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

how to determine the C0 and C1 on interior wall in fluent UDF

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

Like Tree2Likes
  • 1 Post By A CFD free user
  • 1 Post By pakk

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 14, 2015, 04:04
Default how to determine the C0 and C1 on interior wall in fluent UDF
  #1
New Member
 
zhouxman
Join Date: Dec 2014
Posts: 12
Rep Power: 8
zhouxman is on a distinguished road
Hi,everybody,
how to determine the C0 and C1 on interior wall in fluent UDF?
zhouxman is offline   Reply With Quote

Old   April 15, 2015, 18:39
Default
  #2
Senior Member
 
A CFD free user's Avatar
 
A-A Azarafza
Join Date: Jan 2013
Posts: 226
Rep Power: 11
A CFD free user is on a distinguished road
Quote:
Originally Posted by zhouxman View Post
Hi,everybody,
how to determine the C0 and C1 on interior wall in fluent UDF?

Dear Friend,

c0 = F_C0(f,t) and c1 = F_C1(f,t) are actually two macros are used to access to adjacent cell thread for faces (walls or interior). For wall faces, only c0 is available; however, for interior faces both c0 and c1 can be accessed via the right-hand rule. To determine the c0 and c1 thread on interior faces, you need to find the area normal vector. The cells out of which the area normal vector is pointing to is defined as c0 thread and the ones into which the area normal vector is pointing to is called c1 thread. So to get the right c0 and c1, first you should get the pertinent face thread using face look_up macro ant then employ the right-hand rue. To make it clear, see the schematic in attachment.

I hope it helps
Attached Images
File Type: jpg 111.JPG (10.3 KB, 85 views)
Vicky3141 likes this.
__________________
Regard yours
A CFD free user is offline   Reply With Quote

Old   April 15, 2015, 22:12
Default
  #3
New Member
 
zhouxman
Join Date: Dec 2014
Posts: 12
Rep Power: 8
zhouxman is on a distinguished road
Quote:
Originally Posted by A CFD free user View Post
Dear Friend,

c0 = F_C0(f,t) and c1 = F_C1(f,t) are actually two macros are used to access to adjacent cell thread for faces (walls or interior). For wall faces, only c0 is available; however, for interior faces both c0 and c1 can be accessed via the right-hand rule. To determine the c0 and c1 thread on interior faces, you need to find the area normal vector. The cells out of which the area normal vector is pointing to is defined as c0 thread and the ones into which the area normal vector is pointing to is called c1 thread. So to get the right c0 and c1, first you should get the pertinent face thread using face look_up macro ant then employ the right-hand rue. To make it clear, see the schematic in attachment.

I hope it helps
dear,
thanks for your reply!
as show in your schematic , is it means the c0 and c1 are fixed as shown in your schematic? how about the THREAD_T0 and THREAD_T1 ?

best regard
zhouxman is offline   Reply With Quote

Old   April 17, 2015, 04:35
Default how to determine the 'area normal vector'
  #4
New Member
 
zhouxman
Join Date: Dec 2014
Posts: 12
Rep Power: 8
zhouxman is on a distinguished road
Quote:
Originally Posted by A CFD free user View Post
Dear Friend,

c0 = F_C0(f,t) and c1 = F_C1(f,t) are actually two macros are used to access to adjacent cell thread for faces (walls or interior). For wall faces, only c0 is available; however, for interior faces both c0 and c1 can be accessed via the right-hand rule. To determine the c0 and c1 thread on interior faces, you need to find the area normal vector. The cells out of which the area normal vector is pointing to is defined as c0 thread and the ones into which the area normal vector is pointing to is called c1 thread. So to get the right c0 and c1, first you should get the pertinent face thread using face look_up macro ant then employ the right-hand rue. To make it clear, see the schematic in attachment.

I hope it helps
dear,
how to determine the 'area normal vector'
zhouxman is offline   Reply With Quote

Old   April 17, 2015, 04:45
Default
  #5
Senior Member
 
Join Date: Nov 2013
Posts: 1,629
Rep Power: 22
pakk will become famous soon enough
To answer your question, it would help what you mean with "determine".

Do you want to know how to calculate the area normal vector in a script?
Or do you want to know what "area normal vector" means?
Or something else?
pakk is offline   Reply With Quote

Old   April 18, 2015, 07:32
Default Dear pakk,
  #6
New Member
 
zhouxman
Join Date: Dec 2014
Posts: 12
Rep Power: 8
zhouxman is on a distinguished road
Quote:
Originally Posted by pakk View Post
To answer your question, it would help what you mean with "determine".

Do you want to know how to calculate the area normal vector in a script?
Or do you want to know what "area normal vector" means?
Or something else?
Dear pakk,
I want to know how to calculate the area normal vector in a script and the means of "area normal vector" .
Thanks
zhouxman is offline   Reply With Quote

Old   April 20, 2015, 03:57
Default
  #7
Senior Member
 
Join Date: Nov 2013
Posts: 1,629
Rep Power: 22
pakk will become famous soon enough
Probably the words "area normal vector" did not appear out of nowhere into your brain. You must have read it somewhere.

In fact, the only place I know where these words are used is in the Fluent manual. So I suggest you look there.
pakk is offline   Reply With Quote

Old   April 26, 2018, 11:11
Default THREAD_SHADOW(t) flluent udf
  #8
New Member
 
Morteza
Join Date: Aug 2016
Posts: 2
Rep Power: 0
Morteza60 is on a distinguished road
Hello all

I would like to know what is the functionality of THREAD_SHADOW(t) macro? I have searched little bit but i did not find any useful information. Can anybody demonstrate above macro in a UDF?
Morteza60 is offline   Reply With Quote

Old   April 26, 2018, 11:18
Default
  #9
Senior Member
 
Join Date: Nov 2013
Posts: 1,629
Rep Power: 22
pakk will become famous soon enough
If you have a shadow wall in your simulation (an internal interface between a solid volume and a fluid volume), then in Fluent's internal storage, these are to boundaries:
* The solid-to-fluid boundary, as seen from the solid
* The fluid-to-solid boundary, as seen from the fluid

If, in a UDF, face thread "ft" refers to a solid-to-fluid boundary, then THREAD_SHADOW(ft) refers to the corresponding fluid-to-solid boundary.
If, in a UDF, face thread "ft" refers to a fluid-to-solid boundary, then THREAD_SHADOW(ft) refers to the corresponding solid-to-fluid boundary.
If, in a UDF, face thread "ft" does not refer to one of these two boundaries, then THREAD_SHADOW(ft) is NULL.
Mohamed Mousa likes this.
pakk is offline   Reply With Quote

Old   April 26, 2018, 17:51
Default THREAD_SHADOW(t) flluent udf
  #10
New Member
 
Morteza
Join Date: Aug 2016
Posts: 2
Rep Power: 0
Morteza60 is on a distinguished road
Thank you very much pakk

Could you please make an example of fluid-solid domain? the solid domain should be part of simulation and don't necessary have to be a wall. am I right?
like gas in vicinity of porous media?
Morteza60 is offline   Reply With Quote

Old   September 1, 2019, 09:36
Default Determine F_C0 and F_C1 on an interior wall
  #11
New Member
 
Jason FANG
Join Date: Aug 2019
Posts: 6
Rep Power: 3
Jasonf is on a distinguished road
Hi everyone!
I am also wondering how to determine the macros of adjacent cells, F_C0 and F_C1, on an interior wall (interface between fluid and solid zones) as illustrated in Fig. I heard of the right-hand law, but I do not know how to use it. Is there any simple way to solve this problem?
Thanks for any help!
Attached Images
File Type: jpg interface.jpg (11.3 KB, 31 views)
Jasonf 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



All times are GMT -4. The time now is 16:23.