UDF for the mixture model

khar nab

Hello the mixture model needs the dispersed phase diameter for the calculation of the slip velocity. I can not understand why this diameter in FLUENT can be integrated using a UDF (variable) while the mixture model employs a constant value. How can a variable diameter affect the mixture model equations. I mean if we suppose that the dispersed phase at a boundary condition is constituted of a particles distributed according to a given law, what would this change in the mixture model calculations and results. I want to know also what is the advantages provided by TGrid.