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Eulerian Wall Film model with Eulerian disperse phase

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Old   August 29, 2013, 16:48
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Shawn Fotovati
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I started the EWF and DPM from a converged solution.

How can I get the tutorial? I checked online, and I could not find it. Do you any address or reference for any possible website?

Thanks
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Old   August 29, 2013, 18:59
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Shawn Fotovati
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I found the problem. If I run it on Parallel, it crashes. Now I have turned it to Serial Processing and now it is fine. Can anyone tell me how to set it for parallel?

Thanks
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Old   October 1, 2013, 17:47
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Jing Shi
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Hi all,
I am trying to simulate oil-water two phase flow in a pipe. As the oil is very viscous, say 5000cP, there is oil fouling film on the pipe wall (see the figure attached). I used VOF before, could get similar flow pattern, but no film at all.

I wander, first, could VOF simulate the film?
and second, could EWF coupled with Eulerian mutiphase model simulate it? It seems for EWF, the second phase should be dispersed, while for the core annular flow pattern I am trying to simulate, the oil core is not dispersed. (I'm having a try on it, but the calculation is extremely slow)

Anyone could give some instructions? Many thanks

Regards,
Jing
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File Type: jpg Oil_core_water_annulus_with_oil_film.jpg (33.7 KB, 84 views)
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Old   October 1, 2013, 18:01
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Shawn Fotovati
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You can couple EWF with Eulerian multiphase. Just turn multiphase flow on with Eulerian, and then in EWF make sure you have activated the phase accretion. In order to consider second phase mass, momentum, and energy conservation, you have to write a UDF for source terms in the second phase. You can use following macros for this purpose:
Collect_Film_Phase2_Sources(c, ct, ds, PHASE2_MASS)
Collect_Film_Phase2_Sources(c, ct, ds, PHASE2_MOM_X) [similar for y, z directions]
Collect_Film_Phase2_Sources(c, ct, ds, PHASE2_HEAT)

You can find many other macros in sg_film.h

Good luck

Shawn
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Old   October 22, 2013, 15:01
Post Spray with Eulerian Wall Film model
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Venkat
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Hello,
Please see the attached image. The spray (water) impinges on the walls of vessel, and starts to entrain air inside the vessel. The entrained air that esaceps through the annular gap between the two vessels should shear the water film and thus cause leakage. The objective is to calculate the leakage of water through the gap between the vessels.

I have set up the spray setting for a solid cone, through DPM & Injection. I have enabled Eulerian Wall Film model although not entirely sure of what is gives me. For all the walls, the DPM boundary condition is wall film (not escape or trap or reflect) with zero splashing, and enabled Eulerian Wall Film.

Please can any one suggest if I am going in the right direction.
I am not too sure as to how many particles I should inject. I know the mass flow, velocity of the nozzle, spray cone angle etc.
Please pour in your thoughts and any suggestions to improve the model set up accuracy will be appreciated!
Thanks,
Venk
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Last edited by Venk; October 23, 2013 at 09:17. Reason: Something is missing in attachment
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Old   June 12, 2015, 17:03
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aah
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Hello,
I'm trying to model absorption of plane orifice atomizer droplets and forming wall film, usin DPM and EWF. at first i started using DPM and all the things were ok: droplets generates and travel at air stream. then I activated EWF and select DPM colletion option. right after that, the dpm droplets decreases and all of them remain near the atomizer and do not travel along the air stream...
I tried a lot and changed different parameters, but I could not find the problem....
please help....
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Old   December 6, 2016, 08:39
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Evangelos Antoniou
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Hello,
I would like to ask whether there are experimental data of this phenonmenon (multiphase flow air and water droplets - development/ formation fluid/ liquid film) which can be compared with the data of a simulation.
Thank you in advance.
Evangelos
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Old   January 6, 2017, 07:15
Exclamation Wall Film Model in ANSYS-CFX
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Ibadullah
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Hi everyone its good to read conversation of all of you regarding Eulerian wall film model in Fluent. I just need to know that is it possible to see the water film deposition on a wall of a object and its effect on droplet dispersion in ANSYS-CFX. Suggestion would be highly appreciable.
Thank you.
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