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

tangential vector tolerance wall

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 13, 2017, 05:59
Default tangential vector tolerance wall
  #1
Member
 
Davide
Join Date: Jul 2015
Posts: 94
Rep Power: 9
marsa27 is on a distinguished road
Anyone knows how to change the expert parameter "tangential vector tolerance wall" in CFX? Because I see only the parameter tangential vector tolerance without "WALL"..
marsa27 is offline   Reply With Quote

Old   December 14, 2017, 08:16
Default Problem
  #2
Member
 
Davide
Join Date: Jul 2015
Posts: 94
Rep Power: 9
marsa27 is on a distinguished road
I must solve the fluidynamic inside a tire of a car to study the behaviour of the braking system. So in a steady state in CFX I set that some components have a rotating velocity. Due to the complexity of the geometry I have made an unstructured mesh, but when I starts the run CFX tells me that the angle between the specified velocity and the element surface is higher, so it suggests to increase the tolerance in the expert parameter "tangential vector tolerance wall" from its default of 20 degrees. The problem is that this expert parameter there isn't. Someone knows how to find this expert parameter that probabilly exist but is hidden???
Thank you
marsa27 is offline   Reply With Quote

Old   December 14, 2017, 18:55
Default
  #3
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,170
Rep Power: 134
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Are you sure you are not prescribing a normal velocity somewhere? The default of 20 degrees is plenty for most applications so if you infringe this it probably means something is wrong with your mesh or geometry - increasing the tolerance is rarely the appropriate response.
ghorrocks is offline   Reply With Quote

Old   December 15, 2017, 08:33
Default expert parameter
  #4
Member
 
Davide
Join Date: Jul 2015
Posts: 94
Rep Power: 9
marsa27 is on a distinguished road
No my domain is a cubic box in which there is the tire with the braking system in the interior. In a face of the cubic domain I set the velocity inlet condition, while in the tire I set a wall no slip condition with a wall rotating velocity. Do you know how to find the above expert parameter, because I would try to solve my problem without changing the mesh.. Therefore my problem is that the expert parameter "tangential vector tolerance wall" in reality I cannot find in CFX... Can you help me to find this expert parameter?
Thanks
marsa27 is offline   Reply With Quote

Old   December 15, 2017, 08:34
Default Expeet parameter
  #5
Member
 
Davide
Join Date: Jul 2015
Posts: 94
Rep Power: 9
marsa27 is on a distinguished road
Quote:
Originally Posted by ghorrocks View Post
Are you sure you are not prescribing a normal velocity somewhere? The default of 20 degrees is plenty for most applications so if you infringe this it probably means something is wrong with your mesh or geometry - increasing the tolerance is rarely the appropriate response.
No my domain is a cubic box in which there is the tire with the braking system in the interior. In a face of the cubic domain I set the velocity inlet condition, while in the tire I set a wall no slip condition with a wall rotating velocity. Do you know how to find the above expert parameter, because I would try to solve my problem without changing the mesh.. Therefore my problem is that the expert parameter "tangential vector tolerance wall" in reality I cannot find in CFX... Can you help me to find this expert parameter?
Thanks
marsa27 is offline   Reply With Quote

Old   December 15, 2017, 17:55
Default
  #6
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,170
Rep Power: 134
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
I am not on my workstation today so cannot look this up for you. But please note my previous post - this is probably caused by a meshing error which should be fixed by fixing the meshing error, not by allowing a larger tolerance.
ghorrocks is offline   Reply With Quote

Old   December 18, 2017, 08:53
Default
  #7
Member
 
Davide
Join Date: Jul 2015
Posts: 94
Rep Power: 9
marsa27 is on a distinguished road
Quote:
Originally Posted by ghorrocks View Post
I am not on my workstation today so cannot look this up for you. But please note my previous post - this is probably caused by a meshing error which should be fixed by fixing the meshing error, not by allowing a larger tolerance.
ok thanks, when you are on your workstation can you look if you find this expert parameter?
marsa27 is offline   Reply With Quote

Old   December 18, 2017, 09:48
Default
  #8
Senior Member
 
Lance
Join Date: Mar 2009
Posts: 669
Rep Power: 20
Lance is on a distinguished road
I agree with Glenn, this is probably a mesh issue.
But anyway, some expert parameters are hidden in the gui so if you really want to change the it the following trick might work:
open expert parameters, check "tangential vector tolerance", hit apply, close tab.
right click expert parameters in the tree, edit in command editor.
enter: tangential vector tolerance wall = 20.0

note: I havent tried it, it might not work, and you really should see if you can improve your mesh instead.
Lance is offline   Reply With Quote

Old   December 18, 2017, 10:42
Default Great
  #9
Member
 
Davide
Join Date: Jul 2015
Posts: 94
Rep Power: 9
marsa27 is on a distinguished road
Quote:
Originally Posted by Lance View Post
I agree with Glenn, this is probably a mesh issue.
But anyway, some expert parameters are hidden in the gui so if you really want to change the it the following trick might work:
open expert parameters, check "tangential vector tolerance", hit apply, close tab.
right click expert parameters in the tree, edit in command editor.
enter: tangential vector tolerance wall = 20.0

note: I havent tried it, it might not work, and you really should see if you can improve your mesh instead.
thank you so much I do not know how to thank you ... it was enough to follow your procedure to activate the hidden expert parameter
marsa27 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
Centrifugal fan-reverse flow in outlet lesds to a mass in flow field xiexing CFX 3 March 29, 2017 10:00
Error finding variable "THERMX" sunilpatil CFX 8 April 26, 2013 07:00
Water subcooled boiling Attesz CFX 7 January 5, 2013 03:32
[Commercial meshers] tmerge utility creates unwanted interface/walls comes in the final mesh Shoonya OpenFOAM Meshing & Mesh Conversion 11 January 20, 2012 06:23
UDF for wall slipping HFLUENT Fluent UDF and Scheme Programming 0 April 27, 2011 12:03


All times are GMT -4. The time now is 20:46.