23.2 Steps for Using the Discrete Phase Models

You can include a discrete phase in your ANSYS FLUENT model by defining the initial position, velocity, size, and temperature of individual particles. These initial conditions, along with your inputs defining the physical properties of the discrete phase, are used to initiate trajectory and heat/mass transfer calculations. The trajectory and heat/mass transfer calculations are based on the force balance on the particle and on the convective/radiative heat and mass transfer from the particle, using the local continuous phase conditions as the particle moves through the flow. The predicted trajectories and the associated heat and mass transfer can be viewed graphically and/or alphanumerically.

The procedure for setting up and solving a problem involving a discrete phase is outlined below, and described in detail in Sections  23.2.1- 23.7. Only the steps related specifically to discrete phase modeling are shown here. For information about inputs related to other models that you are using in conjunction with the discrete phase models, see the appropriate sections for those models.

1.   Enable any of the discrete phase modeling options, if relevant, as described in Section  23.2.1.

2.   Choose a transient or steady treatment of particles as described in
Section  23.2.2.

3.   Specify tracking parameters and select a drag law as described in Section  23.2.3.

4.   Enable the required physical submodels for the discrete phase model, as described in Section  23.2.5.

5.   Set the numerics parameters and solve the problem, as described in Section  23.2.8 and Section  23.6.

6.   Specify the initial conditions and particle size distributions in injections, as described in Section  23.3.

7.   Define the boundary conditions, as described in Section  23.4.

8.   Define the material properties, as described in Section  23.5.

9.   Initialize the flow field.

10.   Solve the coupled or uncoupled flow (Section  23.6).

11.   For transient cases, advance the solution in time by taking the desired number of time steps. Particle positions will be updated as the solution advances in time. If you are solving an uncoupled flow, the particle position will be updated at the end of each time step. For a coupled calculation, the positions are iterated on or within each time step.

12.   Examine the results, as described in Section  23.7.