[john c]

Hi All,

I am very new to CFD and using ANSYS for a project that I am working on. For my project I have two cylinders, one inside the other. The inside cylinder represents a rotational domain, while the outside represents a stationary domain. I understand that in order to use Fluent to see how the flow behaves I need to create an interface between the two domains, I am using the surface of the inner cylinder as the interface. Here is where my problem lies, as far as I understand the interface has to have two faces, one being on the rotational side and one being on the stationary side, is this true? Or can I just have an interface with just one face?

If I have to have two faces for the interface, I cannot figure out how to click on the inner face of the inner cylinder. I have suppressed the outer cylinder in order to click on the outer surface of the inner cylinder to create one portion of the interface but I cannot figure out how to click on the inner portion of the cylinder to create the second face (again, if even needed).

So, to summarize, does my interface have to have two faces, one on the inside of the inner cylinder that represents the rotational domain and one on the outer part of the inner cylinder that represents the stationary domain? And if so, how can I pick the inside of the inner cylinder to assign the interface.

Thank you all for taking the time to read through this, again I am a bit of a novice with CFD so please pardon my ignorance and feel free to ask any additional information.

[vasava]

Your understanding of the interface is correct.

Yes, you need two surfaces to make an interface.

I am not familiar with ICEM but you can try this.
1. Create mesh without interface in ICEM. Make sure you have two separate zones and both are declared as fluids.
2. In fluent declare the boundaries in question as interface.
3. In 'Create/Edit Mesh Interfaces Dialog Box' create the interface.

[stuart23]

When you import it into Fluent, the solver will split the domain into "The-name-of-your-interface" and "The-name-of-your-interface-shadow". Then specify the boundary condition as "interior" and Fluent will merge the zones. EASY!

Stu

[john c]

Thank you guys...I appreciate both of your responses

[Maralady]

I am having a hard time creating the interface at the mesh, in both 2D and 3D, can you guys help me please?

[olivlly]

Originally Posted by john c

Thank you guys...I appreciate both of your responses

do you have solved this problem? how did you set the interface, use the inter and outer face of the inter cylinder? then how to choose the inter face of the inter cylinder? I can not see the “shadow” of it when imported into fluent, or any interior BC in the fluent. can you give any suggestion? thank you!

[SSG_NJ]

Originally Posted by stuart23

When you import it into Fluent, the solver will split the domain into "The-name-of-your-interface" and "The-name-of-your-interface-shadow". Then specify the boundary condition as "interior" and Fluent will merge the zones. EASY!

Stu

Doesn't FLUENT only create shadows for walls separating a continuous fluid domain?

I haven't been able to get FLUENT to create a shadow for an interface BC I defined in ICEM.

Any help is appreciated!