Lean Blowout Detection Techniques for Partially Premixed Flames in a Dump Combustor - Novel Combustion Concepts for Sustainable Energy Development - page 203

(a) (b)

t = 0.10s t = 0.13s

t = 0.03s t = 0.07s t = 0.10s t = 0.13s t = 0.03s t = 0.07s

Fig. 4 Still images of the fl flame at 80 lpm with Δ t = 33-ms intervals away from LBO for a Φ = 1.0

and b Φ = 0.81 L fuel = 35 cm (port 1)

t = 0.03s t = 0.07s t = 0.10s t = 0.13s t = 0.17 t = 0.20s t = 0.23s t = 0.27s

t = 0.30s t = 0.33s t = 0.37s t = 0.40s t = 0.43s t = 0.47s t = 0.50s t = 0.53s

Fig. 5 Still images of precursor event of the flame at 80 lpm with Δ t = 33-ms intervals observed
near LBO, i.e., Φ ≈ Φ LBO = 0.75, L fuel = 35 cm (port 1) (Chaudhari et al. 2013 )

convected back to inlet, which reignites the unburned fuel which entered the com-
bustor in the previous period. The fuel is rapidly consumed which exhibits intense
combustion, and the

flame is re-established in the combustor (reignition event).
These unique extinction and reignition events span a period of several milliseconds,
and they occur randomly in time, prior to LBO. As the combustor approached
toward LBO limit, the frequency of these events increases, and thus, the time
between two such events decreases closer to LBO. Muruganandam et al. ( 2005 )

fl