your help.



Karolina

[chrisyang]

Originally Posted by Tobi

Hi all,

I just want to complete the not 100% correct things here and want to sum up:

• The angle should be 5° (as Wouter said for 2D); checkMesh will tell you the angle
• The angle can be adjusted in the extrudePatchDict (I am talking always about the latest Foundation FOAM version, maybe the extend version is different and Uwe refers to this version)
• The z-direction will not be neglected in a way one expect while using the word neglected; only the treatment of the faces at the patches is different. FOAM uses FVM, so we need 3D volume elements. The empty or wedge patches are then treat the 3D case in a special manner to enable 2D and 1D analyzes (maybe you can say ignoring but I guess this expression is not the best choice; people might be confused why we even use a 3D mesh for 2D simulations); even in 1D simulations we need a 3D mesh based on the FVM

Hello Tobias,

Thanks for your clarification. Regarding to last statement, can I interpret that openfoam only support 3D cartesian coordinates simulation, but it could down to 2D analysis by specifying empty/wedge BCs and single layer of cells in the direction out-of-page? So, if I have a multiphase flow problem in 2D axis-symmetric wedge domain, it will still calculate surface tension in 3D?

Best,
Chris

[atelcikti1]

Hi guys,

I didn't want to make new thread about the subject.

I am trying to create a mesh in pointwise for openfoam. I generate 2D axisymmetric (I hope) structured mesh (choosing 3D option and extruding around x axis by 5 deg and 1 cell). Then I have three questions;

1) which axis must be rotation axis? is there a restriction in openfoam?
2) if there is no restriction, how can i explain to OF my rotation axis? is there a specific input file and option to define it?
3) I give the face boundary conditions correctly, but i couldn't figure out volume conditions. which volume condition do i have to choose in pointwise (ie. volumetocell, volumetoface etc. there are bunch of options)?

[Tobi]

1. As far as I know not but I always use the x, y, or z axis
2. Boundry condition -> wedge
3. no idea about what you are talking