CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Particle Trajectory calculation

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

LinkBack Thread Tools Display Modes
Old   February 17, 2001, 09:12
Default Particle Trajectory calculation
Posts: n/a
Hi: I use FLUENT 5.5 's Discrete Phase Modeling to simulation particle and liquid flow in 180degree bend. This is laminer flow. I wnat to get accuracy prticle residence time. I found when I control the integration time step size from big time step size to small time step size , some particle will get unstable residence particle time . I put particle near wall ,I will get unstable residence particle time when integration time step size from big time step size to small time step size When I put particle far away wall , The result is stable. Can someone have some experience when you use Particle Trajectory calculation


  Reply With Quote

Old   February 17, 2001, 15:41
Default Re: Particle Trajectory calculation
Posts: n/a
Do not use time step size for RTD. Instead, use the integration factor (?) in the same box. Use 30 - 40 to ensure that each cell is properly resolved with enough integration steps.
  Reply With Quote

Old   July 13, 2009, 13:32
New Member
christian paul
Join Date: Jul 2009
Posts: 2
Rep Power: 0
cpaul is on a distinguished road
Hi all,
I need some help with VOF modeling in fluent. We have a 2D Horizontal micro channel that is 5e-05 meters in diameter and 7.5e-04 in length and we have the primary stage set to water and the secondary stage set to a type of oil found in the fluent database. We first ran a simple flow problem with just water. We saved those results and used them when we initiated the Volume of Fluid.
Here are our paramters.

pressure based, 2D, absolute formulation, implicit formulation, unsteady time

Explicit VOf scheme, implicit body force with two phases.

Water-liquid, Gas-oil liquid

operating conditions:
Left as is, we want to know if we should change this

Boundry condition:
Inlet velocity 0.001 m/s pressure is 0, should we change this?

Solve> controls
Equations are flow and volume fraction
Pressure velocity coupling- simple
pressure: Presto
Momentum: first order upwind
Volume fraction: geo-reconstruct

We would also like to know what the benifit of Patch is, and if it is necessary in our case.
The main problem we're having is that the bubbles are the same diameter as the channel, we would like to know if there is any way we can control the amount of oil that goes into the channel so our oil droplet would be roughly 10 microns.
Also if there is a way to measure the forces acting on the bubble.
cpaul is offline   Reply With Quote


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
DPM UDF particle position using the macro P_POS(p)[i] dm2747 FLUENT 0 April 17, 2009 01:29
how to output particle trajectory coordinate data steven CFX 0 July 13, 2006 17:49
Warning 097- AB Siemens 6 November 15, 2004 05:41
Particle Trajectory calculation when particle hit yueroo FLUENT 2 February 28, 2001 05:26
particle trajectory calculation ursenbacher Main CFD Forum 2 January 28, 1999 17:15

All times are GMT -4. The time now is 12:46.