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VOF tracking of droplet

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Old   May 29, 2013, 03:21
Default VOF tracking of droplet
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Hi

I have a channel of 50 micro x 50 micro x 1000 micro square channel.I am using VOF method to track the droplet movement.Secondary phase is water and primary phase is oil.The flow rate of oil is 50 micrlitre/min. I patch the secondary phase a sphere of diameter 25 micron inside the primary phase.How can i move the water droplet by the drag force of oil.I want to find out the change in pressure drop by the movement of this droplet inside the channel.

I am using transient simulation
Geo construct,explicit,first order upwind, pressure velocity coupled with volume fraction,Presto as the scheme

Even i did the simulation my droplet is not moving

My time period was 1e-7 with 3000 steps


Please help me\\\\\


Thanks

Sajeesh
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Old   May 29, 2013, 07:58
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EMAVI V SURYA SAMPATH
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Hello,

Genrally for droplet simulation, i think people use DPM instead of VOF..
You sure, you should use VOF for your case ?
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Old   May 30, 2013, 00:02
Default Usage of DPM
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Sir

Thanks for your reply.Initially i used DPM for the simulation then i could not control the number of droplet in my domain .Also how we will define a droplet with out droplet colescence and break up..Droplet thing can not be used in injection window.I am also not getting the exact velocity of droplet in the domain..When ever i am injecting the particle attains the maximum velocity of the fluid.This velocity will achieve only at the steady state situation..I have some doubt in that method.If you help me in DPM,i can switch over to DPM..Thanking You


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Old   May 30, 2013, 03:03
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for cing the droplets in injections, you have to enable species -- species transport.
I think, you missed this step.

Try enabling, Define-- Species-- Species transport

Now check ur injection window, you will find droplet. There give injections by surface and select the surface from where injections are occurred,


So, first enable species, the n DPM, then injections.

is your case 1 way coupling ? or two way coupling ? and wots the volume fraction you considered. ?
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Old   May 30, 2013, 10:53
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sir

Thanks for reply i need two way coupling of water droplet and oil (continous phase)


I need the tracking of the droplet.Waht is the velocity of the droplet after reaching steady state condition when the droplet is driven by the continous fluid.

Thanks
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Old   May 30, 2013, 10:59
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sir
I switch on the species transport on.But still the droplet is not coming.That option can not be selected.Here i dont want the diffusion of droplet .so what option i should select in the species transport model.


Thank you
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Old   June 10, 2013, 11:28
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Quote:
forcing the droplets in injections, you have to enable species -- species transport.
I think, you missed this step.
If you are not interested in modeling the evaporation/boiling/combustion, you need not use droplet as particle type. Use "Inert" which doesn't necessitate the species to be specified.

OJ
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Old   June 11, 2013, 02:10
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Thank you sir
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