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

magnus effect

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 3, 2002, 11:01
Default magnus effect
  #1
benoit
Guest
 
Posts: n/a
Hi, I am a student and I am doing a project about the magnus effect. I use FLUENT to do it. I have several problems and perhaps you can give me some advices :

(1) I have many convergence problems, I have to decrease the under-relaxation factor (moment and energy) and I can increase it at the end of the calculation (segregated, steady).

(2) At low speed ratio, the flow seems to be unsteady .?

(3) With FLUENT, there is no negative magnus effect at low speed ratio. I don't knnow if it is normal ? ( FLUENT have no model for transition in boundary layer ?)

(4) I have experimental results (NACA 1925), and my results seems to be three time more. I havn't all the values of the parameters of the experimentation : mach, pressure ... exemple of my computation results:

rho=1.225 , P=101325 Pa, V=15 m/s, smooth

ratio=1 -> Cl=2.7 (realizeable et two-layer)

ratio=0.5 -> Cl=1.2

many thanks

benoit

  Reply With Quote

Old   June 4, 2002, 04:00
Default Re: magnus effect
  #2
Laika
Guest
 
Posts: n/a
Hello Benoit,

can you tell a bit more about your case please; it's interesting.

Is it 2D? How do you define your speed ratio ( u/v I assume)?

With the realizable k-eps-model it's possible you'r picking up vortex shedding. What results do you have with the Spalart-Almares model?

Have you adjusted the reference values to calculate the Cl? Do you obtain reasonable results for the drag-force?

You are using moving-wall I assume.

greetings,

Laika, still orbiting
  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
How to create rotary domain for Magnus effect vovogoal CFX 0 March 22, 2009 16:22
VOF and strong surface tension effect phsieh2005 Main CFD Forum 1 August 30, 2005 06:56
magnus effect jackie FLUENT 1 December 19, 2004 18:57
Iclude particle diameter effect in wall? yueroo FLUENT 0 April 14, 2001 03:56
Magnus Effect Model Dahvid Brown FLUENT 1 February 24, 2000 10:59


All times are GMT -4. The time now is 02:23.