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May 8, 2012 4:50am UTC

shear stress in microchannel

Hello,

I am clueless as to how to start the post-process data analysis to get the spatial distribution of shear stress of a micro channel. I have read the few discussion threads but it involves exporting the slice 3D plot of the velocity and then do the calculation of shear stress in Matlab. I would appreciated it if someone can either tell me (a) what Matlab code or equation you used to solve for shear stress from the velocity profile slice or (b) a way to get Comsol to compute shear stress for me and graph it (a much easier way for a newbie like me).

Thank you so much!

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May 8, 2012 4:28pm UTC in response to Ivar Kjelberg

Re: shear stress in microchannel

Correct me if I am wrong, the direction of my flow velocity is in the y-axis and if I want to calculate the shear stress for an xy plane slice along a z-axis coordinate, then I input the expression "spf.mu*(vx+uy)" with spf.mu is the dynamic viscosity to give shear stress in Pa?

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May 8, 2012 9:52pm UTC in response to Ivar Kjelberg

Re: shear stress in microchannel

i don't quite understand what you mean by the previous statement because when I enter that tensor variable expression I get the same results as before.

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June 6, 2012 4:47am UTC in response to Cindy Duong

Re: shear stress in microchannel

Hi

my comment was just to remind you about all the predefined internal variables of COMSOL, unfortunately I do not know of any exhaustive list, but you can find them in the pull down menus of the Derived Variables, (or with the CNTRL Space) and in the equation view nodes

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Good luck
Ivar

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