Using Ansys Fluent’s discrete phase modeling capability, reacting particles or droplets can be modeled and their impact on the continuous phase can be examined. Several heat and mass transfer relationships, termed "laws", are available in Ansys Fluent and the physical models employed in these laws are described in this section.
The laws that you activate depend upon the particle type that you select. In the Set Injection Properties Dialog Box you will specify the Particle Type, and Ansys Fluent will use a given set of heat and mass transfer laws for the chosen type. All particle types have predefined sequences of physical laws as shown in the table below:
| Particle Type | Description | Laws Activated |
|---|---|---|
| Massless | – | – |
| Inert | inert/heating or cooling | 1, 6 |
| Droplet | heating/evaporation/boiling | 1, 2, 3, 6 |
| Combusting | heating; evolution of volatiles/swelling; heterogeneous surface reaction | 1, 4, 5, 6 |
| Multicomponent | multicomponent droplets/particles | 7 |
In addition to the above laws, you can define your own laws using a user-defined function. More information about user-defined functions can be found in the Fluent Customization Manual.
You can also extend combusting particles to include an evaporating/boiling material by selecting Wet Combustion in the Set Injection Properties Dialog Box.
Ansys Fluent’s physical laws (Laws 1 through 6), which describe the heat and mass transfer conditions listed in this table, are explained in detail in the sections that follow.