33.7.12 Porous Jump Dialog Box

The Porous Jump dialog box sets the boundary conditions for a porous-jump zone. It is opened from the Boundary Conditions task page. See Section  7.3.20 for details about the items below.

Controls

Zone Name   sets the name of the zone.

Face Permeability   sets the face permeability coefficient ( $\alpha$ in Equation  7.3-69).

Porous Medium Thickness   sets the thickness of the porous medium ( $\Delta m$).

Pressure-Jump Coefficient   sets the pressure-jump coefficient ( $C_2$).

Discrete Phase BC Type   sets the way that the discrete phase behaves with respect to the boundary. This item appears when one or more injections have been defined.

interior   allows the particles to pass through the boundary.

reflect   rebounds the particle off the boundary with a change in its momentum as defined by the coefficient of restitution. (See Figure  23.4.1.)

trap   terminates the trajectory calculations and records the fate of the particle as "trapped''. In the case of evaporating droplets, their entire mass instantaneously passes into the vapor phase and enters the cell adjacent to the boundary. See Figure  23.4.2.

escape   reports the particle as having "escaped'' when it encounters the boundary. Trajectory calculations are terminated. See Figure  23.4.3.

wall-jet   indicates that the direction and velocity of the droplet particles are given by the resulting momentum flux, which is a function of the impingement angle. See Figure  15.6.1TH-dpm-disp-bound-walljet in the separate Theory Guide.

wall-film   consists of four regimes: stick, rebound, spread, and splash, which are based on the impact energy and wall temperature. Detailed information on the wall-film model can be found in this section in the separate Theory Guide. The Number Of Splashed Drops must be specified.

user-defined   specifies a user-defined function to define the discrete phase boundary condition type.

Discrete Phase BC Function   sets the user-defined function from the drop-down list.