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

simulation cyclone

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 5, 2002, 02:53
Default simulation cyclone
  #1
wang haigang
Guest
 
Posts: n/a
Hello, everyone,

Currently, I am using FLUENT to solve a cyclone problem (the cyclone is the same as Fraser:"Computational and experimental investigations in a cyclone dust separator", Pros Instn Mech Engrs Vol 211 Part E,1997. The turbulence model i uesed is RSM and RNG k-eps, the inlet velocity is 7.5m/s. But the maximum swirl veloity is only 5~6m/s compared with the experience 13m/s is very small. Could you give me an adivce and tell me why i can't get the correct result.

Best regards

  Reply With Quote

Old   August 5, 2002, 03:48
Default Re: simulation cyclone
  #2
Bart Prast
Guest
 
Posts: n/a
Grid is too coarse?
  Reply With Quote

Old   August 5, 2002, 05:14
Default Re: simulation cyclone
  #3
wang haigang
Guest
 
Posts: n/a
The grid is : about 40 in the r-direction , 40 in the the-direction and 60 in the z-direction. I think the grid is very fine.
  Reply With Quote

Old   August 5, 2002, 06:35
Default Re: simulation cyclone
  #4
jan rusås
Guest
 
Posts: n/a
Just wsome wild guesses, have you checked; -Are you using higher order differencing schemes -Have you checked your Y+ -How do you treat the outlet from the cyclone, what kind out boundary conditions are you using and are they valid
  Reply With Quote

Old   August 5, 2002, 09:00
Default Re: simulation cyclone
  #5
Elteyeb M. Eljack
Guest
 
Posts: n/a
try to change the values for K and eps., in your intial values and boundry conditions. then look for the false time step !
  Reply With Quote

Old   August 5, 2002, 13:01
Default Re: simulation cyclone
  #6
S. S. Mudathir
Guest
 
Posts: n/a
Hi, I am a new CFD user and till now I have not dived to the zoon of running multiphase flow or advanced turbulence models. I am also not FLUENT user. In the partial fulfillment in required for master degree I am making a comparison study between ALGOR FEA and PHOENICS for a simple flow. At the beginning I found that the results were fluctuation and relatively far from reality and experimental results although the problem I was handling is considered as theoretically solvable by means of analytical methods. I tried to change the grid specifications and found the result changing extremely within the grid dimensions. Due to this I ran a computer experiment by changing the grid specification and then plot the results against the grid dimension. The resulting curve gave me a good indication about the best grid dimensions setting. When I used this setting excellent results were obtained. I think you have to check what is the most suitable grid specification for your case and may be you will get good results. Very glad if this modest contribution could help S. S. Mudathir.
  Reply With Quote

Old   August 7, 2002, 06:57
Default Re: simulation cyclone
  #7
Francisco
Guest
 
Posts: n/a
Dear Wang,

In my PhD dissertation, I´ve been doing LES of a hydrocyclone without air core and the results are quite satisfactory. There are some things you should bear in mind though: 1. this flow is anisotropic, and I´m not sure if the RNG k-eps would work fine, 2. normally, higher order schemes are necessary, even if you´re using RSM. I´ve come across papers showing good results for cyclone flow using the RSM and QUICK scheme. By the way, did you get the Rankine vortex for the swirl velocity?

Best regards,

Francisco.

P.S. For a glance at my preliminary results, visit my homepage: www.geocities.com/chicao99br
  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
Suggestions for modelling a cyclone adona058 OpenFOAM Running, Solving & CFD 2 June 17, 2011 14:43
Cyclone Simulation (simpleFoam) erncyc OpenFOAM 4 January 28, 2011 10:40
velocity profile export from a simulation onto another sudhirlv STAR-CCM+ 1 September 12, 2010 18:57
Replacing mesh while running a simulation akultane CFX 1 November 15, 2009 14:46
About multiphase simulation for cyclone separator Sushil Main CFD Forum 0 July 7, 2007 05:45


All times are GMT -4. The time now is 13:56.