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Old   March 10, 2012, 12:58
Default Oscillatory inlet velocity profile
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Dear All,

I'm trying to validate openFoam to simulate oscillating flow fields.
I want to simulate 2D channel flow with oscillating inlet velocity. I'm using icoFoam as solver, the velocity inlet bc that I want to imposed is of the form u(t)=a+b*sin(2pi*f*t), where a, b are constant, t is time and the f is frequency of oscillation. Moreover I've imposed 0 pressure at the outlet and no-slip condition at the wall.
I'v tried to used the oscillatingFixedValue as boundary condition type for inlet velocity. The solution doesn't seem to converge. Have you got any suggestion? Has somebody used oscillatingFixedValue bc before?
Is it proper to describe my inlet condition?

Thanks in advance.
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Old   March 10, 2012, 15:20
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Hi!

you say your solution doesnt seem to converve... but you're doing a transient solution... you should operate with low residuals, but it won't converge to say.. e-5, e-7.... at most i guess 1e-2 maybe 1e-3, unless it's a very shy transient case..
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Old   April 3, 2012, 00:25
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Hi Alinve,

Glad to know someone doing similar research. I am thinking the inlet boundary condition for pressure is also essential for the oscillating flow simulation. Be noted that the velocity at out BC changes with time. Can you specify those BCs that were imposed in your case?

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Originally Posted by alinve View Post
Dear All,

I'm trying to validate openFoam to simulate oscillating flow fields.
I want to simulate 2D channel flow with oscillating inlet velocity. I'm using icoFoam as solver, the velocity inlet bc that I want to imposed is of the form u(t)=a+b*sin(2pi*f*t), where a, b are constant, t is time and the f is frequency of oscillation. Moreover I've imposed 0 pressure at the outlet and no-slip condition at the wall.
I'v tried to used the oscillatingFixedValue as boundary condition type for inlet velocity. The solution doesn't seem to converge. Have you got any suggestion? Has somebody used oscillatingFixedValue bc before?
Is it proper to describe my inlet condition?

Thanks in advance.
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