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

Turbulent steady flow around a circular cylinder

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 23, 2003, 19:40
Default Turbulent steady flow around a circular cylinder
  #1
Mirek Kabacinski
Guest
 
Posts: n/a
Hello Fluent Users, I have some problems with computation of turbulent incompressible steady air flow around circular cylinder (2D and 3D) using k-epsilon model at Reynolds number from 1E+2 to 1E+5 (subcritical). My problem is in a pressure distribution on cylinder surface. In the front side of the cylinder everything is OK according to literature datas (and my own experiments). But problem is from about angle = 40 degrees to 180 (most of all). This pressure distribution on cylinder surface is typical for SUPERCRITICAL FLOWS but Re number of the flow indicates that it is subcritical! I read in literature that Re subcritical is below 1.86E+5 and supercritical is under 6.7E+5. In my experiments the pipe has diameter of 150mm and cylinder has diameter of 12mm (this is an impact flowmeter). At v=30m/s I obtained in the front of cylinder (in stagnation point) p stat = 616Pa (596Pa in Fluent) but at the back side of cylinder in experiment it was p stat = -872Pa (-155Pa in Fluent!OVER 400% ERROR!) My question is: How to force Fluent to make a proper calculations? My mesh on cylinder has intervals equals 0.27mm, I used inflow as velocity-inlet B.C., walls of pipeline and of cylinder as wall B.C. and outflow as outflow B.C., and convergence in case of 3D simulations on level of 0.0001, computation domain has about 2mln elements. Now, I'm trying to get correct answer in case of 2-D infinite turbulent steady incompressible flow around circular cylinder and when it'll be successful I'll try to solve my problem in 3-D case. Can anybody help me with my odd problem? Thanks anybody in advance for help.
  Reply With Quote

Reply

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
asking about wake in Inviscid flow in cylinder circular teguhtf FLUENT 0 April 23, 2011 01:14
Turbulent flow through hexagonal circular pipe yogesh@cfd Main CFD Forum 0 November 10, 2010 00:10
Appropriate model for turbulent, steady state pipe elbow flow milos OpenFOAM Running, Solving & CFD 4 July 9, 2009 03:24
Steady Turbulent flow prem FLUENT 2 March 14, 2006 12:58
Modeling flow acros circular cylinder Zhihua Main CFD Forum 3 April 20, 2004 12:16


All times are GMT -4. The time now is 05:09.