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

Aerodynamic simulation

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 28, 2011, 08:28
Default Aerodynamic simulation
  #1
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
Hi everybody,
I have to make an aerodynamic simulation, how can I build a control volume (such as a wind tunnel)after importing the geometry I have to simulate?
then, once I have made this system (body + wind tunnel) which is the best way to operate: give solid properties to body and fluid to control volume, or make a boolean operation to subtract body from control volume and give fluid properties to the resulting volume?
thank you!
Maicol is offline   Reply With Quote

Old   April 28, 2011, 08:39
Default
  #2
Super Moderator
 
Ryne Whitehill
Join Date: Aug 2009
Posts: 313
Rep Power: 9
rwryne is on a distinguished road
Quote:
Originally Posted by Maicol View Post
Hi everybody,
I have to make an aerodynamic simulation, how can I build a control volume (such as a wind tunnel)after importing the geometry I have to simulate?
then, once I have made this system (body + wind tunnel) which is the best way to operate: give solid properties to body and fluid to control volume, or make a boolean operation to subtract body from control volume and give fluid properties to the resulting volume?
thank you!

Import the geometry as a part, create a box part to the size you want, then do a boolean subtract with the box part as the "target part"
rwryne is offline   Reply With Quote

Old   April 28, 2011, 10:32
Default
  #3
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
very kind of you, many thanks
Maicol is offline   Reply With Quote

Old   April 29, 2011, 05:30
Default
  #4
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
I tried the way you suggested, I subtracted a sphere from a tunnel (in STAR DESIGN), it works correctly.
I tried onother way, too: import two separate bodies in STAR CCM, but i have a problem to asign properties to singular bodies (such as physical properties, mesh sizing etc..): when I am importing geometries, which is the best way to import: create a new region or a new part?
Have you ever made something similar?
I really thank everyone of you is interested in giving me an answer
Maicol is offline   Reply With Quote

Old   April 29, 2011, 09:52
Default
  #5
Super Moderator
 
Ryne Whitehill
Join Date: Aug 2009
Posts: 313
Rep Power: 9
rwryne is on a distinguished road
Quote:
Originally Posted by Maicol View Post
I tried the way you suggested, I subtracted a sphere from a tunnel (in STAR DESIGN), it works correctly.
I tried onother way, too: import two separate bodies in STAR CCM, but i have a problem to asign properties to singular bodies (such as physical properties, mesh sizing etc..): when I am importing geometries, which is the best way to import: create a new region or a new part?
Have you ever made something similar?
I really thank everyone of you is interested in giving me an answer

I prefer to import as a part. You then need to create an empty region with boundaries and assign the surfaces of the part to the region boundaries. Then do Mesh->Initialize Meshing, which transfers the geometric data from the Part level to the Region level.
It is a good habit to import as a part as I have heard that eventually CD-Adapco is going to do away with the import as region.
rwryne is offline   Reply With Quote

Old   April 30, 2011, 11:03
Default
  #6
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
Thank you Ryne!
Maicol is offline   Reply With Quote

Old   May 1, 2011, 07:32
Default
  #7
Senior Member
 
Join Date: Oct 2009
Location: Germany
Posts: 637
Rep Power: 12
abdul099 is on a distinguished road
Quote:
Originally Posted by rwryne View Post
I prefer to import as a part. You then need to create an empty region with boundaries and assign the surfaces of the part to the region boundaries. Then do Mesh->Initialize Meshing, which transfers the geometric data from the Part level to the Region level.
It is a good habit to import as a part as I have heard that eventually CD-Adapco is going to do away with the import as region.
When you've imported a part, you can right-click on it and choose either "set region" (older versions) or "assign parts to regions" (newer versions). That helps much saving time as you don't have to create a region and boundaries by hand and assing surfaces to boundaries.
abdul099 is offline   Reply With Quote

Old   May 2, 2011, 06:25
Default
  #8
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
Thanks for your suggestion Abdul...I tried this way too I have to define 2 mesh and 2 physic cases to define properties for 2 parts, isn't it?
Maicol is offline   Reply With Quote

Old   May 2, 2011, 08:17
Default
  #9
Super Moderator
 
Ryne Whitehill
Join Date: Aug 2009
Posts: 313
Rep Power: 9
rwryne is on a distinguished road
Quote:
Originally Posted by abdul099 View Post
When you've imported a part, you can right-click on it and choose either "set region" (older versions) or "assign parts to regions" (newer versions). That helps much saving time as you don't have to create a region and boundaries by hand and assing surfaces to boundaries.

Yes, thank you for correcting me, this is how I typically do it. Much easier than doing it by hand.
rwryne is offline   Reply With Quote

Old   May 3, 2011, 03:34
Default
  #10
Senior Member
 
Join Date: Oct 2009
Location: Germany
Posts: 637
Rep Power: 12
abdul099 is on a distinguished road
Quote:
Originally Posted by Maicol View Post
Thanks for your suggestion Abdul...I tried this way too I have to define 2 mesh and 2 physic cases to define properties for 2 parts, isn't it?
No. As long as they share the same physics, you need only one physics continuum. But you shouldn't have two ISOLATED parts, there should be some connection like interfaces between them.
And for the mesh continuum, you usually use only one as well as long as you don't want to give completely different values or models to different regions.

Will you have two regions? When doing so, is it necessary to have two regions?
abdul099 is offline   Reply With Quote

Old   May 3, 2011, 07:58
Default
  #11
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
Quote:
Originally Posted by abdul099 View Post
No. As long as they share the same physics, you need only one physics continuum. But you shouldn't have two ISOLATED parts, there should be some connection like interfaces between them.
And for the mesh continuum, you usually use only one as well as long as you don't want to give completely different values or models to different regions.

Will you have two regions? When doing so, is it necessary to have two regions?
in case of a air flow on a solid body i should have a physics continuum for solid part and a physics continuum to define gas properties..am i saying a right thing?
Maicol is offline   Reply With Quote

Old   May 3, 2011, 08:30
Default
  #12
Super Moderator
 
Ryne Whitehill
Join Date: Aug 2009
Posts: 313
Rep Power: 9
rwryne is on a distinguished road
Quote:
Originally Posted by Maicol View Post
in case of a air flow on a solid body i should have a physics continuum for solid part and a physics continuum to define gas properties..am i saying a right thing?
If you are only interseted in the air flow, then you do not need a continuum for the solid part. You will only need the 2nd continuum if you are intersted in something like the heat transfer through the solid.
rwryne is offline   Reply With Quote

Old   May 3, 2011, 09:48
Default
  #13
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
Quote:
Originally Posted by rwryne View Post
If you are only interseted in the air flow, then you do not need a continuum for the solid part. You will only need the 2nd continuum if you are intersted in something like the heat transfer through the solid.
Ok..however I have to mesh both the "solid" region and the fluid region, isn't it?
Maicol is offline   Reply With Quote

Old   May 3, 2011, 10:51
Default
  #14
Super Moderator
 
Ryne Whitehill
Join Date: Aug 2009
Posts: 313
Rep Power: 9
rwryne is on a distinguished road
Quote:
Originally Posted by Maicol View Post
Ok..however I have to mesh both the "solid" region and the fluid region, isn't it?
Think about it in terms of volume mesh, not surface mesh. You only need a volume mesh where your interests lie. If you are just interested in the aerodynamic solution, you only need a volume mesh in the flow field.

The volume mesh of the flow field will use the surface boundaries of the solid body.
rwryne is offline   Reply With Quote

Old   May 5, 2011, 02:21
Default
  #15
New Member
 
Michele
Join Date: Apr 2011
Posts: 17
Rep Power: 6
Maicol is on a distinguished road
thank you Ryne, I will check the simulation using one volume mesh
Maicol 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
Aerodynamic simulation Amech1423 NUMECA 1 June 5, 2011 06:13
Simulation of a complex wing in solidworks flow simulation niels1900 FloEFD, FloWorks & FloTHERM 6 April 20, 2011 10:44
GUI crash and simulation engine still running RPJones FLOW-3D 2 November 9, 2010 09:18
velocity profile export from a simulation onto another sudhirlv STAR-CCM+ 1 September 12, 2010 18:57
strange simulation error Ralf Schmidt FLUENT 2 May 4, 2007 13:02


All times are GMT -4. The time now is 15:00.