Setting Up Inlet and Outlet Boundary Conditions in Fluent Meshing

Setting Up Inlet and Outlet Boundary Conditions in Fluent Meshing Hello everyone, this is Mohsen Seraj from the Ozen Engineering team.

Today, I want to show you how to specify inlet, outlet, or other types of boundary conditions when you are doing this in Ansys Fluent Meshing, not here as the usual way that you assign name selection to the inlets or outlets for safety simulation.

Let's create an enclosure for this body cylinder and accept the 25% and say yes. Yes, okay, so this is the enclosure as you can see, and this is the solid part.

Let's go for the sharing topology, and here, if it is an Ansys product, we can assign a name selection to assign, for example, here to this face, "inlet" within the name, and then select the name of the boundary condition.

These names will be moved to the Ansys Fluent machine, and then to the Ansys Fluent machine. In this way, we can assign the boundary condition. This is the usual way that you can work on that.

But if you have a very large model, as you can see, I have many solid parts, as you can see, that may be hundreds of parts, and so we have many interfaces between solid parts and also the volume domain that I created here.

As you can see, that I used the volume extraction here to create this volume domain. If, for such a large model, that I have thousands of faces and edges to be shared among all these solid parts and fluid domains, sharing topology would take a long time.

Even in one case, for a very large model, it could be a matter of days, only for sharing topology.

When we want to do sharing topology at once, here, for everything together, for solid parts and fluid domain together, there is another workflow that we basically remove the volume or the fluid domain, and we will do the sharing topology only between solid parts, and then send out this model, after sharing topology between solid parts, to Ansys Fluent for meshing.

And over there, we create the fluid domain and perform the meshing. So, in this way, when I have only solid parts here, I don't have here the way, I cannot define inlet-outlet boundary conditions using name selection in Ansys Discovery.

For such applications, I have a video to illustrate and demonstrate the workflow that I talked about.

It is another video; I will put the address link to that YouTube video in the description of this video, that you can find out how to deal with such large CFD simulations when you want to share topology and meshing and really reduce the time required for that.

So, back to the topic for this video, if we go back to the small sample model that we have, so either we have a large model that I already explained to you, that there is no way to define phases for inlets or outlets, or you can use the following conditions, because we don't have the fluid domain over there, or suppose that here, you forget.

You forget to define the Inlet and Outlet name selections. So, now I want to show you how to do this in Ansys Fluent Meshing. I just have one wall name selection, which is for solid parts.

Let's send this to Ansys Fluent Meshing, so I don't have any inlet-outlet boundary conditions so far defined in Ansys Discovery. Send out this to Ansys Fluent Meshing for meshing. Thank you for watching! This is the model that imported here.

I don't need, for now, any local sizes, and I go with the given values for the maximum minimum for surface meshing.

I have the surface meshing here, for geometry, I just go by solid region, no capping, and I don't need the sharing topology or multi-zone, just go to describe geometry, I need to add one fluid zone as you can see it, so I choose it as a fluid, so this is solid walls, this is what I use the name for that, the name selection in Ansys Discovery, and this, before updating and performing the regions here, I can see that what I have here for the faces, you can see that this is the enclosure that I have, as you can see, okay, and you can see that this face, this face, and the faces on the other side of the, and the names are not split.

We can do it later. This is for the solid parts, as you can see, that is here. Let's do the splitting here. I choose this face here, and then I go here for splitting, for separating the faces. I can do it here; you can see that now I have new faces at the two ends.

If you want to see that, okay, now this is the only face that I have, this is the face for this side, and for the other side is this one. Okay, let's go and name this. If you want to rename this phase, click here, and I can choose a different name here.

Say that, for example, I want to set this to "inlet". And I can set the boundary type instead of wall, which is the default boundary condition, go for velocity inlet, and say ok.

And for the other side, again, I rename it, I change the name to "outlet", set the boundary condition to pressure outlet, and for this side, change the name to say that "wall1" and set this to wall.

So, if you click here, you can see that I have this one, it is "inlet" and velocity, inlet is the type. This one it is the "outlet" and the type it is pressure outlet. And this one it is "wall1" and the type it is wall.

So, now I can update the region for boundary layer, let's see that if I have the zones or not correctly added the inlet, the inlet outlet, and whatever that I have, see this is "inlet". This is "outlet", we have it, and this is "wall1".

And this is another one, for the solid that I haven't shown this here. So, if I come here and say that choose everything and display, ok, so this is the solid parts. Okay, go back to only, so add the boundary layer, and for volume meshing, just add minimum orthogonality condition to 0.15 and update.

Okay, let's see the volume meshing at the walls. You can see that we have a boundary layer, no boundary layer at the inlet or outlet, but where we have the solids, you can see that we have the boundary layer forming. You can see that.

So, here we could define inlet, outlets, boundary condition, and the walls. Let's just save this mesh and go for seeing what we have in Ansys Fluent. Okay, let's start Ansys Fluent. This is an Ansys Fluent model; if you check the model, you can see that we have "inlet", "outlet".

Please be sure to correct any misspelled Ansys product names as you transcribe. If you want to display that, you can display that. This is "inlet", velocity inlet. I can assign velocity here. If I want to see "outlet", then this is "outlet". "Outlet", display that.

You can see that this is the "outlet" and pressure outlet. And "wall1" is this one, this is "wall1", that we have it. And if we want to see the solids, ok, for sure, we have wall and shadow wall because it is the solid and fluid domain interface.

So, if we say that, for example, this is the solid part, let's show this, you can see that here, and this is the solid part.

So, we could define inlet, outlet, and wall boundary conditions in Ansys Fluent Meshing, and not done here, we don't have the name selection here for inlets or outlets that we have; we usually do this in this way in Ansys Discovery, but I just show you that you have to do this in Ansys Fluent Meshing.

So, hopefully, it could help you to work faster sometimes with CFD simulation. Please contact us at https://ozeninc.com/contact for more information.