23.3.4 Point Properties for Group Injections

For group injections, you will define the properties position, velocity, diameter, temperature, and flow rate for the First Point and Last Point in the group. That is, you will define a range of values, $\phi_1$ through $\phi_N$, for each initial condition $\phi$ by setting values for $\phi_1$ and $\phi_N$. ANSYS FLUENT assigns a value of $\phi$ to the $i$th injection in the group using a linear variation between the first and last values for $\phi$:

Thus, for example, if your group consists of 5 particle streams and you define a range for the initial $x$ location from 0.2 to 0.6 meters, the initial $x$ location of each stream is as follows:

• Stream 1: $x$ = 0.2 meters

• Stream 2: $x$ = 0.3 meters

• Stream 3: $x$ = 0.4 meters

• Stream 4: $x$ = 0.5 meters

• Stream 5: $x$ = 0.6 meters

In general, you should supply a range for only one of the initial conditions in a given group--leaving all other conditions fixed while a single condition varies among the stream numbers of the group. Otherwise you may find, for example, that your simultaneous inputs of a spatial distribution and a size distribution have placed the small droplets at the beginning of the spatial range and the large droplets at the end of the spatial range.

The specified flow rate is defined per particle stream and can also be interpolated using Equation  23.3-1. When a Rosin-Rammler sized distribution is specified the total flow rate will be specified.

For the massless particle type, you will only need to define the first and last point of the injection group position. The particle velocities are set by the solver equal to the velocity of the continuous phase at the injection points.

Note that you can use a different method for defining the size distribution of the particles, as discussed below.