SimScale CAE Forum

The simulation of flow in micro channels


#1

Hello,

I am trying to run a simulation for flow in micro channels. The meshed part does not look like the cad drawing. And I can not choose the faces I want.

Please find the projects I created below,

https://www.simscale.com/projects/akoksal/micro_channeled_chip/

https://www.simscale.com/projects/akoksal/microchannelflow_1/

The first project above is a the real situation, micro channels in between two plates, and the second is what the channels inside the planes look like.

Your advice would be appreciated,

Regards,

Akin


#2

Ooh, I am also interested in these kind of simulations. Looking at your geometry I can tell that messhing might be tough. Usually meshes do not like high aspect ratio. Also, I am not sure but it seems like your geometry is showing the volume of the solids but not the fluid’s volume? I recommend you to at first just have the volume of the fluid (which can be created with a Boolean operation. This will make meshing better and it is what you need for an internal CFD simulation. So pretty much, your second project. Now, it seems like there are some issues with your geometry, I would check it and make sure that all faces are connected and no weird curvatures on them, check the edges and remove hard edges and unnecessarily small ones (sometimes you just need to erase the small edge and extend the longer co-linear edge it was attached to.) Also make sure that the volume is airtight, meaning there are no gaps or missing faces. Your software might have an evaluation tool for all these issues. My second suggestion is that you go with hexa dominant parametric mesh since it allows u more control on your mesh (it seems like the mesh on the second project could not go as fine as needed).


#3

Hello,
I scaled up the size in the drawings and reduced the complexity, afterwards it seemed to make proper meshes and even simulate. Now for the ‘thinnermesh’ file, i would like to postprocess the results. But unfortunately, nothing can be ssen on the screen. I change directions, zoom in and out but neither option seem to give a visualization. Could you please advise?

https://www.simscale.com/projects/akoksal/thinnermesh/

Thanks,
Akin


#4

@akoksal, adding a slice filter will help you to see the flow inside. Is this what you are looking for?


#5

Yes, Thank you AnnaFless, I guess the center of the geometry was not where I expected. Regards, Akin


#6

The streamtraces would not show, too.MAybe you could recommend something? Thanks, Akin


#7

Hi @akoksal,

Streamlines can be generated for Run 2 - Solution field, the point source has to be exactly specified to visualize the flow. You can use the following points for reference.
P1- (-0.5, -0.5054, -0.0975), Radius - 0.005
P2- (-0.5, 0.5054, -0.0975), Radius - 0.005
P3- (0, 0, -0.0975), Radius - 0.005

A suggestion for this simulation setup - velocity conditions for both inlet and outlet is kind of an ill posed problem. You can expect numerical errors during the calculation and especially for incompressible flow the solver might crash if the continuity is not satisfied. Please consider giving a pressure outlet condition to avoid imbalances.

Regards,
Sam


#8

Thank you very much. I will surely take into consideration your recommendations. And I will try with even smaller scales.


#9

Was just reminded of this post from @dheiny, thought it might help in this case :