hello every one:

my question is: I want to simulate the changes of oxygen concention in the microbiogranules. The granules are in water,oxygen transfers from water to it.The reactions take place in the surface and inside of the granules are very complex.But i just want to describe this progress in a simple way.But i have no good idea in it.And first of all,i don't know how to set the react conditions in fluent code.I need your help,thanks!

check the species transport model. if it doesnt work, u have to write UDF.