Learning Forum

[Agung Limowa]

So i have the case which the duct inlet inside the tunnel or i can say it surround by fluid zone, but when i calculate on fluent it give me error like "Flotation Point Exceed" and some error. I've read few case like this and it says that the inlet couldn't be set surround by fluid zone. There's anything i can do ? 

 

There is 2 image, first its the inlet posistion and the second is outlet posistion

 

 

 

 

[Rahul]

Hello,
Hope you are doing good.

In cases such as yours if you wants to specify velocity-inlet to internal zones. For example, let’s say we have a cylinder completely inside the a box. Assume that the inside of the cylinder is meshed and have cell zone fluid-1, and outside of the cylinder is meshed with cell zone fluid-2. The inlet and outlet of the pipe is an interior type and are named interior-5, and interior-6, respectively. There is node-connectivity between fluid-1 and fluid-2 at all the boundary zones of the pipe. We know the velocity of the fluid entering.

In such a case, to specify velocity inlet to the pipe and make the fluid inside the pipe exit the domain at the outlet, follow the following procedure to accomplish this:

1. Define -> Boundary Condition. Select interior-5 under Zone and select wall on the right column under Type. Click on Yes to change the type. Two internal walls will be created, wall-5 and wall-5-shadow. ID of wall-5 will be the same as the ID of interior-5. These two new walls will be coupled by default and the available types for them are fan, interior, porous-jump, radiator, and wall.
2. A velocity-inlet type for an internal wall does not exist. In order to have types that can be applied on external zones, they need to be split. How to split wall-5 from wall-5-shadow? In the text user interface (TUI), type: /grid/modify-zones/slit-face-zone wall-5. Two additional walls will be created: wall-5, and another wall-###. A message will print on the cortex window which displays which zone is wall-###. These are now two external zones, one is adjacent to fluid-1 and the other is facing fluid-2. To have the fluid entering the pipe, the one which is adjacent to fluid-1 needs to be changed to velocity-inlet type. To find which one is adjacent to fluid-1, you need to visit the boundary condition panel for that zone and look under 'Adjacent Cell Zone'.
3. Repeat the above procedure to apply pressure-outlet if that is also an internal boundary.

Hope this helps!

[Agung Limowa]

Hi, But I have a question about meshing i named the inlet and outlet as an inlet, and it makes Fluent recognized it as an inlet and outlet, and also the fluent didn't make the cel zone, so the fluid zone is just one which is the set of model  (btw i set the duct as slice material)

 

[Rahul]

Hi
If Fluent recognizes both inlet and outlet as correct boundary conditions, then what is the issue?
Could you please elaborate more on the issue and share images of errors you are getting in Fluent/Meshing?

[Agung Limowa]

i'm really sorry but i really new to fluent and this task is really complex and so minimum source about this case

 

[Rahul]

Hi,

That's all right.

Please create a simple geometry as in my initial response and follow the procedure to make internal boundary as inlet/outlet. And then you can try the same on your actual geometry.

You can also refer to section 6.12.6Slitting Face Zone in  6.12. Modifying the Mesh (ansys.com) to know more about the operation.

[Agung Limowa]

Thankyou i will share after I try it, thankyou

[Agung Limowa]

Hi again,

I calculate and it shows this massage, i think it didn't came from meshing condition but the boundary cond. Could you identify whats wrong ?

Divergence detected in AMG solver: x-momentum Stabilizing y-momentum to enhance linear solver robustness.

Stabilizing y-momentum using GMRES to enhance linear solver robustness.

 

Divergence detected in AMG solver: y-momentum Stabilizing z-momentum to enhance linear solver robustness.

Stabilizing z-momentum using GMRES to enhance linear solver robustness.

 

Divergence detected in AMG solver: z-momentum Stabilizing pressure correction to enhance linear solver robustness.

Stabilizing pressure correction using GMRES to enhance linear solver robustness.

 

Divergence detected in AMG solver: pressure correction Stabilizing enthalpy to enhance linear solver robustness.

Stabilizing enthalpy using GMRES to enhance linear solver robustness.

 

Divergence detected in AMG solver: enthalpy

Divergence detected in AMG solver: x-momentum

Divergence detected in AMG solver: y-momentum

Divergence detected in AMG solver: z-momentum

Divergence detected in AMG solver: pressure correction

Divergence detected in AMG solver: enthalpy

Error at host: floating point exception

 

[Rahul]

The solution is diverged. Please check your mesh quality and boundary condition if they are appropriate.

[Agung Limowa]

Okay, One more question i can't check my mesh quality because it saya 

 

Error : Pressure Velocity Inlet Zone 5 have two adjacent cell