Multiphase Mass transfer UDF issue
 

I am simulating a fixed bed wood gasifier using the Euler-Euler multiphase model. I have 2 het rxns and 2 mass transfer equations to simulate the pyrolysis.

I am able to hook my het_rxn_rate udfs into fluent and converge a solution with these running. However, FLUENT will not run my mass transfer UDFs. They compile, I set up the mass transfer in the phase interaction panel and select my UDF names for the rate, but for some reason when I run the calculation I do not see any residual for the species I am mass transfering to (CO and CO2) and when I get my solution the mass fraction of these species is 0. Also, every time I go back to the phase interaction panel, the rate of the mass transfer is still listed as user defined, but the name of my UDFs is not shown in the box. Is this a problem with the UDF (i.e. the number out is equal to 0, though this seems unlikely since it is a relatively simple UDF) or am i just setting up something incorrectly in the interface?