How to define variable flux on a wall
 

hello friends,
i have been simulating a flow blockage through a coolant channel of fuel assembly.
i have finished the analysis in 2d as well as 3d with average value of heat flux and results are very close to expected results.
now to achiever further refinement in my results i want to use variable heat flux along the length of channel, is there any way i could enter function of flux or variable flux to the wall in 2d or surface in 3d case????

Why not? The macro
would do the job.

Thank you bro,
i got that option ova there but tell me what is the input file format that fluent will read?
and what is the sequence to define that profile, can you help me with a text format for it?:)

The DEFINE_PROFILE I mentioned is a macro of user defined function. You might have read the part on "profile", while is a file format. Either could be used to achieve what you wanted. The former could be easier and more efficient to implement if you have the analytical expression for the flux. You should consult the manual for the "profile" data format.