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

Back flow problem in gas cyclone

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 31, 2012, 05:27
Default Back flow problem in gas cyclone
  #1
New Member
 
Join Date: Oct 2010
Posts: 20
Rep Power: 16
lakhi is on a distinguished road
Hi.
I'm working on Stairmand high efficiency cyclone model. I have a problem that I am getting back flow in the central region, from vortex finder. I am using unsteady RSM model with standard wall function (I have also tried the enhanced wall treatment option); with velocity inlet for inlet, outflow for flow outlet, and walls for dustbin and other walls as the Boundary Conditions. For pressure-velocity coupling I am using SIMPLE (I have also used SIMPLEC). For others it is PRESTO, QUICK, 2nd order, 2nd order. For RSM it is 1st order. I'm using Fluent v14, and I have meshed using GAMBIT as well as ICEM CFD, but I am getting the same results. The tangential velocity profile is fine. My problem is the back flow at the outlet (vortex finder). I am still struggling with single phase flow (no Discrete Phase Model introduced yet).

Can anybody please help me to get rid out of it. I have also tried to extended the outlet (vortex finder) length upto 5 times the diameter so that the flow is fully developed and there is no back flow, but still the results are same.

Do I need to work on some coding (in the form of .udf) to eliminate this?

I am stuck to this problem since last 3 months. Looking forward for your positive response.
Attached Images
File Type: jpg Velocity Vector.jpg (94.8 KB, 32 views)
File Type: jpg Axial Velocity contour.jpg (76.5 KB, 38 views)
lakhi is offline   Reply With Quote

Reply


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
Boundary condition problem for open channel flow Andy CFX 9 June 11, 2016 08:20
Multiphase phase (gas-solid) flow using Eulerian-Granular medel ( divergence problem) jessie FLUENT 3 May 29, 2014 12:05
gas solid flow problem validation pandaba FLUENT 0 October 27, 2010 07:05
source term in a gas mixture problem Kevin Siemens 0 March 27, 2008 06:55
cyclone problem Jichun FLUENT 4 May 16, 2002 05:43


All times are GMT -4. The time now is 00:57.