Help needed in 3D multiphase micro model

ehsanfareed · November 25, 2009, 06:52

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, 20:07

Ehsan,

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

Michael

November 25, 2009, 06:52	Help needed in 3D multiphase micro model	#1
ehsanfareed New Member Ehsan Fareed Join Date: Nov 2009 Location: Magdeburg, Germany Posts: 3 Rep Power: 18	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

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November 29, 2009, 20:07		#2
MuxaB Senior Member michael barkhudarov Join Date: Mar 2009 Location: Sante Fe, New Mexico, USA Posts: 337 Rep Power: 19	Ehsan, Looks like you are using Fluent for this problem? You should probably post your question on the Fluent forum. Michael