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2D simulation for mixing two non-reacting gases

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Old   July 5, 2011, 08:11
Default 2D simulation for mixing two non-reacting gases
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arun mishra
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I want to carry out a simulation for mixing two non-reacting gases, methane and hydrogen. Methane is allowed to enter a mixing chamber with a diameter of 35mm by a tube of 7 mm dia and hydrogen is allowed to enter the chamber from two tubes of 7mm dia normal to the methane tube. Both the gases are at 200 bar.
Can anyone suggest me how to do the simulation for these gases. I need minimum pressure drop and maximum and homogenuity in the resulting gases.
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Old   July 5, 2011, 09:01
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Adrien Lemoine
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The mutliphase models that should be used are : Volume of Fluid or Eulerian.
eulerian is a bit slower.
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Old   July 5, 2011, 09:51
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Quote:
Originally Posted by AdrienL View Post
The mutliphase models that should be used are : Volume of Fluid or Eulerian.
eulerian is a bit slower.
I am using two diff gases(methane and hydrogen for my model). I dont think the multiphase model would be useful here.
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Old   July 5, 2011, 10:20
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My bad, you can't use Volume of Fluid but Eulerian works perfectly
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Old   December 13, 2011, 16:51
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Dear Arun,

how did you solve your mixing analysis?
I am facing the same problem, I have a nozzle ejecting air into a pipe containing gas. I am interested in the mixing of the two materials. How can I handle this? Which model should I activate in Fluent (Transport of species, Eulerian, VOF, ...)?

Thank you very much for your reply.

Sergio
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Old   December 14, 2011, 13:01
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Hello

Why not multispecies (with no reaction) only? For two gas species, you'll have two continuity equations, but only one for momentum, and energy. The turbulent mixing will do the rest


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Old   December 16, 2011, 06:21
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Dear Doronzo,

I am not familiar with multispecies model, but it seems to me the Eulerian multiphase model can account for fluid-fluid mixing (even if both fluids are gases) and the multispecies is dedicated more to chemical species (i.e., for each gas I have to define its chemical composition).
Since I am not interested in single species distribution (each gas is composed of several species), I guess the multiphase is the most appropriate.

What is your opinion on this?

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Old   December 16, 2011, 08:50
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are the two fluids miscibile or immiscible? regards
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Old   December 16, 2011, 11:05
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One fluid is air, the other is syngas composed of n2, 02, co, co2 and other species. They are miscible in the sense that they can penetrate each other but they are not reacting.

Which model would you use, multispecies or multiphase? If you suggest to use the multispecies, should I define each single species for both fluids?

Thank you very much!

Serse
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Old   December 16, 2011, 15:48
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I would use multispecies, with two species, one/fluid. The non-reacting mixing will probably depend on turbulent mixing, and in each cell you will have volume fractions for the two fluids.

In case of immiscible fluids, VoF would be probably necessary, although Eulerian multiphase can be also used, but I would use multispecies only
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Old   December 20, 2011, 09:11
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Hello,

I am using the species transport model how you suggested, and it works perfectly! I specified one syngas-air mixture where syngas is composed of one fluid (syngas) and air is composed of two fluids (nitrogen and oxygen as from Fluent database). The mixture has ideal gas behaviour for density calculation as air is entering the system through a nozzle where it undergoes adiabatic expansion. The solver is density-based. I have also included the k-e realizable turbulent model.

Next step will be to include transfer of heat from/to walls by convection and radiation. If you have any tip to provide on this, please reply.

Thank you very much.
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Old   November 22, 2012, 19:18
Default mixing air and methan in a tee
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shahrouz mohagheghian
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Hi
I am working on a project, air and methane are entering a tee from two different sides and the mixture is leaving the geometry from the other side, can eny one help me with it?
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Old   April 26, 2013, 16:14
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arun mishra
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Hello every1.. I have stopped working on Fluent. And sorry every1 for not being able to reply as I have not used this forum for quite a long time
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Old   January 30, 2015, 04:53
Question qubic chamber with hydrogen release
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Hi every1
I have similar prob
my problem is a qubic chamber filled by air and hydrogen leaks to it from a small hole in the bottom,
what model is appropriate 4 this prob
regards
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Old   July 27, 2015, 05:59
Default Non reactive gaseous simulation
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Hello

I intend to study the mixing of two gases in aa non-reactive environment and i find the current discussion related to the activity I am pursuing.

Firstly, as per the discussion till now in this forum, I guess species model is more appropriate.

Secondly, using the model and the boundary conditions, which result could we expect and how would we quantify the extent of mixing using these results.

Lastly, can anyone upload a related tutorial in Fluent/CFX platform.

Thank you in advance
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