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2 Phase flow simulation in a T-junction microchannel |
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November 13, 2013, 04:11 |
2 Phase flow simulation in a T-junction microchannel
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#1 |
New Member
Arun Vasudevan
Join Date: Feb 2013
Posts: 6
Rep Power: 13 |
Hi. I am doing a transient laminar flow simulation to get the slug flow of 2 phase immiscible liquids in a t junction micro channel using VOF model. Its a simple 2d geometry and surface tension modelling is enabled. Whenever my timestep advances I get an error stating that the global COurant number is greater than 250. I reduced the time step to values as low as 1e-5. Still the problem persists. I also reduced the UR factors and increased the iterations per time step. (Pressure-0.2, Density-0.5, Body forces-0.5 Momentum- 0.3 As seen in some forum). The velocity seems to be fine at time 0 but drops to zero as soon as the timestep advances. I have included the snapshot. Can somebody help me?
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November 13, 2013, 04:36 |
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#2 |
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Alex
Join Date: Jun 2012
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November 14, 2013, 01:01 |
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#3 |
New Member
Arun Vasudevan
Join Date: Feb 2013
Posts: 6
Rep Power: 13 |
Thanks for the reply. Its 0.8mm microchannel t-junction. I have two opposite inlets one of kerosene and other water. Both with velocity ranging from 0.02-0.1 m/sec. So what would be the estimated time step size?
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November 14, 2013, 04:20 |
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#4 |
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Alex
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November 21, 2013, 01:55 |
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#5 | |
New Member
Arun Vasudevan
Join Date: Feb 2013
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Quote:
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November 21, 2013, 09:47 |
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#6 |
Super Moderator
Alex
Join Date: Jun 2012
Location: Germany
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Would it be such a mayor inconvenience to reduce the time step size to lets say 10e-8s just to see if the error is really related to the time step size?
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November 21, 2013, 17:00 |
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#7 |
Senior Member
Join Date: Jan 2010
Location: Germany
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Could you please give more input about your Simulation?
-Reference density -I think you are using a tracking method (explicit that's why CFL-dependency) Geo-REconstruct -Are both phases well separated like a normal slug flow simulation or do they interpenetrate each other? Are small bubbles and liquid entrainment expected to occur or not? -Which interpolation of Pressure are you using? -Reference Location of the operating Pressure -Operating Pressure.. |
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November 21, 2013, 17:53 |
"Monitoring bubble rising velocity in Fluent"
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#8 |
New Member
Ali Masoudi
Join Date: Nov 2013
Posts: 4
Rep Power: 12 |
Hi,
Does anybody know how can I monitor the rising velocity of single bubble in fluent? |
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August 27, 2019, 13:22 |
vof modeling in micro channel in fluent
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#9 |
New Member
maryam
Join Date: Jul 2017
Posts: 10
Rep Power: 9 |
hi
i am simulating a model with two vents and one outlet.the water patched into the main chamber and air can goes in and out from two vents. i want to simulating water flow in channel. i dont have any parameters in vents what is the best boundary condition for them? the vents are in the atmosphere pressure but the whole model is rotating so i dont know the gauge pressure=0 in correct for these vents or not? i use the out flow for outlet which it is incompatible with pressure boundaries. i cant see the right flow in channel is there any one could help me? the residuals cant decrease enough and continuity residuals are in order of 10 i appreciate your recommendations |
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slug flow |
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