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Microfluidic Problem: Integration of Total stress=Drag Force?
Posted 2014/09/28 21:54 GMT-4 Computational Fluid Dynamics (CFD), Microfluidics Version 4.2 0 Replies
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I just started to use COMSOL few weeks ago. I model a simple microfluidic channel union with a cylindrical particle on the bottom of the channel. Inlet V is uniform and flow is fully developed in the vicinity of the particle. My goal is: to get hydrodynamic drag applied on the particle. I integrated the total stress in x, y, z direction. But the problem is that it keeps giving negative total stress which makes no sense because the flow is in positive x direction. My questions are:
1. Can I integration total stress in x direction to get drag force? Since it is total stress I assume it include viscous stress and hydrodynamic pressure which give hydrodynamic drag.
2. Why the integration of total stress in x direction is negative? Is it because stress is defined as stresses applied on the fluid?
My file size doesn't allow me to upload. So I just post two images to help to understand.
Thanks
Hello Jianfeng Sun
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