[mk091088]

Hello everyone,
I would appreciate if you help me. I am trying to mesh two surfaces, one is a core (smaller circle) and one is bigger circle. However, I want to mesh both faces separately, that is, when I want to mesh the bigger face, the smaller circle is also meshed. I am trying to split both faces but it does not work. How can I mesh both smaller circle area and the area between smaller circle and bigger circle (annulus) separately?
I attached you the photo for you.

[ghost82]

You need to split big circle with small circle. then you should also split the annular region with other 4 edges to make it fully mappable.

[alejandro_1980]

Originally Posted by mk091088

Hello everyone,
I would appreciate if you help me. I am trying to mesh two surfaces, one is a core (smaller circle) and one is bigger circle. However, I want to mesh both faces separately, that is, when I want to mesh the bigger face, the smaller circle is also meshed. I am trying to split both faces but it does not work. How can I mesh both smaller circle area and the area between smaller circle and bigger circle (annulus) separately?
I attached you the photo for you.

You need after created both surfaces, in boolean operations substract the small circle of the larger circle with the retain check list on (red square).

Good Luck¡¡

[-mAx-]

How did you create the small core: is it a circle (edge) or a circle (surface)?

Just to use the good words, (and as Daniele mentionned), you need to split the big disk (surface) with the small circle (edge). It will delete the big surface, and create the annular surface and also the core as surfaces.
So if you already had a core as surface, you will have 2 core surfaces (you will have to delete the one which isn't connected)

The procedure from alejandro is also good if you previously have the 2 surfaces (big and small disk)

[mk091088]

Thank you for your response. I will explain you my case. The Idea is to use multiphase flow model using ,lets say fluid 1 and fluid 2. I want to have fluid one comes to the smaller cylinder while fluid 2 inject from annular (the distance between small and bigger cylinder). Since I could not to separate faces, I tried to define another cylinder as injector for fluid 1 and annular as fluid 2.
Here is the procedure that I have done:
• I created a cylinder with height of 500mm and radius 50mm in positive x direction.
• I created a cylinder with height of 300mm and radius 30mm in negative x direction.
• But I could not split input flow phase face (fluid 1) from its respective volume, also the same for annular for fluid 2.

I do not know what the problem is?
I have Another question : when I export my straight pipe as .mesh file from Gambit to Ansys fluent, instead of inflow and outflow faces, interior face is created in boundary condition of setup solution. I guess this is due to again attachment of faces to their volume? right? again I attached the photo.

[-mAx-]

first question:
how many volume do you have in gambit?
Ïf you will use multiphase, you need at least 2 volumes: one for the first cylinder and the rest.
Regarding your last question: did you set the boundary conditions?

[mk091088]

Thank you Max for your concern. Actually I solved the problem. Regarding to your explanation about two volume, should I mesh two volume separately?or I can use one mesh for both volumes? both cylinders have different diameters. If I have to mesh volumes what about the faces?

[-mAx-]

you will have to mesh them separately, because you will define 2 different fluid domains for your multiphasis.
You will then inialize thre vof variable differently on both fluid domains

[mk091088]

I meshed two cylinders separately as you mentioned. Total number of 53856 meshes are obtained with the following quality:

Minimum Orthogonal Quality = 7.84460e-01
Maximum Ortho Skew = 2.15540e-01
Maximum Aspect Ratio = 9.38615e+00

The problem is that I do not have any sense in these parameters? Are they good?

[-mAx-]

https://www.sharcnet.ca/Software/Gam....htm#gc_exmesh
select range
select all you type of element (tetra / wedge /hexa)
set lower with 0.9 (if you have tetra element) or 0.8 if full hexa
check how many cells do you have between lower and upper limit
If 0 element, then your mesh should be ok

On the other hand, you may import your mesh in fluent, and then check mesh