|
[Sponsors] |
discontinous pressure at the corners of a nozzle simulation (simpleFoam) |
![]() |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
![]() |
![]() |
#1 |
New Member
Sven
Join Date: Feb 2010
Posts: 4
Rep Power: 16 ![]() |
I had some problems with a much more complicated simulation so I started simplifying my mesh and setup until I ended up at a steady laminar incompressible flow...
Anyway this doesn't work and i am probably forgetting something stupid... but i am trying around for hours now... So any help is appreciated! ![]() So my problem is that i get extreme pressure values at the corners of my inlet... The velocity field looks okish for something with such a messed up pressure distribution... So to my current setup: solver: simpleFoam RASProperites RASModel laminar; turbulence off; transportProperties rho 0.524; nu 62.53; p internalField uniform 193368; wall zeroGradient; outlet fixedValue 193368; inlet fixedValue 193368; U internalField uniform (0 0 0) wall fixedValue (0 0 0) outlet zeroGradient inlet flowRateInletVelocity flowrate 0.615 value uniform (0 0 0) |
|
![]() |
![]() |
![]() |
![]() |
#3 |
New Member
Sven
Join Date: Feb 2010
Posts: 4
Rep Power: 16 ![]() |
i tried that... it's divergent...
and i know why ![]() because of the geometry the fd becomes unstable and the system is generating energy... so to lose energy again the system is going into a negative pressure to get to the energy state that is enforced by the outlet bcs... the velocity is not affected as much because of mass conservation... |
|
![]() |
![]() |
![]() |
![]() |
#4 |
New Member
Sven
Join Date: Feb 2010
Posts: 4
Rep Power: 16 ![]() |
oh well you are obviously right...
![]() there needs to be some pressure increase between the inlet and the outlet ![]() changed that to a fixed pressure after the convergence problems... which were caused by the discontinuies and the zero gradient pressure bc at the inlet, which lets the pressure of the inlet approach infinity... I switched to directMapped BCs, changed the mesh and the inlet to zero gradient pressure ![]() |
|
![]() |
![]() |
![]() |
Tags |
nozzle, simplefoam |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Pressure calc for M6 simulation | steve1 | Main CFD Forum | 0 | June 19, 2010 19:14 |
compressible flow in a counterflow nozzle | d.vamsidhar | FLUENT | 0 | November 24, 2005 01:45 |
Total pressure in a laval nozzle | Sohail Ahmed | FLUENT | 0 | May 19, 2004 05:28 |
stagnation pressure in transient flow simulation | K.S.Ravichandran | Main CFD Forum | 2 | September 5, 2000 00:34 |
Hydrostatic pressure in 2-phase flow modeling (long) | DS & HB | Main CFD Forum | 0 | January 8, 2000 15:00 |