Hi Robert, many thanks for your reply, and appologies that I didn't respond to your answer asap (in the old forum, once I received a reply, I will receive an email...it seems that this feature is not available in the new forum).

Regarding the export options, I will check that. But the idea is that I am planning to export the node temperature in a certain thread with specific sequencing every time step. That's the reason why I would like to use UDF to export, but it seems that the function Node_Function_Values(d,temperature) is not working for a multiphase model. 

In terms of the multiphase model, I am using VOF model and I would like to export the mixture temperature of the node each timestep.

Again many thanks for your time, and if you have some idea on how to use Node_Function_Values(d,temperature) in a multiphase case, please do let me now. Cheers!