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Obtain equation residuals in UDF

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Old   February 1, 2010, 15:26
Default Obtain equation residuals in UDF
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Robert Bressan
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Hello!

I'm writing an UDF that makes an optimization.
So every iteration, it must check if there was convergence in the solver, so I can make the proper changes in my profiles.

Is there a way to return the current solver residuals?

Regards,
Robert
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Old   February 9, 2010, 08:20
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Well not in udf but here is a scheme line that gives you the residuals for the specified or current iteration (see also Wiki Fluent Scheme):

Code:
(get-residual-norms-at 1001)
(solver-residuals)
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Old   March 9, 2010, 04:06
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Quote:
Originally Posted by robert.bressan View Post
Hello!

I'm writing an UDF that makes an optimization.
So every iteration, it must check if there was convergence in the solver, so I can make the proper changes in my profiles.

Is there a way to return the current solver residuals?

Regards,
Robert
This is an example to print the residuals on the console.
#include "udf.h"
DEFINE_ON_DEMAND(residual_list)
{
int nw;
real scaled_res;
Domain*domain=Get_Domain(1);
for(nw=0; nw<MAX_EQNS; ++nw)
{
if(strlen(DOMAIN_EQN_LABEL(domain,nw))>0)
{
if(0==DOMAIN_RES_SCALE(domain,nw)[nres-1])
DOMAIN_RES_SCALE(domain,nw)[nres-1]=1;
scaled_res=DOMAIN_RES(domain,nw)[nres-1]/DOMAIN_RES_SCALE(domain,nw)[nres-1];
Message("%s equation,residual=%g\n",DOMAIN_EQN_LABEL(domain,nw ),scaled_res);
}
}
}
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Old   March 9, 2010, 04:34
Default What is nres?
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Hi Ji,
Nice to see some undocumented macros at use, but what is 'nres' variable representing?
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Old   March 9, 2010, 23:25
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Quote:
Originally Posted by dmoroian View Post
Hi Ji,
Nice to see some undocumented macros at use, but what is 'nres' variable representing?
nres is the current number of residuals.
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Old   April 1, 2012, 02:49
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Quote:
Originally Posted by gearboy View Post
nres is the current number of residuals.
Dear my friends.Now, a similar problem I had come acrossed when edit a udf, while i copy this code and then try to compile as executable progame, an issue come out, the fluent tell me that subscript required array or poiter types. I think it maybe caused by the nres. Who can tell me how to treat it. I only want to obtain the residuals on the current time in my udf.
If anybody could have the same question and have solve it,please help me. Thank you.
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Old   April 1, 2012, 03:02
Default ...post the error
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Could you post the error you get not from your own memory, but from the computer screen?
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Old   April 1, 2012, 03:11
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Quote:
Originally Posted by dmoroian View Post
Could you post the error you get not from your own memory, but from the computer screen?
Ok
(system "copy "C:\PROGRA~1\ANSYSI~1\v130\fluent"\fluent13.0.0\sr c\makefile_nt.udf "libudf\win64\2ddp\makefile" ")
已复制 1 个文件。
(chdir "libudf")()
(chdir "win64\2ddp")()
# Generating ud_io1.h
test2.c
..\..\src\test2.c(11) : error C2109: 下标要求数组或指针类型
..\..\src\test2.c(12) : error C2109: 下标要求数组或指针类型
..\..\src\test2.c(13) : error C2109: 下标要求数组或指针类型
..\..\src\test2.c(13) : error C2109: 下标要求数组或指针类型
Done.
"下标要求数组或指针类型/chinese" means "subscript requried arrays or pointer types"
Thank you!!
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Old   April 1, 2012, 10:08
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Is it possible to post the code? Apparently you're trying to use as array something that's not.
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Old   April 2, 2012, 09:47
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Quote:
Originally Posted by dmoroian View Post
Is it possible to post the code? Apparently you're trying to use as array something that's not.

I am very appreciated for your help. In order to avoid to determine the convergence in my udf according to the residuals, I had choosen another
variable at the exit boundary ,and by monitoring its change to do the next work.
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