Why? Preferred droplet track in Two-Phase flows

February 2, 2000, 05:39

We have analized droplet tracks simulated with the lagrange model in Star-CD and we have found preferred direction of the moving droplets, which fly vantaged through cellcenters and avoid crossing cellborders if there is a small angle between droplet motion and cell orientation. What is the reason for this effect? Thank you for your help. Maurice

February 7, 2000, 15:48

There is at least a simple workaround for this (long known) problem. Just use a highly irregular mesh (tets).

March 31, 2000, 18:00

Maurice,

Do you have droplet collisions turned on? If so, that could be the cause. I assume Star uses a droplet collision algorithm like O'Rourke's in Kiva. In this model, only droplets within the same call can collide. The collisions either result in coalesence or inelastic bouncing. In either case, the result is to turn droplet trajectories away from the sides of cells and towards cell centers. I have a paper under review by the Journal of Computational Physics that documents this problem in Kiva, if you are interested.

Regards, David Schmidt

Mori-Nik · March 15, 2011, 06:54

Hi David,

I am tryng to implement the other possibilties of collisions in KVIA, I was wondering if you know I should introduce the new satelite drops to KIVA, grateful for any help?

mel021184 · January 3, 2012, 11:25

Hi, I'm working with kiva 3V.

I need examples for kiva 3V or kiva 4.
non engine application.
someone who can help me?
someone who has worked with kiva 3v or kiva4?
I'm trying to simulate a spray impacting on a surface.

February 2, 2000, 05:39	Why? Preferred droplet track in Two-Phase flows	#1
Maurice Kettner Guest Posts: n/a	We have analized droplet tracks simulated with the lagrange model in Star-CD and we have found preferred direction of the moving droplets, which fly vantaged through cellcenters and avoid crossing cellborders if there is a small angle between droplet motion and cell orientation. What is the reason for this effect? Thank you for your help. Maurice

February 7, 2000, 15:48	Re: Why? Preferred droplet track in Two-Phase flows	#2
Joern Beilke Guest Posts: n/a	There is at least a simple workaround for this (long known) problem. Just use a highly irregular mesh (tets).

March 31, 2000, 18:00	Re: Why? Preferred droplet track in Two-Phase flows	#3
David Schmidt Guest Posts: n/a	Maurice, Do you have droplet collisions turned on? If so, that could be the cause. I assume Star uses a droplet collision algorithm like O'Rourke's in Kiva. In this model, only droplets within the same call can collide. The collisions either result in coalesence or inelastic bouncing. In either case, the result is to turn droplet trajectories away from the sides of cells and towards cell centers. I have a paper under review by the Journal of Computational Physics that documents this problem in Kiva, if you are interested. Regards, David Schmidt

January 3, 2012, 11:25	examples for kiva 3V or kiva 4.	#5
mel021184 New Member ninguna Join Date: Oct 2011 Posts: 6 Rep Power: 14	Hi, I'm working with kiva 3V. I need examples for kiva 3V or kiva 4. non engine application. someone who can help me? someone who has worked with kiva 3v or kiva4? I'm trying to simulate a spray impacting on a surface.

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March 15, 2011, 06:54		#4
Mori-Nik New Member Mori Nik Join Date: Nov 2009 Posts: 6 Rep Power: 16	Hi David, I am tryng to implement the other possibilties of collisions in KVIA, I was wondering if you know I should introduce the new satelite drops to KIVA, grateful for any help?