[kaboka]

Hello,

I would like to define a velocity inlet in 45-degree angle for my quenching multiphase flow (water and air) case in 2D. I have tried to give the axial and radial velocity to inbuilt system, however it does not give me the exact solution. Could anyone help me about it? Do I have to add a UDF file or is there any other tricks you could recommend?

Following pictures are my actual case and the velocity vector that I want:

https://imgur.com/bSpbkGc
https://imgur.com/ixaruoy

Thanks in advance
Bora

[Guvennergiz]

Hi Bora,
I am not sure but;
First of all, you need to divide the inlet section into two parts (from middle ofc). Then define the direction vectors and speed inputs one by one. Like in the screenshot below (in this coordinate system your velocity vectors can be X=1/Y=1/Z=0 and X=-1/Y=1/Z=0).
I hope that this can be a solution of your problem.
Best regards,
Güven

[kaboka]

Originally Posted by Guvennergiz

Hi Bora,
I am not sure but;
First of all, you need to divide the inlet section into two parts (from middle ofc). Then define the direction vectors and speed inputs one by one. Like in the screenshot below (in this coordinate system your velocity vectors can be X=1/Y=1/Z=0 and X=-1/Y=1/Z=0).
I hope that this can be a solution of your problem.
Best regards,
Güven

Hi Güven,

Thanks for your answer, as my case is a 2D axisymmetric I don't have a coordinate system section in velocity window. I need an conical velocity profile which has a 45 degrees angles. I tried the following method but it doesn't give me a good solution. I'd be appreciated if you have any idea about that situation.

Bests.
Bora

[AlexanderZ]

axial^2 radial^2 component together should give you 1

also you can use other reference frame, not absolute

[kaboka]

Hi AlexanderZ,

Thanks for your advice but that didn't work. However, I found a way to define both axial and radial velocity with a Udf code individually. In Fluent, velocity vectors look good as you can see in the attachments, but when I load results to the CFD_Post it does not give the good conical spray nozzle shape. Do you have any idea what is the reason of this problem?


Bests,
Bora

[Guvennergiz]

Originally Posted by kaboka

Hi AlexanderZ,

Thanks for your advice but that didn't work. However, I found a way to define both axial and radial velocity with a Udf code individually. In Fluent, velocity vectors look good as you can see in the attachments, but when I load results to the CFD_Post it does not give the good conical spray nozzle shape. Do you have any idea what is the reason of this problem?


Bests,
Bora

Hi Bora,
Glad to hear you solved your main problem.
Maybe you should run your case a bit longer to get fully developed region?
Best regards,
Güven

[kaboka]

Originally Posted by Guvennergiz

Hi Bora,
Glad to hear you solved your main problem.
Maybe you should run your case a bit longer to get fully developed region?
Best regards,
Güven

Hi Güven,

Unfortunatelly I have tried that as well but that was not the case. I am still trying to find the best solution here. If anyone have any idea about that I'd be very appreciated. In order to make it clear I add one more volume fraction picture on CFD-Post and what I want it really. Thanks in advance.

Bests,
Bora