Lift Force
Use the Lift Force node to exert a lift force on particles in a fluid. Lift forces are applicable when particles move through a fluid in which the velocity field is nonuniform.
Supported formulations:
LIFT Force
Select a Lift law: Saffman (the default) or Wall induced.
Saffman and Wall induced lift forces are applicable for particles traveling through a creeping flow. The Saffman lift force is applicable for particles far from walls. The Wall induced lift force is a specialized formulation to account for the effects of nearby walls as particles move through pipes or channels.
In 3D models, using the Wall induced lift force can cause a significant increase in computation time, due to the additional overhead of locating the nearest point on a wall for each particle at every time step. This is most noticeable if the boundary mesh is very fine.
Enter coordinates for the Velocity field u (SI unit: m/s) based on space dimension. If another physics interface is present which computes the velocity field then this can be selected from the list.
The Dynamic viscosity μ (SI unit: Pa·s) is taken From material. For User defined enter another value or expression.
If Saffman is selected from the Lift law list it is only necessary to specify the set of domains in which the lift force is exerted. If Wall induced is selected, the Parallel Boundary 1 and Parallel Boundary 2 selections are also shown. These two boundary selections are typically two parallel surfaces on either side of a parabolic flow profile.
Wall Corrections
This section is shown when Wall induced is selected from the Lift law list. The settings are the same as for the Drag Force node.