CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Negative pressure in incompressible steady-state model

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 27, 2019, 09:19
Question Negative pressure in incompressible steady-state model
  #1
New Member
 
Estelle
Join Date: Mar 2019
Posts: 10
Rep Power: 4
Estelle13 is on a distinguished road
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 05:07.
Estelle13 is offline   Reply With Quote

Reply

Tags
incompressible, negative, newtonian fluid, pressure, steady-state

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Droplet is just getting disaaper after Steady state VOF model raushan kumar Fluent Multiphase 0 May 20, 2019 09:32
mass flow in is not equal to mass flow out saii CFX 12 March 19, 2018 05:21
Simulation of a single bubble with a VOF-method Suzzn CFX 21 January 29, 2018 00:58
static vs. total pressure auf dem feld FLUENT 17 February 26, 2016 13:04
An error has occurred in cfx5solve: volo87 CFX 5 June 14, 2013 17:44


All times are GMT -4. The time now is 21:32.