[Moha Sobhi]

Dear all;

Can anyone help me in understanding the main difference(s) between (DEFINE_VR_RATE) & (DEFINE_HET_RXN_RATE) user-defined function types?

[Dri]

Hi there,

One of the main difference is the number of phases involved in your simulation. If you have one phase, then you use DEFINE_VR_RATE, while if you have multiple phases, where there is reaction among phases, then you use DEFINE_HET_RXN_RATE. There could be other differences depending on your simulation, so I encourage you to look at the theory guide and the UDF manual for further description on the macros. They are helpful.

[souza.emer]

Originally Posted by Dri

Hi there,

One of the main difference is the number of phases involved in your simulation. If you have one phase, then you use DEFINE_VR_RATE, while if you have multiple phases, where there is reaction among phases, then you use DEFINE_HET_RXN_RATE. There could be other differences depending on your simulation, so I encourage you to look at the theory guide and the UDF manual for further description on the macros. They are helpful.

But, could am I use the two UDF's?
DEFINE_VR_RATE and DEFINE_HET_RXN_RATE at the same time?

And one more thing, the DEFINE_VR_RATE macro could be used in a heterogeneous reaction environment? Like, the reaction
C + O2 = CO2
Where I used one UDF to modify the Reaction Rate with DEFINE_HET_RXN_RATE, and now I'm having trouble with carbon (C) consumption, it's not lowering =/