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

Internal flow simulation boundary conditions

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 2, 2007, 02:12
Default Internal flow simulation boundary conditions
  #1
Kishore
Guest
 
Posts: n/a
hi, need ur suggestions in this prblm Problem description: it is a internal flow simulation through a duct connected to a chamber which has 2 outlets(identical area).the flow is a velocity at inlet is 42 m/s and static pressure is 1.2 bar with T= 298 k. outlet conditions are not known. pressure drop from inlet to outlets is not known.

method i tried for simulating and getting conditions at outlet is as follows : i gave velocity inlet and 2 outflows and computed the static pressure using area weighted average option for the two outlets. then in the second simulation i gave this static pressure at outlet and 1.2 bar at inlet with pressure inlet and pressure outlet boundary conditions. my query: is this simulation physically correct to determine the outlet conditions? because when initializing before iterating , the inlet velocity which fluent computes and gives for initialization is nearly 3 times (150 m/s). kindly help in this...
  Reply With Quote

Old   July 10, 2007, 11:42
Default Initialization with UDF
  #2
Chx
Guest
 
Posts: n/a
Using FLUENT, I am trying to generate a regular wave in a 2d domain by specifying a transient velocity profile at my inlet. The top and end of my domain are pressure outlets with atmospheric pressure and hydrostatic pressure specified for both boundaries respectively. Gravity is acting in the negetive y direction and based on my UDF, I expect maximum velocities of 1.7m/s but when initializing before iterating , the inlet velocity which fluent computes and gives for initialization is nearly 17 times (28 m/s). I have looked at and had many guys look at my UDF over and over again and can't find anything wrong with it. Any body has an idea where the problem could be?
  Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
non reflective boundary conditions for incompresible flow Pascal_doran OpenFOAM Programming & Development 15 August 7, 2014 05:55
Periodic boundary conditions in 3D Eulerian granular flow simulations dsm FLUENT 4 March 2, 2012 19:04
Boundary conditions low Mach number flow lost.identity Main CFD Forum 0 November 28, 2010 04:44
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 04:05
Boundary Conditions Jan Ramboer Main CFD Forum 11 August 16, 1999 08:59


All times are GMT -4. The time now is 23:12.