Simulation Mechanical and Multiphysics

Distinguished Contributor
Posts: 138
Registered: ‎09-22-2008

mix fluid flow

659 Views, 5 Replies
01-29-2010 01:00 AM
Hi, I'd like to know if there is not possibility to simulate the mixture of two fluid.

Thank u in advance

Marco Girardi
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Product Support
Posts: 167
Registered: ‎11-12-2009

Re: mix fluid flow

02-17-2010 06:04 AM in reply to: subpartner

One can use Algor's CFD to consider mixing of similar fluids (same density), but not the mixing of fluids of different densities. It is, however, possible to consider differnet fluids (of different densities) in a single fluid flow analysis for which the fluids do not mix.

Pat Tessaro, P.E.
Autodesk Inc.
Pat Tessaro, P.E.
Customer Support Engineer

Autodesk, Inc.
285 Kappa Drive
Suite 250
Pittsburgh, PA 15238
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Posts: 259
Registered: ‎06-14-2010

Re: mix fluid flow

06-14-2010 12:11 PM in reply to: PipePakPat


Algor fluid supports mixtures with same fluid (including density and viscosity etc), but not supports mixtures with different material which belongs to territory of multiple-phase flow.


Jianhui Xie, Ph.D
Principal Engineer
MFG-Digital Simulation
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New Member
Posts: 1
Registered: ‎10-05-2011

Re: mix fluid flow

10-05-2011 12:50 PM in reply to: PipePakPat

"One can use Algor's CFD to consider mixing of similar fluids (same density), but not the mixing of fluids of different densities." - Pat Tessaro 2/2010




Does this also hold true for the newer program Autodesk Simulation Multiphysics 2012?



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Posts: 3
Registered: ‎05-17-2013

Re: mix fluid flow

05-17-2013 05:58 AM in reply to: zakatackk



is it stil not possible to mix two different fluids ?

the help says the following: 


  • For mixing, an alternative (approximate) strategy is to use a general scalar boundary condition, and vary the fluid properties (density and viscosity) with the scalar concentration.

what does that exactly mean ? density or viscosity cant be changed, even when trying two similar fluids with different colors set, the error of impossible mixing is given.

is there a possibility to visualize a mixing between 2 gases with different vol - oder massflows ? 


thank you.

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*Expert Elite*
Posts: 570
Registered: ‎08-30-2012

Re: mix fluid flow

05-17-2013 07:27 AM in reply to: Henka85

I believe the statement that you found is for the product "Autodesk Simulation CFD". Sim CFD is a separate product from Sim Mechanical/Sim Multiphysics, and they have their own message board. So if you want to pursue the simulation of mixed fluids, I suggest that you post to their discussion group.


Simulation Multiphysics does have a fluid flow analysis type which is completely independent of Sim CFD. Sim Multiphysics cannot simulate different fluids mixing. I do not recall reading any suggested work arounds or approximations for Sim Multiphysics.

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

Simulation Mechanical user since Dec 1997
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