I am trying a validate an analytical work with CFD calculations. Analytical work was carried out for a hyperbolic nozzle where in heat addition and mass addition are considered. Total temperature at inlet=1000 R. Linear variation of total temperature along the length is assumed and is given by the relation 1000+(20*x). Also in the same problem there is mass addition.Mass flow rate at inlet being 100 lb/s, at the exit it is 110 lb/s also varying linearly as 100+x.

Should I write an UDF to do this or are there any other option? Incase UDF is the only option...Can anybody help?

If you haven't done UDFs before, it is not really that straight forward (look at the number of postings on this site on UDF problems).

Have you looked at just using adding a source of mass and enthalpy in your domain. Just name the volume you are interested in, go to boundary condition (yes, I guess it isn't really a boundary), check off source terms and go from there. Sources are added by volume, which may not be linear with x in your case, and you may have to think this part through.

Good luck.

Thanks Allan, I will tryout the things and get back.