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

2D Flow over cylinder, low lift/drag coefficients

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 3, 2009, 10:00
Default 2D Flow over cylinder, low lift/drag coefficients
  #1
New Member
 
Steve
Join Date: Aug 2009
Posts: 1
Rep Power: 0
olives03 is on a distinguished road
Hello all,

I am currently attempting to determine the lift and drag coefficients for airflow over a single cylinder in both laminar/turbulent flow scenarios using FLUENT.

My issue is that the drag and lift coefficients are much lower than expected, with most analysis giving lower Cd and Cl values (currently working on the laminar case - Re = 100, haven't started on the turbulent yet)

Mesh should not be an issue, I am currently troubleshooting by using a mesh from the previous year that was known to be successful.
I am scaling the grid down from metres to inches, yet in the reference values remain as 'Area' and 'Length' = 1m

I get the feeling that I need to change one or both of these to .0254 to account for my reduction in grid size by .0254 - is this correct, or are there other factors that could cause these low Cd & Cl values?

Any help would be greatly appreciated - I've got a lot on at uni and want to get this project/thesis out of the way.


Regards,

Steve
olives03 is offline   Reply With Quote

Old   February 11, 2011, 19:05
Default
  #2
Senior Member
 
Ugly Kid Joe
Join Date: Aug 2010
Posts: 193
Rep Power: 15
vmlxb6 is on a distinguished road
Hey,

I am also simulating a 2-D flow over a stationary cylinder to determine the Cl and Cd over the cylinder. My question is in the lift coeff formula i.e Cl=F/(0.5*density*U^2 *Area), the area is the projected area i.e length*diameter or the surface area (2*pi*radius*length) ???

Also what values should I put for Depth, Enthalpy, Ratio of Sp. heat in the reference values ???

Is the depth same as diameter of the cylinder ???
vmlxb6 is offline   Reply With Quote

Reply

Tags
cylinder, low drag

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
benchmark: flow over a circular cylinder goodegg Main CFD Forum 12 January 22, 2013 12:47
flow around a cylinder pXYZ Main CFD Forum 14 July 25, 2011 11:05
Anybody knows smth abt the flow around a cylinder? Wenxuan Main CFD Forum 3 March 20, 2007 17:19
Flow over a cylinder Anna Main CFD Forum 9 March 24, 2006 15:32
axial flow around a cylinder -heat transfer model? Ralf Schmidt Main CFD Forum 1 March 21, 2006 09:54


All times are GMT -4. The time now is 05:50.