Menu

Discussion Forum

New Discussion
Filter

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

2D flow solution plots

Posted Sep 9, 2011, 2:01 a.m. EDT Version 4.2 5 Replies

Kumar
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,

I had posted a couple of days ago about modeling a microfluidic channel with 2D flow through it.

The channel is created in a plastic cube and the cube is bonded on to a thin glass plate.

The plate is heated from below by a metallic strip and I would like to see the temperature profile across the fluid
(first stationary, then time dependent).

No matter what boundary conditions I impose, I get an error saying no solution could be found and I see that the plots are unrealistic.

I have checked the geometry and the material properties and they are okay.

How can I couple the heat flow from the source with the fluid flow?

Can you suggest any other corrections?


5 Replies Last Post Sep 13, 2011, 10:40 a.m. EDT
Lechoslaw Krolikowski
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 9, 2011, 7:13 a.m. EDT
Hi,
To couple the heat transfer with the fluid flow use Non-Isothermal Flow or Conjugate Heat Transfer.
Hi, To couple the heat transfer with the fluid flow use Non-Isothermal Flow or Conjugate Heat Transfer.
Kumar
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 9, 2011, 5:14 p.m. EDT
Hey,

Thanks for your reply.

I tried using conjugate heat transfer but I still cannot get a solution. Not even for a stationary setup.

I tried it for a simple flow across a horizontal channel with an inlet flow rate.

Strictly speaking, I do not need a condition at the outlet but I tried it with an outlet velocity as well.

Is there something I am missing in the settings?

Hey, Thanks for your reply. I tried using conjugate heat transfer but I still cannot get a solution. Not even for a stationary setup. I tried it for a simple flow across a horizontal channel with an inlet flow rate. Strictly speaking, I do not need a condition at the outlet but I tried it with an outlet velocity as well. Is there something I am missing in the settings?
Lechoslaw Krolikowski
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 10, 2011, 6:04 a.m. EDT
Hi,


Is there something I am missing in the settings?


It is difficult to say without insight into your *.mph file.

Hi, [QUOTE] Is there something I am missing in the settings? [/QUOTE] It is difficult to say without insight into your *.mph file.
Kumar
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 12, 2011, 5:32 p.m. EDT
Hi,

I have attached the mph file for the model.

Could you take a look at it and tell me what I am missing?

Thanks.

Hi, I have attached the mph file for the model. Could you take a look at it and tell me what I am missing? Thanks.

Attachments:

Lechoslaw Krolikowski
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 13, 2011, 10:40 a.m. EDT
Hi,

I've reviewed your model1.mph file. I have the following comments and advice.

* Conjugate Heat Transfer node *
- Inlet subnode. The flow rate 0.0001m3/s is unrealistically high.
- Outlet subnode. Boundary condition: Instead of Laminar outflow select Pressure then set, say, 1atm.
- Add the Temperature subnode. Select boundary 6. Set the temperature of the inflowing water (say 293K).
- Add the Outflow subnode. Select boundary 18.

* Mesh node *
Apply denser mesh. Try Extremly fine instead of Fine.

I hope that this will help you.

Best regards,
Andrzej









Hi, I've reviewed your model1.mph file. I have the following comments and advice. * Conjugate Heat Transfer node * - Inlet subnode. The flow rate 0.0001m3/s is unrealistically high. - Outlet subnode. Boundary condition: Instead of Laminar outflow select Pressure then set, say, 1atm. - Add the Temperature subnode. Select boundary 6. Set the temperature of the inflowing water (say 293K). - Add the Outflow subnode. Select boundary 18. * Mesh node * Apply denser mesh. Try Extremly fine instead of Fine. I hope that this will help you. Best regards, Andrzej

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content