In problems involving multiple fluid domains , if i define,for eg, air as the fluid in first domain and water as the fluid in the second domain, then automatically the fluid in the first domain changes to water.can anyone tell where the problem lies? Thanks in advance

Hi, you should specify, when meshing your domains, two different materials. If the material in your mesh is same, you cannot specify two different materials. Which mesher do you use?

Ciao Davide

Dear Sumedh,

By default ANSYS CFX-Pre keep the Fluids List within fluid domain the same on all the fluid domains. This is called "constant physics" for fluid domains.

However, if you want to have different materials for disconnected fluid domains, you can do that by disabling "constant physics".

In ANSYS CFX-11.0, you can do so by

1 - go to Edit/Option/CFX-Pre and check your settings.

2 - right click on Simulation Type, and I believe you can enable/disable it there as well.

3 - Use the old enviroment variable CFX_NO_CONSTANT_PHYSICS and set it to 1, or T

You can search for in the forum for similar postings as well.

Very IMPORTANT.. When constant physics is disabled, CFX-Pre no longer enforces that models are consistent for connected fluid domains. For example, if you change one fluid domain from Laminar to SST, you must manually fix all connected fluid domains; otherwise, the solver will fail with an obscure message. Opaque

thanks a lot. I have made two different bodies in ICEM before meshing, the problem is coming in pre.

Thanks a lot. I would try this out.This seems to be very helpful.

[srinath_cfx]

Hi,

I am running ANSYS CFX-13.0. In the CFX menu bar 'edit->options->CFX-pre->general', I have 'ticked' the 'enable beta physics' and 'un-ticked' the 'constant domain physics'.

For time being I have to run the shock tube problem for 2 different gases say helium (driver) and air (driven). How do I add the materials in CFX-pre? Is it a homogeneous mixture or a pure substance?

Thanks.

[Volumeoffluid]

Originally Posted by ParodDav
;81323

Hi, you should specify, when meshing your domains, two different materials. If the material in your mesh is same, you cannot specify two different materials. Which mesher do you use?

Ciao Davide

Hi,
how specify my materials before meshing???
i use DesignModeles, Ansys Meshing, Fluent Ansys 14.5
Thank you in advance!

[gbrajtm]

I was trying model the laminar flow analysis,

One Thin film region is Gas, another region is CO2, both are flowing in opposite direction, I am not able to specify the two materials for the respective two region. Could you help, how to do it. Attached fig

[Opaque]

http://www.cfd-online.com/Forums/cfx...-material.html

[skumar112]

Originally Posted by ParodDav
;81323

Hi, you should specify, when meshing your domains, two different materials. If the material in your mesh is same, you cannot specify two different materials. Which mesher do you use?

Ciao Davide

Hello I am having the same problem on fluent using the meshing tool in Ansys Fluent 17.2

[ghorrocks]

Try the fluent forum.