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July 8, 2013, 09:53 |
negative pressure
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#1 |
Member
Sa.Baraty
Join Date: Apr 2013
Location: Iran
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Hi all.
I simulated one heat sink that has some microchannels. and boundary conditions: 1 velocity inlet for fluid inlet 2 pressure outlet for fluid outlet. and two thermal boundary for heat sink. when converge my RUN pressure @ out let become negative.!???? please help me.
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July 10, 2013, 03:43 |
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#2 |
Senior Member
Philipp
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You mean the pressure at the pressure outlet becomes negative?
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July 10, 2013, 15:28 |
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#3 |
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Sa.Baraty
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Location: Iran
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yes.pressure @ outlet becomes negative
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July 11, 2013, 03:03 |
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#4 |
Senior Member
Philipp
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But this doesn't make any sense to me. If you set the outlet pressure to some value (as a BC), how can this value change during your simulation?
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July 11, 2013, 04:19 |
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#6 |
Senior Member
Philipp
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Yes, but he says "converge" in his initial post. I doubt he will get convergence in such a case.
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July 12, 2013, 02:14 |
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#7 |
Member
Sa.Baraty
Join Date: Apr 2013
Location: Iran
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yes my RUN become converge. But pressure value @ outlet is negative.for example pressure @ inlet B.C be 5687 Pa. and @ Outlet B.C be -879 Pa.
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July 12, 2013, 03:33 |
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#8 |
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Alex
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Please post images of the velocity and pressure contours and of the residuals.
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July 12, 2013, 04:37 |
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#9 |
Senior Member
Philipp
Join Date: Jun 2011
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Generally, negative pressures are no problem, since your pressures are gauge pressures. There is a large positive offset of 1e5 Pa to them...
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