Help needed in 3D multiphase micro model

ehsanfareed · November 25, 2009, 05:52

Hi All,
I have a T shape (3D) micro channel, from the left air enters and from below water enters (both are velocity inlets), the flow is laminar, time unsteady, VOF model. I want to see the mixing effect of air and water at the T junction. It is supposed to be a bubble formation at the junction and the bubble is then carried away with the air flow to the outlet (pressure outlet).

But what I get is that water level starts to rise in the channel and there is no mixing effect or bubble formation, I get a clear phase boundary between air and water, you can see the picture.
http://yfrog.com/ek61388547j

I dont know what is the problem, Also I want to use PTFE as a wall material to see its effect on the water as it is a hydrophobic material, but I am unable to define a User Define Material Database for PTFE. Also I want to know that which property of PTFE should be given which defines its hydrophobic character.

Please help me in the above 2 problems I am having regarding the mixing effect and the PTFE material, I shall be thankful to you.

Regards,
Ehsan Fareed

MuxaB · November 29, 2009, 19:07

Ehsan,

Looks like you are using Fluent for this problem? You should probably post your question on the Fluent forum.

Michael

November 25, 2009, 05:52	Help needed in 3D multiphase micro model	#1
ehsanfareed New Member Ehsan Fareed Join Date: Nov 2009 Location: Magdeburg, Germany Posts: 3 Rep Power: 16	Hi All, I have a T shape (3D) micro channel, from the left air enters and from below water enters (both are velocity inlets), the flow is laminar, time unsteady, VOF model. I want to see the mixing effect of air and water at the T junction. It is supposed to be a bubble formation at the junction and the bubble is then carried away with the air flow to the outlet (pressure outlet). But what I get is that water level starts to rise in the channel and there is no mixing effect or bubble formation, I get a clear phase boundary between air and water, you can see the picture. http://yfrog.com/ek61388547j I dont know what is the problem, Also I want to use PTFE as a wall material to see its effect on the water as it is a hydrophobic material, but I am unable to define a User Define Material Database for PTFE. Also I want to know that which property of PTFE should be given which defines its hydrophobic character. Please help me in the above 2 problems I am having regarding the mixing effect and the PTFE material, I shall be thankful to you. Regards, Ehsan Fareed

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
air and water vapour mixture - multiphase model	Saba	FLUENT	0	February 10, 2009 12:05
multiphase cfd model problems	zhijing peng	FLUENT	0	January 7, 2009 13:07
Multiphase flow. Dispersed and free surface model	Luis	CFX	8	May 29, 2007 18:13
multiphase mixing Problem with MRF model in MixSim	Srinivas	FLUENT	0	October 17, 2005 06:35
enabling UDS in Eulerian-eulerian multiphase model	shao1	FLUENT	0	July 14, 2002 22:23

November 29, 2009, 19:07		#2
MuxaB Senior Member michael barkhudarov Join Date: Mar 2009 Location: Sante Fe, New Mexico, USA Posts: 336 Rep Power: 18	Ehsan, Looks like you are using Fluent for this problem? You should probably post your question on the Fluent forum. Michael