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

Modelling turbulator tape on airfoil

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 16, 2011, 14:30
Default Modelling turbulator tape on airfoil
  #1
New Member
 
Join Date: Jan 2011
Posts: 2
Rep Power: 0
focus is on a distinguished road
Dear All,
I am going to evaluate the effect and position of "Turbulator-tape" on an FX67-K170 aifoil(this is a tipical glider airfoil, used late 70s on many gliders, like LS3, Nimbus, LAK, Glassfugel, etc..). The main reason attaching Turbulator-tapes on airfoils to prevent flow separation, controlling the boundary layer. Is is commonly used on modern glider aifoils, but it was unknown at that time when the FX67-K150 and K170 aifoils were designed. The are two types: "Zig-Zag or 3D" with 0.5-0.8 mm height and "Dimple", which is a simple tape with small, about 1mm height bumps. You can see here: http://www.streifly.de/shop%20baender-e.htm how the zig-zag tape looks like. I am attaching two picturs for better understanding.I could use Ansys13.
Thanks in advance any info, help.
Attached Images
File Type: jpg LS3_noppelband.jpg (86.7 KB, 56 views)
File Type: jpg LS4_zigzag.jpg (85.8 KB, 41 views)
focus is offline   Reply With Quote

Old   January 16, 2011, 17:14
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,692
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
I am well aware of turbulators. But what are you trying to do? Assess the lift/drag on the airfoil with the turbulators in different positions around the wing? This will be tricky to model as correctly modelling the turbulators will be difficult to get accurate. There are a number of approaches (listed in approximately easiest but least accurate to hardest and most accurate):

1) Use a turbulance transition model and fix the turbulence transition point to the turbulator.
2) Use a turbulence transition model and use a rough surface at the turbulator to maybe trigger turbulence.
3) Use a turbulence transition model and use a source term to add the correct amount of turbulence intermittency at the turbulator to maybe trigger turbulence.
4) Do a full DNS model, including the turbulator roughness.
ghorrocks is offline   Reply With Quote

Old   January 17, 2011, 02:43
Default Modelling turbulator tape on airfoil
  #3
New Member
 
Join Date: Jan 2011
Posts: 2
Rep Power: 0
focus is on a distinguished road
Thanks Glenn for your answer. Yes I am going to assess the lift/drag on the airfoil with the turbulators in different positions, because I have a glider with that airfoil. What does it mean "full DNS model"?
focus is offline   Reply With Quote

Old   January 17, 2011, 16:43
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,692
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
This will be difficult to model accurately, you are going to need some very good experimental data to get the turbulence triggering happening correctly.

Try google for a definition of DNS. I don't want to scare you
ghorrocks is offline   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
airfoil trailing edge modelling in gambit morteza08 Main CFD Forum 3 June 4, 2010 13:36
Airfoil Ice Accretion Modelling Using Fluent Virk FLUENT 0 July 27, 2009 06:48
Modelling flow separation over airfoil at stall Kelvin Main CFD Forum 4 June 6, 2007 17:54
Modelling flow over airfoil at near stall angle Kelvin FLUENT 5 June 6, 2007 02:00
modelling an airfoil Chetan Kadakia FLUENT 10 December 3, 2001 16:17


All times are GMT -4. The time now is 11:28.