Wall Types and Options
By default, the wall is defined to be no slip. For such cases, the fluid adjacent to the wall moves at the same speed as the wall. The following options are available:
| Free slip | The motion of the wall does not impact the flow. Typically used to represent the extent of the fluid region adjacent to a frictionless wall. |
| Stationary | The wall is not moving or rotating. This option is available with No slip walls. |
| Rotating | The wall is rotating and specify its rotational speed This option is available with No slip walls. |
| Translating | The wall is moving in a translational direction. Specify its velocity. The direction of motion for the translating wall must be tangential to the face. This option is available with No slip walls. |
| Thermal condition | Thermal conditions at the extremity of the fluid flow. See Thermal Conditions for Walls for details. |
| Internal radiation | Internal radiation is used to model surface-to-surface radiation heat transfer within the fluid region. See Internal Radiation for more information. |
| Internal emissivity | Internal emissivity is the measure of a material's ability to emit heat by radiation from within itself, or from a surface that is surrounded by the same material. It is a dimensionless quantity that ranges from 0 to 1. A value of 0 means radiation is reflected and 1 means radiation is absorbed. Blackbody surfaces have an emissivity of 1. |
| External emissivity | External emissivity is the measure of a material's ability to emit heat by radiation to its surroundings, or to receive radiative heat from its surroundings. It is a dimensionless quantity that ranges from 0 to 1. A value of 0 means radiation is reflected and 1 means radiation is absorbed. Blackbody surfaces have an emissivity of 1. |