Subsections

• Rules for PHOENICSpatch regularity
• Boundary Condition Types

BOUNDARY CONDITIONS

  Boundary conditions may be applied to any FEMGEN part or set or parts. The use of these parts and the boundary conditions available are detailed below.

Rules for PHOENICSpatch regularity

 If the topology of the set conforms to the rules outlined in below, the set will be treated as a single patch. If the patch is not regular the patch will be divided into the surfaces or bodies that are in the set.

• A PHOENICSpatch must have a constant number of cells in the I, J, and K directions. A set must also conform to this requirement. If it does not, the interface will produce a patch with I, J, and K values equal to the minimum and maximum I, J, and K values present anywhere in the set.
• If the set is a set of surfaces they must all be in the same I, J, or K plane.
• A patch cannot span blocks.

Boundary Condition Types

The PHOENICS boundary conditions that be can be set in FEMGEN are detailed below.

Inlet

PROPERTY LOADS INLET [load_name] [loadcase_no] part_name phase_number

becomes:-

MPATCH(block_number,BFCpatch_name,area,patch_limits)
COVAL(BFCpatch_name,Pphase_number,FIXFLU,GRND2)
COVAL(BFCpatch_name,UCphase_number,ONLYMS,GRND2)
COVAL(BFCpatch_name,VCphase_number,ONLYMS,GRND2)
COVAL(BFCpatch_name,WCphase_number,ONLYMS,GRND2)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_number - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

Inlet velocity

PROPERTY LOADS INVEL [load_name] [loadcase_no] part_name phase_numb uvel vvel wvel

becomes:-

MPATCH(block_number,BFCpatch_name,area,patch_limits)

If phase_numb is 1

COVAL(BFCpatch_name,UCRT,ONLYMS,uvel)
COVAL(BFCpatch_name,VCRT,ONLYMS,vvel)
COVAL(BFCpatch_name,WCRT,ONLYMS,wvel)

If phase_number is 2

COVAL(BFCpatch_name,UCT2,ONLYMS,uvel)
COVAL(BFCpatch_name,VCT2,ONLYMS,vvel)
COVAL(BFCpatch_name,WCT2,ONLYMS,wvel)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_numb - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

uvel - U velocity

vvel - V velocity

wvel - W velocity

Inlet Temperature

PROPERTY LOADS INTEM [load_name] [loadcase_no] part_name phase_numb temperature

becomes:-

MPATCH(block_number,BFCpatch_name,area,patch_limits)
COVAL(BFCpatch_name,TEMphase_number,ONLYMS,temperature)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_number - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

temperature - inlet temperature

Inlet Turbulent Velocity

PROPERTY LOADS INKEEP [load\_name] [loadcase\_no] part\_name K epsilon

becomes:-

MPATCH(block_number,BFCpatch_name,area,patch_limits)
COVAL(BFCpatch_name,KE,ONLYMS,K)
COVAL(BFCpatch_name,EP,ONLYMS,epsilon)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

area - derived from patch limits

patch_limits - derived from patch location

K - inlet K value

epsilon - inlet epsilon value

Inlet Density

PROPERTY LOADS INDEN [load_name] [loadcase_no] part_name phase_number density

becomes:-

MPATCH(block_number,BFCpatch_name,area,patch_limits)
COVAL(BFCpatch_name,DENphase_number,ONLYMS,density)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_number - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

density - inlet density

Outlet

PROPERTY LOADS OUTLET [load_name] [loadcase_no] part_name phase_numb pressure

becomes:-

MPATCH(block_number,patch_name,area,patch_limits)
COVAL(patch_name,Pphase_numbr,1E3,pressure)
COVAL(patch_name,UCphase_numbr,ONLYMS,0.0)
COVAL(patch_name,VCphase_number,ONLYMS,0.0)
COVAL(patch_name,WCphase_number,ONLYMS,0.0)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_numb - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

pressure - outlet pressure

Outlet Temperature

PROPERTY LOADS OTEM [load_name] [loadcase_no] part_name phase_numb temperature

becomes:-

MPATCH(block_number,patch_name,area,patch_limits)
COVAL(patch_name,TEMphase_numb,ONLYMS,temperature)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_numb - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

temperature - outlet temperature

Outlet Turbulent Velocity

PROPERTY LOADS OKEEP [load_name] [loadcase_no] part_name K epsilon

becomes:-

MPATCH(block_number,patch_name,area,patch_limits)
COVAL(patch_name,KE,ONLYMS,K)
COVAL(patch_name,EP,ONLYMS,epsilon)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_numb - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

K - outlet K value

epsilon - outlet epsilon value

Walls

PROPERTY LOADS WALL [load_name] [loadcase_no] part_name phase_numb

becomes:-

MPATCH(block_number,patch_name,warea,patch_limits)
COVAL(patch_name,UCphase_number,GRND2,0.0)
COVAL(patch_name,VCphase_number,GRND2,0.0)
COVAL(patch_name,WCphase_number,GRND2,0.0)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_numb - 1 or 2

warea - area of WALL derived from patch limits

patch_limits - derived from patch location

Wall temperature

PROPERTY LOADS WALTEM [load_name] [loadcase_no] part_name phase_numb temperature

becomes:-

MPATCH(block_number,patch_name,warea,patch_limits)
COVAL(patch_name,TEMphase_numb,GRND2,temperature)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_numb - 1 or 2

warea - area of WALL derived from patch limits

patch_limits - derived from patch location

temperature - wall temperature

Wall Turbulent Velocity

PROPERTY LOADS WALKEEP [load_name] [loadcase_no] part_name K epsilon

becomes:-

MPATCH(block_number,patch_name,warea,patch_limits)
COVAL(patch_name,KE,GRND2,GRND2)
COVAL(patch_name,EP,GRND2,GRND2)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

warea - area of WALL derived from patch limits

patch_limits - derived from patch location

K - wall K value - ignored but a value must be entered

epsilon - wall epsilon value - ignored but a value must be entered

Temperature

PROPERTY LOADS HEAT [load_name] [loadcase_no] part_name phase_numb temperature

becomes:-

MPATCH(block_number,patch_name,area,patch_limits)
COVAL(patch_name,TEMphase_numb,FIXFLU,temperature)

where:-

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

phase_numb - 1 or 2

area - derived from patch limits

patch_limits - derived from patch location

temperature - temperature

Initial load

PROPERTY LOADS INIT [load_name] [loadcase_no] part_name value

becomes:-

MPATCH(block_number,patch_name,INIVAL,patch_limits)
COVAL(patch_name,load_name,0.0,value)

where:-

load_name - name of the variable to be set

block_name - derived from the patch location

patch_name - name of the patch from loaded part name

patch_limits - derived from patch location

value - value of variable