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

How to apply Neumann Boundary condition in Fluent

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

Like Tree1Likes
  • 1 Post By Luttappy

Reply
 
LinkBack Thread Tools Display Modes
Old   September 2, 2016, 16:26
Thumbs up How to apply Neumann Boundary condition in Fluent
  #1
New Member
 
HK
Join Date: Oct 2015
Location: Madras
Posts: 8
Rep Power: 3
Luttappy is on a distinguished road
Dear all

I would like to know how to apply Neumann Boundary condition in ANSYS Fluent for zero normal derivative condition at outlet of a channel.

Do we need to write UDF for that or we can apply existing boundary condition in fluent

Thanks in advance for any help or comment.
nikos_ likes this.
Luttappy is offline   Reply With Quote

Old   May 24, 2017, 14:50
Default Use of Outflow boundary condition
  #2
New Member
 
HK
Join Date: Oct 2015
Location: Madras
Posts: 8
Rep Power: 3
Luttappy is on a distinguished road
Finally i found that Outflow boundary condition is suitable for my case.
Fluent manual says that


The boundary conditions used by FLUENT at outflow boundaries are as follows:

A zero diffusion flux for all flow variables.
An overall mass balance correction.
The zero diffusion flux condition applied at outflow cells means that the conditions of the outflow plane are extrapolated from within the domain and have no impact on the upstream flow. The extrapolation procedure used by FLUENT updates the outflow velocity and pressure in a manner that is consistent with a fully-developed flow assumption, as noted below, when there is no area change at the outflow boundary.

The zero diffusion flux condition applied by FLUENT at outflow boundaries is approached physically in fully-developed flows. Fully-developed flows are flows in which the flow velocity profile (and/or profiles of other properties such as temperature) is unchanging in the flow direction.

It is important to note that gradients in the cross-stream direction may exist at an outflow boundary. Only the diffusion fluxes in the direction normal to the exit plane are assumed to be zero.
Luttappy is offline   Reply With Quote

Reply

Tags
ansys fluent, boundary conditions, neumann bcs

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
Error - Solar absorber - Solar Thermal Radiation MichaelK CFX 12 September 1, 2016 05:15
Running UDF with Supercomputer roi247 FLUENT 4 October 15, 2015 13:41
several fields modified by single boundary condition schröder OpenFOAM Programming & Development 3 April 21, 2015 05:09
How to transfer boundary condition from Openfoam to fluent sachinlb OpenFOAM Post-Processing 1 January 6, 2012 02:41
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 16:55


All times are GMT -4. The time now is 11:24.