Technical documentation and software quality assurance for project ...

versus dosage for chemical inhalation. Also there was some discussion on setting ignition
location. Center of cloud seemed to be conservative consensus.
Flare notes
View factor : There was discussion about using a cylindrical optically dense flame, as in
the pool fire model rather than using point source view factor. One recommendation was
to always assume a clear, dry day. This is equivalent to neglecting atmospheric
dampening.
gas exist velocity: Model currently assumes that flame will blow out when Mach number
exceeds 0.5. Suggested that there may be a better number or that this restriction be
dropped (flame could simply start farther away from source). Match rate of combustion
to release rate to achieve steady state case. Most felt that horizontal jets also be allowed
rather than only vertical ones. Model will not work well with oil fires due to smoke
generation.
2-phase: Model currently transforms 2-phase release into gas release. Some pointed out
that 2-phase incident could produce both flare and pool fire. Suggested reviewing
existing references on 2-phase flow to see how to handle for flare situation
BLEVE
fireball size: Experts agreed that limits should be placed upon fireball size. One
suggestion is to limit fireball mass to three times the fraction that is adiabatically flashed.
Another is to restrict user input to largest common propane tank. Compare our simplified
model to results from more sophisticated models.
terminology: Consensus was that careful wordsmithing needs to be done to maintain
consistency of language, technical accuracy, and fit within common usage.
other hazards: Model only considers thermal hazard. People agreed that user should be
warned about all hazards, including overpressure and shrapnel. Some discussion on
shrapnel models
Pool fire
pool size: Model currently stops spreading when the burn rate equals the chemical release
rate. Recommendation was to eliminate this restriction and stop spreading only when
minimum thickness was reached. Need to ascertain upper limit on model applicability for
large fires.
pool shape: Suggested that LOC footprint be circular rather than elliptical in order to be
more conservative.
burn regression rate: Approximation of burn regression rate as ratio of heat of
combustion to heat of vaporization may not be good approximation, particularly for
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