CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Dynamic Ground Effect Simulations

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

Like Tree1Likes
  • 1 Post By me3840

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 16, 2020, 07:16
Default Dynamic Ground Effect Simulations
  #1
New Member
 
James Permain
Join Date: Feb 2020
Posts: 5
Rep Power: 6
JamesPermain is on a distinguished road
I am hoping someone can help me with a possible way I may be able to define the position of my ground wall boundary relative to my 2D moving airfoil for which I want to simulate dynamic ground effect.

I am going to be running dynamic simulations for a NACA4412 airfoil under the influence of ground effect. I will be moving my airfoil in two ways during my simulations:

1) A constant pitch angle and constant sink rate approach to the ground
2) A varying pitch angle rotation at a given height above the ground

I need to define my airfoil's instantaneous height above the ground as the distance between the ground and its closest point to the ground. For angles above roughly 1 degree this is always the trailing edge, but for lower pitch angles this point of closest approach varies with pitch.

I therefore need a way to extract the minimum distance from my airfoil's geometry to the ground wall so that I can match values of lift and pitching moment to given heights.

If there was also a way to create a field function that I could plot/export that would be great, and if I could also use the field function as an input into the origin of my background (and thus wall boundary) I would be able to manually define heights for these tricky pitch angles based off the airfoil's geometry.

Any ideas on how I can do this are much appreciated! Please ask for any clarification if this post is not clear; it is my first one on this forum!
JamesPermain is offline   Reply With Quote

Old   March 19, 2020, 15:17
Default
  #2
Senior Member
 
Join Date: Nov 2010
Location: USA
Posts: 1,232
Rep Power: 24
me3840 is on a distinguished road
Is this a transient simulation? If so you can easily define a coordinate system at the non-moving component and then evaluate the minimum of position (using a report) on the airfoil boundary. Recording that as a monitor will give you a plot of time vs height.
Steklo_Plastik likes this.
me3840 is offline   Reply With Quote

Old   March 20, 2020, 10:31
Default
  #3
Member
 
Chris
Join Date: Dec 2018
Posts: 36
Rep Power: 7
Chris2337 is on a distinguished road
I would also make the ground boundary a symmetry plane so it doesnt grow a boundary layer but does act like the ground.
Chris2337 is offline   Reply With Quote

Old   March 21, 2020, 09:00
Default
  #4
New Member
 
James Permain
Join Date: Feb 2020
Posts: 5
Rep Power: 6
JamesPermain is on a distinguished road
Quote:
Originally Posted by me3840 View Post
Is this a transient simulation? If so you can easily define a coordinate system at the non-moving component and then evaluate the minimum of position (using a report) on the airfoil boundary. Recording that as a monitor will give you a plot of time vs height.
Yes these are transient simulations. This is exactly what I was looking for. I have implemented this and it's working just right. Thank you for your help.
JamesPermain is offline   Reply With Quote

Old   March 21, 2020, 09:02
Default
  #5
New Member
 
James Permain
Join Date: Feb 2020
Posts: 5
Rep Power: 6
JamesPermain is on a distinguished road
Thank you for your suggestion Chris. I have set the wall boundary to a slip condition under the shear stress condition so this should prevent the formation of a boundary layer anyway.
JamesPermain is offline   Reply With Quote

Reply

Tags
field function, geometry, ground effect

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
Ground Effect hk.narahari SU2 4 November 12, 2021 07:25
[ANSYS Meshing] Divide entire ground into sub sections for moving ground for vehicle aerodynamics CFD johny_walker ANSYS Meshing & Geometry 0 February 24, 2020 10:42
Ground effect on wing hk.narahari Main CFD Forum 1 September 13, 2019 04:52
[ICEM] meshing airfoil in ground effect cfd_peter ANSYS Meshing & Geometry 12 March 14, 2017 18:30
Ground effect in wings varies with turbulence models ?? redordead FLUENT 0 October 8, 2016 16:50


All times are GMT -4. The time now is 08:26.