UDF compiling error

  • Last Post 07 March 2019
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Weiqiang Liu posted this 03 March 2019

hello all,

I am trying to compile a udf I copied from fluent udf manual. My OS is win10 and I am using ansys fluent 18.2. My problem is: no matter what kinds of environmental variable I set or what kind of modification I do to udf.bat file in fluent root path, I always get error like 'the udf library you are trying to load is not compiled for this platform (win 64)'

I can build udf library without any error. This error pops up when I try to load it.

PS: the same udf code on my friend's computer with win7 system does not give any error.

Can anybody tell me how to solve this problem?



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kkanade posted this 04 March 2019

can you please insert an image of your udf. also insert images of your system, errors etc. 

as disclaimer, we dont debug udfs. but if possible we can try to provide correct syntax. 

Max4 posted this 04 March 2019


you can see this discussion: https://studentcommunity.ansys.com/thread/writing-udf-1/


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kkanade posted this 05 March 2019

thanks Max4 for pitching in. 

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Weiqiang Liu posted this 05 March 2019


I installed the matched version of my fluent and it worked finally. Thanks for caring!


Weiqiang Liu posted this 05 March 2019

Hi Max,

I installed the matched version of vs to my fluent version and it finally works.

Thanks very much!


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abenhadj posted this 05 March 2019

Sehr gut Max4, weiter so!

Best regards,


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Weiqiang Liu posted this 07 March 2019

hello, kkanade,

Can I ask you another question under this thread. Actually I am writing UDF to define viscosity and thermal conductivity of mixture varying with temperature. However, with calculation going on, reaction zone moves out of the channel slowly, namely extinction happens. I tried to import chemkin transport data before, also failure of ignition. 

The only way to maintain self-sustaining reaction is to set constant value of viscosity and thermal conductivity. However, results are not very reasonable with constant values. I am very confused why varied viscosity and conductivity would cause failure of ignition.