[nimadeCFD]

Hello everyone. This is my first thread to ask for help. I do appreciate any help from you. In fact, I tried to search any useful tips by searching relevant threads in cfdOnline as well as on Google, but I failed. Therefore, the question troubling me for a long time is posted here as bellows:
1. I wanna parallelize a piece UDF code (it can be interpreted/compiled in serial and is shown at the end) to enable it run in HPC environment. However, when I add '#if !RP_HOST and #endif' and open Fluent in parallel, I receive the notice on the TUI after compiling the UDF:
(chdir "libudf3")(chdir "win64\3ddp_host")# Linking libudf.dll because of makefile user_nt.udf udf_names.obj nanofluid-parallel.obj
Microsoft (R) Incremental Linker Version 10.00.40219.01
Copyright (C) Microsoft Corporation. All rights reserved.


udf_names.obj : error LNK2001:
udf_names.obj : error LNK2001:
udf_names.obj : error LNK2001:
udf_names.obj : error LNK2001:
libudf.dll : fatal error LNK1120: 4
udf_names.c and user_nt.udf files in 3ddp_node are upto date.
(system "copy "E:\ansys18\ANSYSI~1\v180\fluent"\fluent18.0.0\src \udf\makefile_nt.udf "libudf3\win64\3ddp_node\makefile" ")
1 file(s) copied.
(chdir "libudf3")(chdir "win64\3ddp_node")# Linking libudf.dll because of makefile user_nt.udf udf_names.obj nanofluid-parallel.obj
Microsoft (R) Incremental Linker Version 10.00.40219.01
Copyright (C) Microsoft Corporation. All rights reserved.


udf_names.obj : error LNK2001:
udf_names.obj : error LNK2001:
udf_names.obj : error LNK2001:
udf_names.obj : error LNK2001:
libudf.dll : fatal error LNK1120: 4
2. Then I tried to load it, and certainly got an error:
Error: The UDF library you are trying to load (libudf3) is not compiled for parallel use on the current platform (win64).\n\nThe system cannot find the file specified.
\n\nF:\...*\libudf3\win64\3ddp_host\libudf.dll
Error Object: #f
3. My code:
#include "udf.h"
#include "math.h"
DEFINE_PROFILE(flux_profile,t,i)
{
real x[ND_ND];
real z;
real y;
real xx;
real theta;
face_t f;
#if !RP_HOST
begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
xx=x[0];
y=x[1];
z=x[2];
theta=atan(y/xx);
if(xx>0)
F_PROFILE(f,t,i)=960000*cos(theta);
}
end_f_loop(f,t)
#endif
}

Sincerely thank you for any favour.

[vinerm]

There are three simple changes required to be made

1. Remove math.h. It is is not required but is not the cause of error
2. Move #if !RP_HOST just after the opening brace. This is the root cause.
3. While using profile UDF for a boundary, the numbers are assigned only by the UDF. So, for any faces lying on negative x the field values could be very high because those are not being explicitly given in the code. So, add an else after the if and provide values accordingly. A better approach is to create a new real variable, assign value to this variable within if - else and then assign F_PROFILE to that variable. If there are no faces with negative x-coordinate then if condition is not required.

[nimadeCFD]

Thank you, vinerm.
I modify the UDF as follow. However, the error still exist. Now I am wondering there is something wrong in the fluent software. I use Fluent 18.0 in Windows 10.

Code:

#include "udf.h"

DEFINE_PROFILE(flux_profile,t,i)
{
#if !RP_HOST
real x[ND_ND];
real z;
real y;
real xx;
real theta;
face_t f;
begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
xx=x[0];
y=x[1];
z=x[2];
theta=atan(y/xx);
if(xx>0)
F_PROFILE(f,t,i)=960000*exp(-18*pow((z-0.5),2))*cos(theta);
else
F_PROFILE(f,t,i)= 0.;
}
end_f_loop(f,t)
#endif
}

[vinerm]

The error being shown is related to linking, i.e., it is unable to find the references for the functions used. Can you attach your C file in the post instead?

[nimadeCFD]

Thank you for your prompt reply.
I will attach C files here. But I don't know what specific files I need to submit. Sorry. Are the header files like udfconfig or udfconfig-host I should attach? which I find exist in the same directory except the UDF code attached in the former answer.

Apologize again since I don't know how and what need to be attached.

[vinerm]

Only the C file. And also a snapshot of the window where you build the library, i.e., the window where you have Build Icon.

[nimadeCFD]

C code shown as below:
#include "udf.h"

DEFINE_PROFILE(flux_profile,t,i)
{
#if !RP_HOST
real x[ND_ND];
real z;
real y;
real xx;
real theta;
face_t f;
begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
xx=x[0];
y=x[1];
z=x[2];
theta=atan(y/xx);
if(xx>0)
F_PROFILE(f,t,i)=960000*exp(-18*pow((z-0.5),2))*cos(theta);
else
F_PROFILE(f,t,i)= 0.;
}
end_f_loop(f,t)
#endif
}

I paste the snipped capture here. But I doubt whether it is successful or not.

Thank you again

[nimadeCFD]

[vinerm]

Could you attach .c file instead of copying the code in the post? It makes a difference.

[nimadeCFD]

Thank you, Vinerm.

I cost about one and half hour, but I still don't know how to upload a file in CFDonline.

I am a rookie.

Sincerely apologize.

[nimadeCFD]

https://pan.baidu.com/s/1efBlb7hTzMijEzcVOO84rw

[nimadeCFD]

Dear Vinerm,

I doubt whether the file I attached is not what you want to see. For convenience, I will send you the C file via email if you permit.

[vinerm]

Instead of using third party links, I'd suggest you to use the option within the post. Look for pin symbol adjacent to the Smiley when you are writing a post. That option is to be used to attach a C file. I am afraid I won't be able to access baidu.com due to security reasons.

[nimadeCFD]

Dear Vinerm,
I get it. Now I‘ve edited the post and attached the C file. Thank you for your tips.

[vinerm]

That's why it is important to look at the file. You have space before precompiler directives. You cannot use space before #if and #endif. They should start from first column.

[nimadeCFD]

Dear Vinerm,
I modify the UDF code by deleting the space. Unfortunately, the error still exists.



I attach the snipped pictures of the setting of the fluent launch interface for your perusal.
This problem is troublesome for me. Thank you for your constant help.

[vinerm]

I was able to compile it. It appears that you are starting Fluent directly. Instead, start Fluent using command from the Developer command prompt of VS. Go to Start and then search for Developer command prompt. Start Fluent from there and then compile.

[nimadeCFD]

Dear Vinerm,
I opened the VS 2010, and click the ->file->new project->search' Developer command prompt'. But it shows this item doesn't exist. Then I open the control panel and search whole applications. There isn't developer command prompt app, which means I don't install this app. So is it right that I have to install this and relevant Net. frame?
Thank you.

[nimadeCFD]

Hi Vinerm,
Meanwhile, I interpret and compile a same UDF in a simple 2D model in serial. However, I find the difference, though the UDF can be implemented by two different ways. On other word, the result related to the compiled UDF is wrong. Maybe I need to rebuild the compile environment.

[vinerm]

You do not need to open VS. Just go to Start Menu in Windows and find Developer or x64 or x86 command prompt. This is different from general command prompt.