CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Simulating a Car with rotating rims

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 8, 2012, 17:08
Default Simulating a Car with rotating rims
  #1
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Hi all;
could anyone give me some tips about how to simulate a car with rotating rims (with spokes) please?
I don't want full detailed instructions, just the basics:
- solver
- mesh requirements
- …

Thank you!
lovecraft22 is offline   Reply With Quote

Old   March 9, 2012, 03:57
Default
  #2
Senior Member
 
akidess's Avatar
 
Anton Kidess
Join Date: May 2009
Location: Delft, Netherlands
Posts: 919
Rep Power: 17
akidess will become famous soon enough
I'd compare the rims to a mixer: You'll need a solver than can handle a dynamic mesh wish a sliding interface. If you google for "Openfoam mixer", which gives you e.g. this.
__________________
*On twitter @akidTwit
*Spend as much time formulating your questions as you expect people to spend on their answer.
*Help define the OpenFOAM stackexchange Q&A site: http://area51.stackexchange.com/prop...oam-technology
akidess is offline   Reply With Quote

Old   March 11, 2012, 14:43
Default
  #3
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Thank you Anton;
I don't know if that's my case… From what I read that's actually a rotating mesh, isnt'it?
I'd probably only need a rotating reference frame or the wheels…

What do you think?
lovecraft22 is offline   Reply With Quote

Old   March 12, 2012, 04:32
Default
  #4
Senior Member
 
akidess's Avatar
 
Anton Kidess
Join Date: May 2009
Location: Delft, Netherlands
Posts: 919
Rep Power: 17
akidess will become famous soon enough
If you want to simulate the car with the rims, then you need a dynamic mesh. If you just want the rims alone, then maybe you can get by with a moving frame of reference.
__________________
*On twitter @akidTwit
*Spend as much time formulating your questions as you expect people to spend on their answer.
*Help define the OpenFOAM stackexchange Q&A site: http://area51.stackexchange.com/prop...oam-technology
akidess is offline   Reply With Quote

Old   March 12, 2012, 05:40
Default
  #5
Senior Member
 
Elvis
Join Date: Mar 2009
Location: Sindelfingen, Germany
Posts: 577
Blog Entries: 5
Rep Power: 13
elvis is on a distinguished road
There is a tool that was made for automotive industry (and so on)
have a look at icon´s demo and you get an idea how these simulations can be performed
http://www.iconcfd.com/en/services/f...o-process-demo

in that demo they use MRF for the wheels
elvis is online now   Reply With Quote

Old   March 12, 2012, 10:10
Default
  #6
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
MRF stands for moving reference frame, is that correct? So they are not moving the mesh but they do have a moving reference frame for the wheels only, right?

It also seems that they have a volume which encloses the rims…what's that for?

Thank you!
lovecraft22 is offline   Reply With Quote

Old   March 12, 2012, 11:10
Default
  #7
Senior Member
 
Elvis
Join Date: Mar 2009
Location: Sindelfingen, Germany
Posts: 577
Blog Entries: 5
Rep Power: 13
elvis is on a distinguished road
multiple reference frames (MRF)

is implemented in OF since version 1.4
elvis is online now   Reply With Quote

Old   March 13, 2012, 18:49
Default
  #8
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
So Elvis, you are basically saying that I use a MRF on a portion of my domain such as a whee and not on the rest of it (such as the body of the car), correct?
How do I choose a part to be subjected to a MRF?

Thank you for your help.
lovecraft22 is offline   Reply With Quote

Old   March 14, 2012, 04:58
Default
  #9
Senior Member
 
Ralph Moolenaar
Join Date: Aug 2010
Location: 's-Hertogenbosch, the Netherlands
Posts: 120
Rep Power: 6
Ralph M is on a distinguished road
Lore,
you can also go for the simpleFoam solver and then apply a rotating-BC on the wheels. No need for rotating meshes; just define the wheels as a separate patch and of you go!
Don't know the exact name for the BC, but I'm sure you'll find the name on this forum (another method is to use the BC "bananas" in your U-files. When running the case an error shows up with all the suggested BC's)
Regards,
Ralph
__________________
CFD for marine applications? Go to http://www.marinecfd.com/ and join the OF Ship Hydromechanics Group: http://www.cfd-online.com/Forums/gro...mechanics.html
Ralph M is offline   Reply With Quote

Old   March 14, 2012, 06:15
Default
  #10
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Thank you ralph.
My problem is that the tyres can be rotating parts and that's easy to achieve… The problem is related to the rims which cannot be just rotating surfaces…
lovecraft22 is offline   Reply With Quote

Old   March 15, 2012, 09:42
Default
  #11
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Hi all;
I enclosed my rims inside a surface called rotatngCells.stl

Now I think I should run cellSet and setsToZone, and eventually these will be entered inside my MRFZones, is that correct?

Should I have the rotatingCells.stl part inside my snappyHexMeshDict and have it meshed?

Thank you!
lovecraft22 is offline   Reply With Quote

Old   March 16, 2012, 03:42
Default
  #12
Senior Member
 
Elvis
Join Date: Mar 2009
Location: Sindelfingen, Germany
Posts: 577
Blog Entries: 5
Rep Power: 13
elvis is on a distinguished road
Dear Lore,

I did not do any car aerodynamic simulation so I do not know the nescessary steps to make a reasonable simulation.

I can tell you that someone in this forum knows it very well, as he worked in the past for Icon maybe Ries Bouwman http://www.cfd-online.com/Forums/members/m9819348.html
is willing to tell you a bit how VW do openfoam car simulations concerning rotating rims.

I listened to some automotive cfd engineers and I think to remember that the design of the rim and even the design of the tire tread has an huge impact on aerodynamics, there is a lot of potential on rim and tread to make good or bad car aerodynamics
elvis is online now   Reply With Quote

Old   March 16, 2012, 04:58
Default
  #13
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Thank you Elvis. I think I probably found a way on my own to do that. I'll try and run it today and in case it works ?ll post a detailed tutorial.
lovecraft22 is offline   Reply With Quote

Old   March 16, 2012, 14:16
Default
  #14
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
I'm still struggling…
I created a cylinder which encloses the rims but what should the boundary conditions be for this surface?

I'm using the k-OMEGA model.

Thank you!
lovecraft22 is offline   Reply With Quote

Old   March 17, 2012, 13:54
Default
  #15
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
I managed to get it running.
Now I need to understand what I did and also whether what I did was correct or not…

I set one wheel only to rotate and for sure its wake is quite different from the other wheels…

Maybe tomorrow I'll post a detailed list of what I did and possibly also a tutorial later on…
lovecraft22 is offline   Reply With Quote

Old   October 23, 2014, 01:10
Default
  #16
New Member
 
Yuri Vilmanis
Join Date: May 2010
Posts: 5
Rep Power: 7
madact is on a distinguished road
Quote:
Originally Posted by lovecraft22 View Post
I managed to get it running.
Now I need to understand what I did and also whether what I did was correct or not…

I set one wheel only to rotate and for sure its wake is quite different from the other wheels…

Maybe tomorrow I'll post a detailed list of what I did and possibly also a tutorial later on…
So... I know it's a very old thread, but did you ever get to doing that list or tutorial? Or perhaps there's some other resource for this problem that you could point me to? Ta
madact is offline   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
Rotating Impeller Naith FloEFD, FloWorks & FloTHERM 22 November 5, 2012 09:53
Vertical Axis Wind Turbine Rotating Domain Problems TWaung CFX 4 May 1, 2012 03:14
Help simulating a car radiator boundary conditions lhcamilo OpenFOAM Running, Solving & CFD 3 March 16, 2009 08:49
Simulating rotating surfaces Marco CFX 0 February 16, 2004 18:44


All times are GMT -4. The time now is 04:09.