Wall Conditions (Particle Study)
Procedure
- Right-click the Wall Conditions
item under Particle
Study in the analysis tree and select Insert Wall Condition to
customize the wall boundary condition for a specific wall. - Under Selection,
select model faces or surfaces on which you intend to specify the boundary
condition (see “Selection List” for details).
The selected faces and components appear in the Faces
list.You can also select components. If you want to split the selected components into faces, select the desired components in the selection list and click List All Component Faces
(see “Selection List” for details). - Under Condition, select the
appropriate type of wall boundary conditions and specify the corresponding
parameters values:
Absorption
. The particles are absorbed by the walls.
This is typical for liquid particles. Ideal reflection
. The particles are reflected from the
walls. This is typical for solid particles. Reflection
. Specify the normal 
and tangential 
restitution coefficients which are the
ratios of the absolute values of the normal and tangential velocity components,
correspondingly, after and before the collision: 
(1) 
(2) Figure 1. Velocity components.
- Under Wall Material
Properties, specify the following parameters:
Density
. The density of the wall material.Erosion Coefficient
. This coefficient can be used as a proportionality
constant if other parameters are specified in a system of units
different from the project system of units. The default value is
2·10-9.Function of Particle Diameter
. Defines how erosion depends on the particle diameter.
The default value is 1.Click Dependency to specify the table dependency on the diameter (see “Dependency” for details).
Function of Impact Angle
. Defines how erosion depends from the particle's impact
angle. The default value is 1.Click Dependency to specify the table dependency on the impact angle (see “Dependency” for details).
Function of relative particle velocity
. Defines how erosion depends on the particle's relative
(with respect the velocity of the wall) velocity. The default value
is 2.6.Click Dependency to specify the table dependency on the relative particle velocity (see “Dependency” for details).
Note:These parameters are available if Erosion option is enable under Physical Features in the Settings dialog (see “Physical Features (Particle Study)” for details).
- Click OK
to
create an injection and close the dialog.
Results
The new wall condition item appears under in the Flow Simulation analysis tree.
To specify the default wall boundary condition right-click Wall Conditions under in the analysis tree and select Default Wall Condition. The Default Wall Condition is applied to all model walls unless it is redefined for a specific wall.