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Modelling a swirling gas

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Hi,

In my CFD model I receive gas from a process through a pipe. The gas in the pipe is swirling, i.e. besides the axial velocity vector there is a tangential velocity vector. Does anybody know how I can set up the boundary inlet conditions so that I can make the gas swirl?

Many thanks,
Calle

3 Replies Last Post 15.02.2015, 00:53 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 24.07.2010, 03:38 GMT-4
Hi

cant you define a cylindrical coordinate V4 (r,phy,a) and use that to define your initial conditions ?

--
Good luck
Ivar
Hi cant you define a cylindrical coordinate V4 (r,phy,a) and use that to define your initial conditions ? -- Good luck Ivar

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Posted: 1 decade ago 24.07.2010, 07:45 GMT-4
Hi,

Thanks for your reply. I would prefer to finish this model in V35 as it is already well under way. Also, I am not sure how to cope with that the downstream geometry is not axis symmetric. The model is truly 3D.

Some years ago I worked with V32. It had a function "s" (s1, s2 and s3 in 3D) which was very useful for creating assymetric and time dependant functions on the inlet flow. However the s function does not work on V35. Is there a substitute?

Thanks,
Calle
Hi, Thanks for your reply. I would prefer to finish this model in V35 as it is already well under way. Also, I am not sure how to cope with that the downstream geometry is not axis symmetric. The model is truly 3D. Some years ago I worked with V32. It had a function "s" (s1, s2 and s3 in 3D) which was very useful for creating assymetric and time dependant functions on the inlet flow. However the s function does not work on V35. Is there a substitute? Thanks, Calle

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Posted: 9 years ago 15.02.2015, 00:53 GMT-5
WHY cant you try swirl dominant flow and add a swirl factor of 0.5. model k-epsilon
WHY cant you try swirl dominant flow and add a swirl factor of 0.5. model k-epsilon

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