Non-working example in User Guide

[mst-parkhachev]

Dear developers!

A minor inaccuracy was discovered in FDS User Guide 6.9.1. The code example in section "13.2.1 Balancing the Atoms" produces an error "Problem with REAC 1. Unbalanced stoichiometry."

&SPEC ID='NITROGEN', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='OXYGEN', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='WATER VAPOR', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='CARBON DIOXIDE', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='METHANE' /
&SPEC ID='AIR', BACKGROUND=T,
SPEC_ID(1)='OXYGEN', VOLUME_FRACTION(1)=0.2076,
SPEC_ID(2)='NITROGEN', VOLUME_FRACTION(2)=0.7825,
SPEC_ID(3)='WATER VAPOR', VOLUME_FRACTION(3)=0.0095,
SPEC_ID(4)='CARBON DIOXIDE', VOLUME_FRACTION(4)=0.0004 /
&SPEC ID='PRODUCTS',
SPEC_ID(1)='CARBON DIOXIDE', VOLUME_FRACTION(1)=0.0944,
SPEC_ID(2)='WATER VAPOR', VOLUME_FRACTION(2)=0.1966,
SPEC_ID(3)='NITROGEN', VOLUME_FRACTION(3)=0.7090 /
&REAC FUEL='METHANE', SPEC_ID_NU='METHANE','AIR','PRODUCTS',
NU=-1,-9.636,10.636, HEAT_OF_COMBUSTION=50000. /

test_01.txt

[drjfloyd]

Thanks we will take a look.

[drjfloyd]

We must have tweaked the default REAC_ATOM_ERROR and not double checked the example. I will push up a fix,

[drjfloyd]

&SPEC ID='NITROGEN', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='OXYGEN', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='WATER VAPOR', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='CARBON DIOXIDE', LUMPED_COMPONENT_ONLY=T /
&SPEC ID='METHANE' /

&SPEC ID='AIR', BACKGROUND=T,
SPEC_ID(1)='OXYGEN', VOLUME_FRACTION(1)=0.20756,
SPEC_ID(2)='NITROGEN', VOLUME_FRACTION(2)=0.78257,
SPEC_ID(3)='WATER VAPOR', VOLUME_FRACTION(3)=0.00948,
SPEC_ID(4)='CARBON DIOXIDE', VOLUME_FRACTION(4)=0.00039 /

&SPEC ID='PRODUCTS',
SPEC_ID(1)='CARBON DIOXIDE', VOLUME_FRACTION(1)=0.09438,
SPEC_ID(2)='WATER VAPOR', VOLUME_FRACTION(2)=0.19663,
SPEC_ID(3)='NITROGEN', VOLUME_FRACTION(3)=0.70899 /

&REAC FUEL='METHANE', SPEC_ID_NU='METHANE','AIR','PRODUCTS',
NU=-1,-9.6357,10.6357, HEAT_OF_COMBUSTION=50000. /

[mst-parkhachev]

Thank You, dr. Floyd!