Global Reductions
 

I'm trying to use a global reduction, specifically PRF_GRSUM1, in my parallel interpreted UDF. Seems that it should be pretty straightforward, but I'm getting errors.

I went digging around to find how it's defined, and found that prf.h has , but no prototype. reductions.h has a prototype, but if I include it, I get the following:

Does anyone know anything about how this is all put together? Why isn't this covered by including udf.h?

Dear Andrew,

I am facing the same problem interpreting in Fluent's parallel mode. I have tried to avoid multiple definition by preprocessor statements in the usual pattern. But it didn't prevent reinterpreting of the files.
Have you been able to solve your problem?

Best regards,

Rudi

In the end, I ended up compiling my UDF. Not sure if that's what fixed it, or if I did something else, but my final UDF #includes udf.h and nothing else.

Upon your hint, I have removed sg_ls.h from includes. Instead I 'exported', which is to say I copied, the definition I needed into my file.

Interpreting it went through without redefinition error :-) Thanks!

Rudi

I met the same problem
 

I have found the reductions.h,but,I can't find the define of the MPT_GDSUM1,could you tell me the define of the MPT_GDSUM1

use PRF_GRSUM1 for global redution

read ansys fluent customization manual for more details

best regards

Dear AlexanderZ:

Thank you so much for your answer.
The advice you suggested I have tried, but it still goes wrong.
It shows MPT_gdsum1: no function prototype.
I have no idea how to adjust my UDF.
My code as follow, could you tell me what is going wrong?

#include "udf.h"
#include "prf.h"

DEFINE_EXECUTE_AT_END(centroid)
{
#if !RP_HOST
real wcx = 0.0;
real wcy = 0.0;
real va_liq = 0.0;
real cx, cy;
real x, y;
cell_t c;
real z[ND_ND];
Domain *subdomain= Get_Domain(3);
Thread *t;
#endif
#if !RP_NODE
FILE *fout1;
FILE *fout2;
#endif
#if !RP_HOST
thread_loop_c(t,subdomain)
{
begin_c_loop(c, t)
{
if(0.5<=C_VOF(c,t)&&C_VOF(c,t)<=1.0)
{
va_liq = va_liq + C_VOLUME(c,t);
C_CENTROID(z,c,t);
wcx = wcx + z[0]*C_VOLUME(c,t);
wcy = wcy + z[1]*C_VOLUME(c,t);
}
}
end_c_loop(c, t)
}
va_liq = PRF_GDSUM1(va_liq);
wcx = PRF_GDSUM1(wcx);
wcy = PRF_GDSUM1(wcy);
cx = wcx/va_liq;
cy = wcy/va_liq;
#endif
#if !RP_NODE
fout1 = fopen("X-centroid of liquid.txt","a");
fout2 = fopen("Y-centroid of liquid.txt","a");
#endif
node_to_host_real_2(cx, cy);
#if RP_HOST
fprintf(fout1,"%g,%g\n",CURRENT_TIME,cx);
fprintf(fout2,"%g,%g\n",CURRENT_TIME,cy);
#endif
#if !RP_NODE
fclose(fout1);
fclose(fout2);
Message("\n X-centroid of liquid = %g\n", cx);
Message("\n Y-centroid of liquid = %g\n", cy);
#endif

}
Thanks a lot.
Best regards.
Wang Lu

this code is complied with no error

best regards

As I've told, compile this code and try to run it

best regards

Thanks a lot for your answer.
Best regards!
Wang Lu

Dear AlexanderZ:
Thank you for your answer.
I still can not compile my code.
When I compile my code ,it shows error like "The UDF library you are trying to load (libudf) is not compiled for parallel use on the current platform (win64)".
Do you know what's wrong?
Beat regards!
Wang Lu

this code, which I've attached, is compiled well

to compile code:
run fluent from visual studio command prompt (or SDK command prompt) -> user defined -> functions -> compiled -> BUILD

best regards

Dear AlexanderZ:
Thank you for your answer.I just did what you have told,but it still shows wrong.I made a video which recorded what I did and upload on the website as follow,so that you can know what I have done.

https://user.qzone.qq.com/651668162/main
Best regards!
Wang Lu

Dear AlexanderZ

I need to change the website to
https://user.qzone.qq.com/651668162

Best regards!
Wang Lu

Dear AlexanderZ
Today,I try to compile my UDF,and run my Fluent. The UDF can be compiled,but it can't output the file, and the case interrupt.I think my UDF still have the coding error. Could you help me correct my UDF.
Blessing to you.
WangLu

Show what is written on your screen after you click "build". (not what happens after you click "load").

It might be in your video, but I am not going to watch a video.

Dear pakk:
Thank you for your answer.It shows as follow:
Copied F:\wldaoliuban\case\25_4/F:\wldaoliuban\case\25_4\centroid_parallel_wl.c to libudf\src
Copied F:\wldaoliuban\case\25_4/F:\wldaoliuban\case\25_4\udf.h to libudf\src
Creating user_nt.udf file for 3ddp_host ...
(system "copy "D:\ANSYS\ANSYS Inc\v180\fluent"\fluent18.0.0\src\udf\makefile_nt. udf "libudf\win64\3ddp_host\makefile" ")
ÒѸ´ÖÆ 1 ¸öÎļþ¡£
(chdir "libudf")(chdir "win64\3ddp_host")# Generating ud_io1.h
centroid_parallel_wl.c
# Generating udf_names.c because of makefile centroid_parallel_wl.obj
udf_names.c
# Linking libudf.dll because of makefile user_nt.udf udf_names.obj centroid_parallel_wl.obj
Microsoft (R) Incremental Linker Version 12.00.21005.1
Copyright (C) Microsoft Corporation. All rights reserved.

ÕýÔÚ´´½¨¿â libudf.lib ºÍ¶ÔÏó libudf.exp
Creating user_nt.udf file for 3ddp_node ...
(system "copy "D:\ANSYS\ANSYS Inc\v180\fluent"\fluent18.0.0\src\udf\makefile_nt. udf "libudf\win64\3ddp_node\makefile" ")
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(chdir "libudf")(chdir "win64\3ddp_node")# Generating ud_io1.h
centroid_parallel_wl.c
# Generating udf_names.c because of makefile centroid_parallel_wl.obj
udf_names.c
# Linking libudf.dll because of makefile user_nt.udf udf_names.obj centroid_parallel_wl.obj
Microsoft (R) Incremental Linker Version 12.00.21005.1
Copyright (C) Microsoft Corporation. All rights reserved.

ÕýÔÚ´´½¨¿â libudf.lib ºÍ¶ÔÏó libudf.exp

Done.
Best regards!
WangLu

try to run this code
if there still be problems -> show you console output

best regards

Dear AlexanderZ:
Thank you so much to help me correct my UDF. I am so happy to see my case run well with the UDF. But it still has a little error. The result in the text the case output is different with the result in the serial veision.
It shows :"0.01,-1.#IND"
In the serial version, it shows:"0.01,0.053456"
Do you know what's wrong?
Thank you again.
Best Regards!
Wanglu