CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM

Orourke collision model in DieselSpray

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

LinkBack Thread Tools Search this Thread Display Modes
Old   January 30, 2012, 06:37
Default Orourke collision model in DieselSpray
New Member
enrico bighè
Join Date: Apr 2011
Location: italy
Posts: 5
Rep Power: 11
kikko is on a distinguished road
Good morning,
I want to use the ORourke collision model for my simulation but I have see that I can set only 0 or 1 for the the coalescence it true???
if I set 1 all the particle coalesce and the diameter became too big...
If I set 0 no particle coalescence...
Open Foam don't permit me to set an intermediate value.
Does exist an intermediate case???
Is there another parameter to set for the coalescence????
Thank all for attention
kikko is offline   Reply With Quote

Old   January 30, 2012, 09:15
Super Moderator
niklas's Avatar
Niklas Nordin
Join Date: Mar 2009
Location: Stockholm, Sweden
Posts: 694
Rep Power: 25
niklas will become famous soon enoughniklas will become famous soon enough
coalescence is not a scalar, it is a boolean.
it is a flag you set if you want to allow parcels to coalesce or not.

so either you have coalescence true or false, 'intermediate' values makes no sense.
niklas is offline   Reply With Quote

Old   November 27, 2020, 12:54
Default collision and coalescence models in sprayFoam
New Member
Riddhideep Biswas
Join Date: May 2020
Posts: 29
Rep Power: 2
Rid@foam is on a distinguished road
Hello Niklas sir.
I am using sprayFoam in OpenFOAM-6 and I want to implement collision and coalescence between two particles. I have some questions regarding this, which, if you answer, it will be very helpful.
  • 1) Are there other collision and coalescence models available other than O'Rourke and trajectory?
  • 2) Is the code for coalescence for trajectory the same as for O'Rourke?
  • 3) I was studying the code in the Trajectory.C file where I found the following.
if (mag(det) > 1.0e-4)
                beta = -(n2d - n1n2*n1d)/det;
                alpha = n1d + n1n2*beta;

            alpha /= magU1*dt;
            beta /= magU2*dt;

            // is collision possible within this timestep
            if ((alpha > 0) && (alpha < 1.0) && (beta > 0) && (beta < 1.0))
What are the significances of these parameters alpha and beta in determining the possibility of collision at a particular timestep?
Rid@foam is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Water subcooled boiling Attesz CFX 7 January 5, 2013 04:32
Problems bout CFD model of biomass gasification, Downdraft gasifier wanglong FLUENT 2 November 26, 2009 00:27
help for different between les model (subgrid-scale model) liuyuxuan FLUENT 1 October 2, 2009 16:25
Grid resolution for full-scale and down scaled model gravis Main CFD Forum 0 October 2, 2009 11:27
2 stage axial turbine model convergence issues sherifkadry CFX 2 September 7, 2009 21:51

All times are GMT -4. The time now is 05:19.