Negative pressure in incompressible steady-state model
 

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 :confused: