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

Macros for yplus, ystar, Ustar

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 23, 2011, 12:01
Default Macros for yplus, ystar, Ustar
  #1
New Member
 
N/A
Join Date: Aug 2011
Posts: 2
Rep Power: 0
Seppl Huber is on a distinguished road
Hello,

I want to access the macro for yplus, ystar and Ustar in Fluent in my udf.
Does anyone know these macros? I am looking for a macro similar like C_R(c,t) to access the density in a cell.

Thanks in advance,
Seppl

Hello, I found the solution for yplus and U_tau (=friction velocity?)

F_STORAGE_R(f,t,SV_WALL_YPLUS)
F_STORAGE_R(f,t,SV_WALL_YPLUS_UTAU)

Last edited by Seppl Huber; August 24, 2011 at 05:56.
Seppl Huber is offline   Reply With Quote

Old   September 29, 2011, 13:36
Default
  #2
New Member
 
Join Date: Jul 2011
Posts: 2
Rep Power: 0
renli05 is on a distinguished road
hi,Seppl
Do you know how to define yplus in Custom field function or UDF? The yplus in Fluent is only on the wall. I want to get a X-Y plot of uplus verus yplus along the wall normal direction. Could you give some sugguestion.
Thanks a lot.
renli05 is offline   Reply With Quote

Old   November 4, 2011, 04:44
Default
  #3
Member
 
john
Join Date: Nov 2010
Posts: 50
Rep Power: 16
johnwinter is on a distinguished road
Hi Renli,

I guess you can calculate u* (and therefore y+) only near wall. Because by definition
u* = sqrt(shear stress/rho)

From this you can get shear stress only near wall.. right?.. if so it may not good representation to plot y+ along wall normal.

John
johnwinter is offline   Reply With Quote

Old   November 4, 2011, 11:33
Default
  #4
New Member
 
Join Date: Feb 2011
Posts: 7
Rep Power: 15
Gold is on a distinguished road
Quote:
Originally Posted by Seppl Huber View Post
Hello,

I want to access the macro for yplus, ystar and Ustar in Fluent in my udf.
Does anyone know these macros? I am looking for a macro similar like C_R(c,t) to access the density in a cell.

Thanks in advance,
Seppl

Hello, I found the solution for yplus and U_tau (=friction velocity?)

F_STORAGE_R(f,t,SV_WALL_YPLUS)
F_STORAGE_R(f,t,SV_WALL_YPLUS_UTAU)



Dear All

i want to write a udf that stores the yplus in a UDMI for using that and get the USTAR at the boundaries, i dont know how use SV_WALL_YPLUS_UTAU;
d = Get_Domain(1);

thread_loop_c(t,d)
{
begin_c_loop(c,t)
{

C_UDMI(c,t,1)=C_STORAGE_R(f,t,SV_WALL_YPLUS_UTAU);

}
end_c_loop(c,t)
}

could you please give me an idea about that please

thanks
Gold is offline   Reply With Quote

Old   November 5, 2011, 06:46
Default
  #5
Member
 
john
Join Date: Nov 2010
Posts: 50
Rep Power: 16
johnwinter is on a distinguished road
Quote:
Originally Posted by Seppl Huber View Post
Hello,

I want to access the macro for yplus, ystar and Ustar in Fluent in my udf.
Does anyone know these macros? I am looking for a macro similar like C_R(c,t) to access the density in a cell.

Thanks in advance,
Seppl

Hello, I found the solution for yplus and U_tau (=friction velocity?)

F_STORAGE_R(f,t,SV_WALL_YPLUS)
F_STORAGE_R(f,t,SV_WALL_YPLUS_UTAU)
Hi Huber,

When i try use the said macros i got the following error.

Error:
FLUENT received fatal signal (ACCESS_VIOLATION)
1. Note exact events leading to error.
2. Save case/data under new name.
3. Exit program and restart to continue.
4. Report error to your distributor.
Error Object: ()

Could you please explain how to use them in udf, is it like
F_STORAGE_R(f,t,SV_WALL_YPLUS)[1]?? or any header file need to be included to access those macros??

Thanks
John
johnwinter is offline   Reply With Quote

Old   March 23, 2012, 01:57
Default
  #6
Member
 
Ming Cai
Join Date: Mar 2011
Posts: 50
Rep Power: 15
mingersai is on a distinguished road
Quote:
Originally Posted by johnwinter View Post
Hi Huber,

When i try use the said macros i got the following error.

Error:
FLUENT received fatal signal (ACCESS_VIOLATION)
1. Note exact events leading to error.
2. Save case/data under new name.
3. Exit program and restart to continue.
4. Report error to your distributor.
Error Object: ()

Could you please explain how to use them in udf, is it like
F_STORAGE_R(f,t,SV_WALL_YPLUS)[1]?? or any header file need to be included to access those macros??

Thanks
John
Because it's totally wrong....
it loops all cell threads but the macro accesses face values....
In my case, I defined search algorithm which gives wall value to all cells perpendicular to it as roni mentioned. but i'm not sure if it's the right way though...
mingersai is offline   Reply With Quote

Old   October 12, 2020, 05:26
Default
  #7
New Member
 
Join Date: Jun 2020
Posts: 6
Rep Power: 6
BryceLos is on a distinguished road
Quote:
Originally Posted by mingersai View Post
Because it's totally wrong....
it loops all cell threads but the macro accesses face values....
In my case, I defined search algorithm which gives wall value to all cells perpendicular to it as roni mentioned. but i'm not sure if it's the right way though...
Hi,

Could you please share the codes for yplus?

many thanks,
Bryce
BryceLos is offline   Reply With Quote

Reply

Tags
udf macro


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
Tecplot360 - Macros calling Macros? eRzBeNgEl CFX 1 April 15, 2011 07:32
help with macros F_ID and C_ID Jack Martinez FLUENT 0 August 19, 2007 09:27
What are UDF macros C_T_S , C_T_AP,...???? Asghari FLUENT 0 January 28, 2007 11:54
Orientation of Face Variable Macros hirokata FLUENT 0 February 17, 2006 01:12
ystar and yplus sarah_ron FLUENT 1 December 16, 2004 12:19


All times are GMT -4. The time now is 01:03.