{"id":398566,"date":"2024-12-27T02:15:40","date_gmt":"2024-12-27T02:15:40","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ansys-udf-linking-matlab\/"},"modified":"2024-12-27T02:15:40","modified_gmt":"2024-12-27T02:15:40","slug":"ansys-udf-linking-matlab","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ansys-udf-linking-matlab\/","title":{"rendered":"Ansys UDF (Linking MATLAB)"},"content":{"rendered":"

<p>Hi all,<\/p><p>I am working on the 3D-1D coupling of airflow in the airway tree. As such I need to couple my 3D model in Ansys Fluent with my 1D model in MATLAB. The 1D model will serve as my user-defined boundary condition for the 3D model outlets. I have attempted running a sample .c code for my udf but have been unable to get my code to compile. I am using visual studio as my compiler. Under environmental variables, i have added the PATH (C:\\Program Files\\MATLAB\\R2023b\\bin\\win64 and C:\\Program Files\\Microsoft Visual Studio\\2022\\Community\\VC\\Tools\\MSVC\\14.38.33130\\bin\\Hostx64\\x64) , INCLUDE (C:\\Program Files\\MATLAB\\R2023a\\extern\\include), and LIB (C:\\Program Files\\MATLAB\\R2023a\\extern\\lib\\win64\\microsoft) for MATLAB. I believe I have done everything i need to do but I still end up with error messages below. It seems as though the compiler isnt finding the MATLAB LIB although i have specified it under environmental variables. Any help with this would be very much appreciated. I have tried alot of online suggestions and spent two long weeks trying to figure this out and still don’t have a solution.  <\/p><p><span style=”text-decoration: underline;”>Error Message<\/strong><\/span><\/p><p>Copyright 1987-2024 ANSYS, Inc. All Rights Reserved.<\/p><p>Compiler and linker: Microsoft Visual C++<\/p><p># Generating ud_io1.h<\/p><p>Testcode.c<\/p><p># Generating udf_names.c because of makefile Testcode.obj<\/p><p>udf_names.c<\/p><p># Linking libudf.dll because of makefile user_nt.udf udf_names.obj Testcode.obj<\/p><p>Creating library libudf.lib and object libudf.exp<\/p><p>Testcode.obj : error LNK2019: unresolved external symbol engEvalString referenced in function matlab_test<\/p><p>Testcode.obj : error LNK2019: unresolved external symbol engOpen referenced in function matlab_test<\/p><p>Testcode.obj : error LNK2019: unresolved external symbol engClose referenced in function matlab_test<\/p><p>libudf.dll : fatal error LNK1120: 3 unresolved externals<\/p><p>NMAKE : U1077: ‘link -nologo \/Libpath:”C:\\PROGRA~1\\ANSYSI~1\\ANSYSS~1\\v242\\fluent”\\fluent24.2.0\\win64\\3d_node \/Libpath:”C:\\PROGRA~1\\ANSYSI~1\\ANSYSS~1\\v242\\fluent”\\fluent24.2.0\\multiport\\win64\\mpi\\shared \/dll \/out:libudf.dll udf_names.obj Testcode.obj mport.lib fl_mpi2420.lib ‘ : return code ‘0x460′<\/p><p>Stop.<\/p><p><span style=”text-decoration: underline;”>UDF Code<\/span><\/strong><\/p><p>#include “udf.h” \/\/ Fluent UDF header<br>#include “engine.h” \/\/ MATLAB Engine header<br>#include <stdio.h><\/p><p>\/\/ Example UDF using MATLAB Engine<br>DEFINE_EXECUTE_AT_END(matlab_test)<br>{<br>    Engine *ep = engOpen(NULL); \/\/ Open MATLAB engine<br>    if (ep == NULL)<br>    {<br>        Message(“Error: Unable to start MATLAB engine.\\n”);<br>        return;<br>    }<\/p><p>    Message(“MATLAB engine started successfully.\\n”);<\/p><p>    \/\/ Example MATLAB engine command<br>    engEvalString(ep, “disp(‘Hello from MATLAB Engine!’);”);<\/p><p>    engClose(ep); \/\/ Close MATLAB engine<br>    Message(“MATLAB engine closed successfully.\\n”);<br>}<\/p><\/p>\n","protected":false},"template":"","class_list":["post-398566","topic","type-topic","status-publish","hentry","topic-tag-fluent-ansys-1","topic-tag-udf","topic-tag-udferror"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t