Symmetry

Use the node to define a plane of symmetry at selected boundaries in the geometry.

For particle tracing models, the physical interpretation of plane symmetry is as follows: for every particle that exits the domain through a boundary assigned a node, a new particle enters the modeling domain at the same location at the same time, with an incoming velocity that mirrors the outgoing velocity of the exiting particle. Thus the model particle is specularly reflected as if it hit a Wall with the condition.


	The main advantage of using the Symmetry condition instead of a Wall feature with the Bounce condition is that the Symmetry boundaries are ignored for the purposes of computing the distance and direction of each particle from the nearest wall, which is used for wall induced lift, drag, and turbulent dispersion by the Drag Force and Lift Force features.