15.3.3 Using the Multiple Surface Reactions Model for Discrete-Phase Particle Combustion

When you use the multiple surface reactions model, the procedure for setting up a problem involving a discrete phase is slightly different from that outlined in Section  23.2. The revised procedure is as follows:

1.   Enable any of the discrete phase modeling options, if relevant, as described in Section  23.2.5.

2.   Specify the initial conditions, as described in Section  23.3.

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

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

You must select multiple-surface-reactions in the Combustion Model drop-down list in the Create/Edit Materials dialog box before you can proceed to the next step.

5.   If you have defined more than one particle surface species, for example, carbon ( C $<$s $>$) and sulfur ( S $<$s $>$), you will need to return to the Set Injection Properties dialog box (or Set Multiple Injection Properties dialog box) to specify the mass fraction of each particle surface specie in the combusting particle. Click the Multiple Reactions tab, and enter the Species Mass Fractions. These mass fractions refer to the combustible fraction of the combusting particle, and should sum to 1. If there is only one surface specie in the mixture material, the mass fraction of that specie will be set to 1, and you will not specify anything under Multiple Surface Reactions.

6.   Set the solution parameters and solve the problem, as described in Section  23.6.

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

Solid deposition reactions on the particle are not allowed together with custom laws.