CONFIDENTIAL Combustion Limits in Fire and Explosion Hazards Geoff Chamberlain and Jonathan Puttock, Major Hazards Management Team, Shell Global solutions UK, Chester.
Early Experiments – G. Kalghatgi, 1981 • Determined the blow out limits for subsonic gases. • Established universal stability curve.
Experiments in crosswinds – lifted flames • Sheffield University wind tunnel at Buxton • Burners 2-20 mm, crosswinds up to 8m/s • Methane, propane, Butagas (propane/butane mix), ethylene • Results non-dimensionalised using the grouping • Flames are less stable when burner tilted away from wind
CONFIDENTIAL The Universal Flame Stability Map
Wake stabilised flames – effect of burner tilt • Burner tilted away from flame, flame is more stable – opposite effect with lifted flames.
Bradley et al – simulation heat release contours MW/m3. Jet mean velocity 20m/s, crosswind 5.5 m/s. 10mm diam.CMC flamelet combustion model. HPCx Daresbury. q q
Bradley et al – simulation heat release contours and velocity vectors close to burner tip. q q q
Flammability Limits – Fuel/air/water vapour system. Flame extinction and oscillatory flames in compartments. q q