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fluid flow: high velocity around pressure point constraint?

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Hi,

I am currently simulating a fluid flow model (laminar flow) and trying to analyze the flow field within an 2D axisymmetrical truncated ellipse.

I applied a pulsatile inlet flow rate and pressure constraint point (add from laminar flow>points>pressure point constraint) in the model (as shown in attached picture: pressure constraint point.tif).

By examining the result, it was found that high velocity magnitude existed around the pressure point constraint (as shown in attached picture: high velocity problem.tif). However I assumed the velocity at this site should not be this high but similar with surrounding regions (in blue colour).

Could anyone tell me why/what cause to this problem happening?

Looking forward for your help and reply. Thanks a lot!


1 Reply Last Post Jan 22, 2012, 11:47 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jan 22, 2012, 11:47 a.m. EST
Hi

it's not easy to understand, I assume the inlet is the horizontal cut line on top, where you have a p=0 pressure point. But what about the outlet ?

If none, I assume its not tat wrong, as your 2D-axi will give some central flow and pressure increase (as the flow area is larger here) and you will get an outflow (through the inflow boundary around the lowest pressure point constrained to p=0

But again, I might be wrong as I might not have correctly understood all your BC's there


--
Good luck
Ivar
Hi it's not easy to understand, I assume the inlet is the horizontal cut line on top, where you have a p=0 pressure point. But what about the outlet ? If none, I assume its not tat wrong, as your 2D-axi will give some central flow and pressure increase (as the flow area is larger here) and you will get an outflow (through the inflow boundary around the lowest pressure point constrained to p=0 But again, I might be wrong as I might not have correctly understood all your BC's there -- Good luck Ivar

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