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Drag Force on a sand particle

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Hi,
I’m currently simulating a sand particle flowing within oil in a pipe. I’m required to find the drag force acting on the sand particle during its flow.

With the laminar flow:
To find Total Force: I did a surface integration over the sand particle by choosing it’s boundaries and then for the expression I chose total stress (spf.T_stressx) but this gave me very small values.

I also tried using particle evaluation from the derived values and inserting the drag force, x component, from the particle tracing expressions but it just gave me zero.

Is it best to model only the fluid in the pipe then use the particle tracing to find forces on the sand particle or do I draw the particle as a sphere within the pipe and compute the study? I did both but I can’t seem to work it out.

3 Replies Last Post Aug 7, 2014, 10:54 a.m. EDT
Jeff Hiller COMSOL Employee

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Posted: 1 decade ago Aug 6, 2014, 5:29 p.m. EDT
You may like this link: www.comsol.com/model/terminal-falling-velocity-of-a-sand-grain-983
Jeff
You may like this link: http://www.comsol.com/model/terminal-falling-velocity-of-a-sand-grain-983 Jeff

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Posted: 1 decade ago Aug 7, 2014, 9:04 a.m. EDT
Thanks a lot Jeff!
Do you have any idea what kind of operation or expression I could use to get the drag force on the sand in a turbulent flow?
Thanks a lot Jeff! Do you have any idea what kind of operation or expression I could use to get the drag force on the sand in a turbulent flow?

Jeff Hiller COMSOL Employee

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Posted: 1 decade ago Aug 7, 2014, 10:54 a.m. EDT
Please contact COMSOL's technical support to request assistance if your license is eligible for that service: www.comsol.com/support/
Best,
Jeff
Please contact COMSOL's technical support to request assistance if your license is eligible for that service: www.comsol.com/support/ Best, Jeff

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