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-   -   Eulerian lagrangian model (http://www.cfd-online.com/Forums/fluent/94404-eulerian-lagrangian-model.html)

shk12345 November 15, 2011 01:23

Eulerian lagrangian model
 
Hi
Can anyone help me in telling me how can i set up a eulerian lagrangian model in fluent.
Thanks in advance
SHK

raj.cfd November 16, 2011 20:16

You have to use Discrete phase models available in Fluent . The continuous phase is solved like an continuum and the secondary phase/discrete phase is solved through lagrangian method.

shk12345 November 17, 2011 13:20

Cfd
 
Kindly tell me the steps to put a eulerian langrangian model in fluent.
I am not been able to interlink the secondary phase of the DPM model with the secondary phase of the eulerian model
kindly tell me how to do that
Thanks
SHK

mali28 November 21, 2011 10:15

Quote:

Originally Posted by shk12345 (Post 332548)
Kindly tell me the steps to put a eulerian langrangian model in fluent.
I am not been able to interlink the secondary phase of the DPM model with the secondary phase of the eulerian model
kindly tell me how to do that
Thanks
SHK

Hi,

After loading the mesh file, go to the models. Select your turbulence model then select Discrete Phase. If you want the particles to exchange momentum with the continuous plahse than select the option "interaction with continuous phase". Now click the injections button. Then click create button. Add your particle properties and the way particles are injected. You may have these via spray cone, single stream etc...
Specify the position of injector (x, y and z) in the same window. Also specify the number of particle streams.

That should be it.

You can specify the physical properties of the injected particles in the Materials menu.

shk12345 November 22, 2011 08:01

Help
 
Hello
Thanks for the reply
I have one clarification. While using the Eulerian-Langrangian Model is it so that we have to on the eulerian model from define>model>multiphase>eulerian and then on the dpm model as discussed above
or

Dpm itself takes care of the eulerian and Lagrangian framework of the calculation.

and
Is that possible to use both eulerian and dpm model at the same time in fluent if yes how??

Thanks
SHK

mali28 November 22, 2011 14:48

Quote:

Originally Posted by shk12345 (Post 333077)
Hello
Thanks for the reply
I have one clarification. While using the Eulerian-Langrangian Model is it so that we have to on the eulerian model from define>model>multiphase>eulerian and then on the dpm model as discussed above
or

Dpm itself takes care of the eulerian and Lagrangian framework of the calculation.

and
Is that possible to use both eulerian and dpm model at the same time in fluent if yes how??

Thanks
SHK

You dont have to select multiphase if you are tracking the particles using Lagrangian approach. You will need it if you want the second phase to be solved using eulerian approach.

shk12345 November 23, 2011 01:09

Help
 
Thanks for the reply but my question remains the same??
Can we use both both DPM and multiphase eulerian model at the same time.If yes how??

Thanks
Shk

mali28 November 23, 2011 05:27

Quote:

Originally Posted by shk12345 (Post 333204)
Thanks for the reply but my question remains the same??
Can we use both both DPM and multiphase eulerian model at the same time.If yes how??

Thanks
Shk

I dont know whether you can use both multiphase eulerian and DPM at the same time.

mit.R November 29, 2013 03:12

hi mali

is discrete phase (particles), turbulence always?

masoudeh March 24, 2015 23:19

Quote:

Originally Posted by shk12345 (Post 333204)
Thanks for the reply but my question remains the same??
Can we use both both DPM and multiphase eulerian model at the same time.If yes how??

Thanks
Shk


Hi, I have the same question, any one can help me please

`e` March 25, 2015 01:16

Have you tried using the multiphase Eulerian model and then enabling the DPM as well to see for yourself? I can't think of any reason that DPM couldn't be used with the multiphase model; especially if you're only concerned with one-way coupling.

masoudeh March 25, 2015 21:39

Quote:

Originally Posted by `e` (Post 538068)
Have you tried using the multiphase Eulerian model and then enabling the DPM as well to see for yourself? I can't think of any reason that DPM couldn't be used with the multiphase model; especially if you're only concerned with one-way coupling.

Thanks for your attention. Let me ask my question clearly: Is it necessary to have injection in lagragian model? Actually, I did multiphase Elurian with DPM without injection, Can I consider it as lagragian?!

By the way, I used two way coupling, what is the difference it makes compared to one way coupling?

Thanks

masoudeh March 25, 2015 21:44

Quote:

Originally Posted by `e` (Post 538068)
Have you tried using the multiphase Eulerian model and then enabling the DPM as well to see for yourself? I can't think of any reason that DPM couldn't be used with the multiphase model; especially if you're only concerned with one-way coupling.

Yes, I did Eulerian and DPM together and I got good results, but I was wandering without having injection can I consider it as lagragian!
I have problem when I add injection! Actually i am interested to have injection so that i can see particle track. can you help me please

`e` March 25, 2015 21:55

What do you mean by "injection"? If you don't specify an injection for the DPM, then you're not using the Lagrangian model (or DPM) at all.

One-way coupling is where the particles are influenced by the fluid; for example, the particles would tend toward the fluid velocity due to drag (and the speed of which is a function of the particle relaxation time). Two-way coupling also includes the influence of the particles on the fluid. Lastly, four-way coupling also considers the particle-particle interactions.

masoudeh March 25, 2015 22:08

Quote:

Originally Posted by `e` (Post 538263)
What do you mean by "injection"? If you don't specify an injection for the DPM, then you're not using the Lagrangian model (or DPM) at all.

One-way coupling is where the particles are influenced by the fluid; for example, the particles would tend toward the fluid velocity due to drag (and the speed of which is a function of the particle relaxation time). Two-way coupling also includes the influence of the particles on the fluid. Lastly, four-way coupling also considers the particle-particle interactions.

I tried to specify injections but it did not converge so I changed initial condition and finally it converged, but still the path lines are not reasonable. however the contours and other results are reasonable, can you tell me what is the problem and how can i improve it! should i increase the number of injections (now i have 3 single injections, i could not specify group injection as it was not be identified by the software and it gave me error)

Thanks,

`e` March 25, 2015 22:20

What didn't converge when you specified the injections? What initial conditions, mass flow rates etc have you specified for your injection streams?

masoudeh March 25, 2015 22:25

Quote:

Originally Posted by `e` (Post 538265)
What didn't converge when you specified the injections? What initial conditions, mass flow rates etc have you specified for your injection streams?

the software gave me the error and stop it. i specify the mass flow rate , velocity temperature ( I assume these parameters the same as the fluid) and diameter of the particle for each single injection

`e` March 25, 2015 22:31

Specifically: did the solver crash/stop during the DPM calculations or the continuous phase iterations? What error was displayed?

masoudeh March 25, 2015 22:38

Quote:

Originally Posted by `e` (Post 538267)
Specifically: did the solver crash/stop during the DPM calculations or the continuous phase iterations? What error was displayed?

after specific number of iteration it stopped, anyway i changed initial condition such as momentum pressure volume fraction and it could be helpful and it gave me the results. i just have problem with path lines which are not in the same pattern i expected! how can i work on that

`e` March 25, 2015 22:52

You can specify how many DPM iterations the solver does until it stops (the default is 500). If the particle stream hasn't escaped the domain within this number of iterations then this stream would be incomplete (finishes partway through the domain).

What path lines are you generating (show us a figure) and what are you expecting (show us another figure)?


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