Menu

Discussion Forum

New Discussion
Filter

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.

Dean Flow Modelling in MicroChannels

Posted Sep 24, 2015, 6:15 a.m. EDT MEMS & Nanotechnology, MEMS & Piezoelectric Devices, Microfluidics, Structural Mechanics Version 5.0 3 Replies

Utku Sönmez
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,

I'm trying to model Dean Flow in a Spiral Microchannel for further application of Passive Cell Separation.

Since Dean Flow is observed basically on the plane which is perpendicular to the downstream fluid flow, it requires 3D modelling of channel geometry. ( Here there is a schematic explanation: pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/Articleimage/2010/CS/b915999c/b915999c-f17.gif )

I modelled the spiral geometry, defined the material as water, did 'finer' mesh, specified the inlet and outlet, and their corresponding boundary conditions as velocity, where the outlet velocity is half of the inlet velocity since there is one inlet and two outlets with same cros-sectional areas.

I did all of this in Creeping Flow module... Actually this might be problematic since the Reynold's number in the system is 1.27 ( channel cros-section : 130x500 um , and inlet velocity : 7.6 mm/s )


When I tried solve it for Stationary Flow, I couldn't get a convergence after waiting 36 hours ( Here is a screenshoot that i took just befor cancelling the computation : postimg.org/image/48uqj45wn/ )

Are there anyone who have modelled Dean Flow before?

At what point I'm making a wrong thing?

Any advice or suggestion will be appreciated :)

Thanks in advance
3 Replies Last Post Oct 6, 2015, 5:47 a.m. EDT
Md Usuf
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago Oct 2, 2015, 5:36 a.m. EDT
Hi Utku,

I also modelled the similar spiral channel. I selected user defined model and could able to simulate the laminar flow physics and do not get convergence problem, Also I use particle tracing module to see the effect of dean flow on the particle. But unfortunately, I m not able to see the effect. I don t know what had gone wrong with the design. I believe the design is Ok. I m bother that, any equations for dean velocity needs to incorporated somewhere in the initial BC's?
Looking for somebody's help.

Thanks

Yousuf
Hi Utku, I also modelled the similar spiral channel. I selected user defined model and could able to simulate the laminar flow physics and do not get convergence problem, Also I use particle tracing module to see the effect of dean flow on the particle. But unfortunately, I m not able to see the effect. I don t know what had gone wrong with the design. I believe the design is Ok. I m bother that, any equations for dean velocity needs to incorporated somewhere in the initial BC's? Looking for somebody's help. Thanks Yousuf
Utku Sönmez
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago Oct 2, 2015, 10:48 a.m. EDT
Hi Yousuf, I think I found the point at which I made mistake. As you told, the problem was about the boundary conditions. I had given a outlet velocity boundary condition together with the inlet velocity boundary condition. When I change the velocity boundary condition to 'zero pressure' boundary condition, the solution converged.

Now I'm dealing with the particle traction module :)

Utku.
Hi Yousuf, I think I found the point at which I made mistake. As you told, the problem was about the boundary conditions. I had given a outlet velocity boundary condition together with the inlet velocity boundary condition. When I change the velocity boundary condition to 'zero pressure' boundary condition, the solution converged. Now I'm dealing with the particle traction module :) Utku.
Md Usuf
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago Oct 6, 2015, 5:47 a.m. EDT
Have you got an idea where to incorporate inertial force and dean force equations in particle tracing module, so that, drag force along with this two forces results in particle separation.

Thanks
Yousuf
Have you got an idea where to incorporate inertial force and dean force equations in particle tracing module, so that, drag force along with this two forces results in particle separation. Thanks Yousuf

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