Change of behavior in burner surface

[marcosvanella]

I'm picking up a change in behavior for a burner made of a MULT line of obstacles. Input file:

HEAD CHID='test_1mesh', TITLE='0.0385 kg/m2s Propene, 1.0 cm res.' /
&TIME T_END=1. /
&MESH IJK=54,54,54, XB=-0.27,0.27,-0.27,0.27, -0.04,0.5 /
&REAC FUEL       = 'PROPYLENE'
      FYI        = 'Propylene, C_3 H_6'
      SOOT_YIELD = 0.07 /

&SLCF PBY=0.001, QUANTITY='TEMPERATURE', CELL_CENTERED=.TRUE. /
&BNDF QUANTITY='WALL TEMPERATURE' /

&MATL ID='STEEL', CONDUCTIVITY=54, DENSITY=7800, SPECIFIC_HEAT=0.465, EMISSIVITY=0.8 /
&SURF ID='PAN', COLOR='GRAY 50', MATL_ID='STEEL', THICKNESS=0.003/
&SURF ID='POOL', COLOR='LIGHT BLUE', SPEC_ID='PROPYLENE', MASS_FLUX=0.0385, TMP_FRONT=140 / !(kg/m2-s) 
!0.302 g/s ~13.1kW with FDS computed Heat of Comb of 43.411kJ/g in 10 cm burner

&VENT MB='ZMIN', SURF_ID='OPEN' /
&VENT MB='ZMAX', SURF_ID='OPEN' /
&VENT MB='YMIN', SURF_ID='OPEN' /
&VENT MB='YMAX', SURF_ID='OPEN' /
&VENT MB='XMIN', SURF_ID='OPEN' /
&VENT MB='XMAX', SURF_ID='OPEN' /

! Defining Burner (10 cm diameter -> 0.00785 m2)
&VENT XB=-0.05,0.05,-0.05,0.05,-0.02,-0.02, XYZ=0.,0.,-0.02,  RADIUS=0.05, SURF_ID='POOL' /
&MULT ID='cube array', DX=0.005,DY=0.005,DZ=0.005, I_UPPER=23,J_UPPER=23,K_UPPER=7/
&OBST XB=-0.06,-0.055,-0.06,-0.055,-.04,-0.035
MULT_ID='cube array'
SURF_ID='PAN'
SHAPE='CYLINDER'
RADIUS=0.05
HEIGHT=0.02
XYZ=0,0,-0.04
ORIENTATION=0,0,1 /

&TAIL /

With the c93b42 repo version of Dec 20th I see this:

whereas with the latest source I see this:

Seems only one wall cell is lighting up in the latter.
I'll bisect this to see where things changed.

[marcosvanella]

@mcgratta the change is related to commit 3045b6 (PR #13977) from January 3. Looks like now only one wall cell in the vent area is assigned the fuel mas flux prescribed. Seems it is the first one in a loop somewhere (lower I, lower J). This is what I see with the line:

&SLCF PBY=-0.041, QUANTITY='MASS FRACTION', SPEC_ID='PROPYLENE', CELL_CENTERED=.TRUE. /

[mcgratta]

OK, I will fix.

[mcgratta]

Should work now. Test and close.

[marcosvanella]

Works, thanks.