The Mass Flux node can be used to specify the total mass flux of a phase across a boundary. This node is available for surfaces in 3D geometries, edges in 2D and 2D axisymmetric geometries and points in 1D and 1D axisymmetric geometries.

For modeling mass flux from very thin objects add a Line Mass Source or a Point Mass Source node.

The Line Mass Source node adds mass flow originating from a tube of infinitely small radius. It is available for edges in 3D geometries or points in 2D and 2D axisymmetric geometries.

The Point Mass Source node models mass flow originating from an infinitely small sphere centered around a point. It is available for points in 3D geometries.

Specify the inward mass flux for each phase individually. Select the checkbox for the phase to prescribe a mass flux and enter a value or expression for the flux in the corresponding field. To use another boundary condition for a specific phase, click to clear the checkbox for the flux of that phase. Use a positive value for an inward flux. The units are based on the type of node: Mass Flux node: kg/(m2·s), Line Mass Source node: kg/(m·s), and Point Mass Source node: kg/s.