[Tempest]

Hi there!

I am new to ANSYS Fluent and I wish to model porous media using Darcy-Brinkman-Forchheimer model. I've been given an understanding that Darcy and inertial term are present in Fluent and we need to write separate UDFs for Forchheimer and Brinkman terms.

Can anyone please help me in understanding how exactly can we model DBF equation and how to write that in UDF?

Thanks in advance!

[Bruno Machado]

Originally Posted by Tempest

Hi there!

I am new to ANSYS Fluent and I wish to model porous media using Darcy-Brinkman-Forchheimer model. I've been given an understanding that Darcy and inertial term are present in Fluent and we need to write separate UDFs for Forchheimer and Brinkman terms.

Can anyone please help me in understanding how exactly can we model DBF equation and how to write that in UDF?

Thanks in advance!

The porosity profile has to be implemented through the DEFINE_PROFILE macro. If you have to add a source term in the momentum equation to implement the model, it has to be done using DEFINE_SOURCE macro.

[Tempest]

Originally Posted by Bruno Machado

The porosity profile has to be implemented through the DEFINE_PROFILE macro. If you have to add a source term in the momentum equation to implement the model, it has to be done using DEFINE_SOURCE macro.

Thank you Bruno for your quick and helpful response.

As I've already mentioned, I'm new to Fluent. Hence, the terms you are saying are familiar, but I am not conversant with the technique.

It would be very helpful if you could post a sample code or some reference where I can find the appropriate method of implementing DBF model using UDF.

[Bruno Machado]

Originally Posted by Tempest

Thank you Bruno for your quick and helpful response.

As I've already mentioned, I'm new to Fluent. Hence, the terms you are saying are familiar, but I am not conversant with the technique.

It would be very helpful if you could post a sample code or some reference where I can find the appropriate method of implementing DBF model using UDF.

have a look at the UDF manual. there are plenty examples you could use as a base to your problem.

[Tempest]

I have a problem linking the UDF with porous zone section. I am not able to find the hooking option there. If you know please tell me about this.

[Bruno Machado]

Originally Posted by Tempest

I have a problem linking the UDF with porous zone section. I am not able to find the hooking option there. If you know please tell me about this.

in your fluid domain, you go to cell zone conditions, click 'edit', check 'porous zone' and the parameters necessary to simulate the porous reagion can be defined there.

if you are adding source terms to the momentum equation, in the same box click 'Source Terms' and define it there.

[Tempest]

Thank you.
So is it that the Brinkman term will be taken care of by the porosity added in NS equation and we need to add udf only for Darcy and Forchheimer term?

[Bruno Machado]

Originally Posted by Tempest

Thank you.
So is it that the Brinkman term will be taken care of by the porosity added in NS equation and we need to add udf only for Darcy and Forchheimer term?

as you can see in the manual, the in built porosity model is defined by the Darcy's Law. Anything else has to be added through UDF.

[Tempest]

Thanks.

So is it that I need to explicitly add Brinkman and Forchheimer term?

[Bruno Machado]

Originally Posted by Tempest

Thanks.

So is it that I need to explicitly add Brinkman and Forchheimer term?

As I said in the previous post...

Anything else has to be added through UDF.

[Tempest]

Can you provide any sample code if you have any? Particularly for Brinkman term. I have written code for Fochheimer now.

[Arsalan_kh]

Hello
Nowadays I'm just working on modeling the heat transfer in a channel using porous media with a constant wall temperature.
First of all, I'm validating an article before starting my project. In the article, it has mentioned the inertial parameter and inertial coefficient of porous media by these equations:
AE= (CE*H*e)/[(K)^(0.5)]
CE=(1.75*e)/[(150*(e^5))^(0.5)]

AE=inertial parameter
CE=inertial coefficient of porous media
H=channel height(m)
e=porosity
K=permeability of the porous medium (m^2)

The value of AE=16.5 and H=1 and e=0.75 and K=10^(-4) has been considered.

This is my question. How can I add inertial parameter in porous zone area in the fluent?

( Fluent -> Cell Zone Conditions -> porous zone area )

Thanks.