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Negative pressure in incompressible steady-state model

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Old   May 27, 2019, 10:19
Question Negative pressure in incompressible steady-state model
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Estelle
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Hello everyone !



I need some help with negative pressures appearing in my simulation. I am running an incompressible, steady-state case with a Newtonian fluid using simpleFoam in laminar. Umoy = around 50m/s into the narrowest part which length is around 100 micrometers for a 0.00005 kg/m/s viscosity so approximate Re=100.
I know I am using Gauge Pressure but here the problem is that they are huge... (+/- 30bars approximately).


I am modeling a flow through a valve with a pressure BC of 0bar at the outlet and a velocity BC at the inlet, based on the flow rate continuity as I know the flow rate I want to go through my valve.


I can understand that by the geometry and the tough angle, there is a depression but why that much and why in negative? Should not I have more pressure at the inlet in that case?




I put pictures of the place where it happens, the mesh and glyphs.




Please help me
Attached Images
File Type: jpg glyph.jpg (125.0 KB, 10 views)
File Type: jpg mesh*.jpg (191.3 KB, 9 views)
File Type: jpg neg_pressure.jpg (85.1 KB, 9 views)

Last edited by Estelle13; May 28, 2019 at 06:07.
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incompressible, negative, newtonian fluid, pressure, steady-state

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