Population balance model is nothing but a statistical procedure.

Question his how you are trying to implement it here. Could you please clarify your case.

YES, our group use the population balance to model  formation of nano particles in a supercritical extraction  process. 

complementing the Arafat's answer: the  key issues are the  sources. How are the particles  formed? How is the growth rate? Is there breakage? Agglutination? How many families of sizes is good to consider? These  physics details must be implemented  with a  UDF routines in C. 

Thank you Ricardo.

Arafat: Ricardo pretty much explained what I want to do.

hello can any one help me is possible to use population balance in spray flame combustion where we have first process DPM co convert liquid fuel to vapor after that combustion gas phase and last process is sold formation and grower it . best regards mustafi