Flammability Zone Estimator

Indicative hydrogen dispersion zone for leak scenarios - release rate, LFL/UFL cloud dimensions and 2D visualisation.

Flammability Zone Estimator

⚠ Indicative estimates only. These results are for preliminary screening purposes. Use certified CFD or consequence modelling software for formal safety cases, DSEAR assessments and regulatory submissions.
Choked flow assumed for pressures >1.9 bar abs. LFL = 4% vol, UFL = 75% vol. Dispersion modelled as elliptical cloud elongated downwind. Simple Pasquill-Gifford Class D stability assumed.
mm
bar abs
m/s
min

Release & Zone Dimensions

-
H2 Release Rate
kg/s
-
Total H2 Released
kg
-
LFL Zone Radius
m (cross-wind)
-
LFL Downwind Extent
m
-
UFL Zone Radius
m (cross-wind)
-
UFL Downwind Extent
m

Top-Down Dispersion View

Wind direction → right. Red = rich zone (UFL), orange = flammable zone (LFL–UFL). Source at left centre.