CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Multiphase charging interFoam question

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   March 9, 2007, 12:17
Default hi all, i am interested in
  #1
Member
 
Anthony Costa
Join Date: Mar 2009
Posts: 40
Rep Power: 8
coastal593 is on a distinguished road
hi all,

i am interested in simulating a simple system in which a water droplet impacts a film of water/some other fluid on a surface. i have solved the water-impacting-water system with interFoam and the results look quite nice. i have 3 questions about how to move forward with this ...

1) i am interested in incorporating charge into my droplets, specifically in relationship to the possibility of rayleigh-explosion events due to local radius of curvature changes in the droplet upon transport and collision. anyone have any thoughts on this possibility? i'm not sure how to incorporate this or if it's currently possible.

2) i am very interested in >2 phase systems, and i see that a arbitrary phase solver is currently slated to be released with 1.4. is the any way to play around with this before official release?

3) currently my droplet starts out in rectangular form but quickly "sphericalilizes" itself due to surface tension. is there any way using setFieldsDict to indicate a spherical droplet instead of a box? right now this doesn't much matter but in a case of charged droplets this might be a big deal.

thanks very much!
anthony
coastal593 is offline   Reply With Quote

Old   March 9, 2007, 13:12
Default Hi Antony I'm developed a sim
  #2
Member
 
Marco Moscaritolo
Join Date: Mar 2009
Location: Bergamo, Italy
Posts: 33
Rep Power: 8
mavimo is on a distinguished road
Hi Antony
I'm developed a similar case (a drop impact over wall), about question 3 I had subdivide sphere with 4 rectangles similar to:


Simmetry plane
*****|
*****|___
*****|___|_
*****|*********|_
*****|*********|**|
*****|*********|_|
*****|_____|
*****|___|
*****|


You can increase number of rectangle to simulate a sphere.

Bye
Marco
mavimo is offline   Reply With Quote

Old   March 9, 2007, 13:33
Default Hello, Regarding the charge
  #3
Member
 
Pierre Le Fur
Join Date: Mar 2009
Location: UK
Posts: 60
Rep Power: 8
pierre is on a distinguished road
Hello,

Regarding the charge thing, I am not sure what you mean. Is it an ionised droplet phenomenon or the so-called micro-explosion of droplet when evaporation occurs.

For setting an initial field, well you can define a droplet centre cell and then loop through all cells of the domain and give them gamma = 1 if they are within a given distance (droplet radius of that seed cell) something like

Info<< "Reading field gamma\n" << runTime.timeName() << endl;

volScalarField gamma
(
IOobject
(
"gamma",
runTime.timeName(),
mesh,
IOobject::MUST_READ,
IOobject::AUTO_WRITE
),
mesh
);

vector dropletCentre = vector(1.0, 1.0, 0.0);
scalar radius = 3.0;
const vectorField& centres(mesh.C());

forAll(gamma, cellI)
{
if(mag(centres[cellI] - dropletCentre) < radius)
{
gamma[cellI] = 1.0;
}
}

Pierre
pierre is offline   Reply With Quote

Old   March 9, 2007, 13:56
Default thanks for your info on no. 3
  #4
Member
 
Anthony Costa
Join Date: Mar 2009
Posts: 40
Rep Power: 8
coastal593 is on a distinguished road
thanks for your info on no. 3 i will give that a whirl.

regarding charge: currently in interfoam i am not dealing with evaporation so it would not be induced this way. to my knowledge interfoam has no mass transport abilities. however, certainly evaporation does occur and an implementation of both the ionized droplet transport and evaporation/rayleigh-explosion would be of interest.

currently though i am most interested in the possibility of charge-repulsion within a droplet and how that might evolve in the transport of these droplets to a film and upon collision.

thanks,
anthony
coastal593 is offline   Reply With Quote

Old   March 12, 2007, 07:46
Default About question 3 you can see
  #5
Member
 
Marco Moscaritolo
Join Date: Mar 2009
Location: Bergamo, Italy
Posts: 33
Rep Power: 8
mavimo is on a distinguished road
About question 3 you can see this page.

bye
Marco
mavimo is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
InterFoam mass conservation question msrinath80 OpenFOAM Running, Solving & CFD 5 December 9, 2013 02:19
Question on InterFoam moving mesh capabilities ziv OpenFOAM Running, Solving & CFD 0 April 23, 2008 09:11
Particle charging Marijo FLUENT 0 October 23, 2006 11:40
multiphase modeling question liang FLUENT 0 December 3, 2005 15:40
CFD Code (Charging Processes) Sherard Main CFD Forum 0 July 29, 1999 12:29


All times are GMT -4. The time now is 17:53.