Please do not ask the same question on multiple threads, and please do not re-activate 3-year old threads to ask a new question.
As Justin pointed out, the options are disabled for a reason.
In this case, the GUI is not doing a great job of explaining why the option is disabled. I had to refer to the MFiX specification:
Most of the solids wall BCs are only needed for TFM solids. PIC does not support ANY of the wall BC specifications. DEM only supports keywords associated with the energy equations.
-
Enable Jackson-Johnson partial slip boundary
- Disabled for DEM and PIC solids
- Disabled (0.0) for CARTESIAN_GRID = .TRUE.
- Disabled (0.0) for KT_TYPE = ‘ALGEBRAIC’
- Disabled (0.0) for KT_TYPE = ‘GHD’
- Sets keyword BC_JJ_PS(#)
- DEFAULT 1.0 when not disabled
- Unsets keyword BC_Hw_s(#,#) to UNDEFINED
- Sets keyword BC_Uw_s(#,#) to 0.0
- Sets keyword BC_Vw_s(#,#) to 0.0
- Sets keyword BC_Ww_s(#,#) to 0.0
- Enables wall velocity specification (below)
- Disables transfer coefficient specification (below)