[guanql88]

hi,

I am confused about the particle reaction rate UDF “DEFINE_PR_RATE
". In the fluent udf manul it says: "Note that a DEFINE_PR_RATE UDF is not called with the coupled solution option, so you will need to disable the Coupled Heat Mass Solution option in the Discrete Phase Model panel when using it"

but if the fluid and particle simulations were not coupled, how can I get the correct results?

[vasava]

I think here coupling has something to do with the coupling of the differential equations and not the coupling of the solvers.

[guanql88]

Thank you, I have found this in Fluent help: “By default, the solution of the particle heat and mass equations are solved in a segregated manner. If you enable the Coupled Heat-Mass Solution option, FLUENT will solve this pair of equations using a stiff, coupled ODE solver with error tolerance control. The increased accuracy, however, comes at the expense of increased computational expense.”

Originally Posted by vasava

I think here coupling has something to do with the coupling of the differential equations and not the coupling of the solvers.