[mina00]

Hi All.
I read the Flow3D user manual and I don’t understand some of concepts of this manual and </SPAN></SPAN>I do not know how they should be set? Such as Mesh plain, Domain removing, FEA Domain removing, Mass – Momentum sources and Valve sampling volume in Baffle Segment???
Before, Maxime explain about time step very well that this were my problem.
Thanks for your guiding.

[macsim]

Hello Mina,

Mesh planes serves to detail geometry. With mesh blocks, sometimes the geometry isn’t correctly modeled, when geometry doesn’t fit exactly to mesh cells. To detail geometry, you can use mesh planes and put them where the geometry isn’t correctly modeled (often near thin objects). If you don't understand I can take print screen.

Domain removing and FEA domain removing I don’t use it. If I well understood, domain removing it’s a component type which serves to delete one part of the geometry, of the domain. For example, you have a complete geometry and can’t modify it, you can had this kind of component to delete one part of the geometry. May be somebody have better explanations for it. I don’t really understand difference with FEA domain removing.

Mass-momentum source; I will take Flow-3D definition; I think it’s well explained:

The mass-momentum source model allows the user to introduce fluid at any location and orientation into the computational domain at a specified (time-dependent) flow rate and velocity without having to model the geometry of the actual source. A mass-momentum source is represented by an array of particles of a special type in a planar surface. Users only need to define the location, shape and orientation of the source surface, and the solver will generate these particles automatically at the specified location in a pattern that follows the user-specified shape and orientation.

And the last point I don’t see any information about it, in Flow 3D software or manual. Where do you see this point (which chapter) ?

Sorry, my english isn't very good ! But if you have other questions or if my explanations aren't clear, don't hesitate.

Bye !

[mina00]

Hello macsim
So thanks.
I don’t understand mesh plane very well!!! In The example of Flow3D such as Flow over a weir or others some mesh planes are negative. And I don’t know how I determine it?
Valve & sampling volume in Baffle segment, I was wrong!!
The manual is hard for me and I don’t understand some of concepts and sentences.

[macsim]

Which version of Flow 3D do you have ? I want to find the example you are reading, it will be easier to explain it to you

[mina00]

Hi macsim
I have Flow3D 10.1.0.
so thanks.

[macsim]

Hi Mina,

And can you explain to me where can I find your example ? (clic on "Help"... ?) I don't find mesh plane explanations in flow 3D example.

Thankksss

[mina00]

Hello macsim
The example explaine in chapter three. page of 37.
How you determine mesh plain for one project?
What's mesh plain based on?

[macsim]

Good morning Mina,

I'm sorry, I don't find it. I've also V10.1 but I don't have this kind of help manual as in V10.0.2.

Now when I click on "help", flow 3D open this page (see attachment).

But I find some definitions from "my" help manual, may be it can help you.

Mesh Planes also called fixed points or grid plane locations: the first and last mesh planes in a given direction define the mesh domain. Intermediate planes may also be defined to force the mesh to align with specific geometric features or to allow non-uniform resolution.

Intermediate mesh planes are also useful as they may be used to ensure that a grid line is aligned with a baffle, an obstacle edge, or with an inlet or outlet opening. Occasionally, intermediate mesh planes are used to force geometric symmetry since there may be some round-off error when creating a mesh. An example would be specifying mesh planes aligned with the axis of a circular hole.

Keep me informed

[mina00]

Hello macsim
So thanks.
chapter 3 (Tutorial) explain the example of Flow over a weir completely.

Mass-Momentum Sources,Valves and Sampling Volumes explain in page of 229-232.

You want to show me a print screen about nesh plain??

[macsim]

Hello Mina,

So yes, maybe it will be easier if I made my own example

For example, when I create a mesh block, my geometry is totally included in the mesh block.

But sometimes, the geometry doesn’t fit exactly to the mesh cells :
Image 1

Due to that, when I run Favor method, the geometry isn’t correctly modelized :
Image 2

To correct this defect, I have to put a mesh plane near "geometry limits" to have a better geometry modelization
Image 3 & 4

In this case the modelization differences aren't very important. But sometimes, without mesh planes you can loose a lot of geometry volume. In my case (cavity filling process), I use mesh planes for this use. Maybe there are other possible usages.

I hope I've been enough clear, but doesn't hesitate if you have other questions.

[mina00]

Hi macsim
Your explanation is very good.
So thanks.
good luck