Penetration—Parcel and Vapor

The Parcel and Vapor Penetration reports return the distance interval that contains a given mass percentage of injected parcels or of vapor arising from injected droplets, measuring from the injection point. In both cases, if the given mass percentage is 90%, the report gives the point with 90% of the mass lying between it and the injection point.

The reports apply to the Solid Cone, Hollow Cone, and Nozzle injectors.

To use the Parcel Penetration report, activate the Material Particle physics model and an unsteady time model. The report only includes mass from the injector it is associated with
To use the Vapor Penetration report, activate an evaporation physics model. The report does not differentiate the components of a multicomponent vapor. It measures the total mass of all components.

The reports measure the distance along the injector axis. In the following diagrams, the injection points are at the top. The reports lay out grids with intervals $Δ z$ along the injection axes. The accumulated mass, progressing along anaxis, is:

m_{a c c u m}^{i} = \sum_{k = 0}^{i} m_{k}

(460)

where:

$m_{i}$ is the amount of mass in the $i$ th interval.
$m_{a c c u m}^{i}$ is the cumulative mass from the injection point to the $i$ th interval.

The penetration distance $z_{X}$ where fraction $X$ of the mass is accumulated is:

z_{X} = i \cdot Δ z + Δ z_{X}

(461)

For parcel penetration: $Δ z_{X} = \min (Δ z, Δ z_{\max}) \cdot \frac{X \cdot m_{t o t a l} - m_{a c c u m}^{i - 1}}{m_{i}}$

For vapor penetration: $Δ z_{X} = Δ z \cdot \frac{X \cdot m_{t o t a l} - m_{a c c u m}^{i - 1}}{m_{i}}$

where:

$Δ z_{\max}$ is the maximum distance parcels penetrate into the $i$ th interval.
$m_{t o t a l}$ is the total accumulated parcel or vapor mass.

The calculation assumes mass is distributed evenly along the axis in the $i$ th interval.

The report can be used with periodic interfaces only if the injector axis does not cross a periodic interface.

Penetration Report Properties


Units	Units that are used for specifying the quantity.
Cut parameter	The mass percentage used for defining the penetration distance. The default value is 0.95.
Grid interval	The spacing for the report grid, controlling output resolution. A finer spacing gives a more exact distance, at a higher computational cost. The default value is 5.0E-4 m.

Penetration Report Expert Properties


Representation	Selects a representation. Additional selections appear as representations that are added to the simulation.
Smooth Values	When this property is activated, the report is calculated using node (interpolated) values of the chosen quantity rather than cell values.