Atharva Nagarkar



The C_P macro defines the total pressure and not the partial pressure. There is no separate variable for partial pressure. You can define the partial pressures from total pressure and species mole fraction by taking a product of the two. Mole fraction will need to be defined from the mass fraction and the molecular weight.

Here is an example from the UDF Manual for accessing molecular weights: 2.5. Discrete Phase Model (DPM) DEFINE Macros ( Check section

Here is a link of a similar thread related to partial pressure: Fluent – species – density – UDF (

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