Combustion Phenomena of High Temperature Air Combustion - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 83

2000

1800

1600

T = 1855.4K
T = 75.1K

x = 50 mm
y = 150mm

1400

0 200 400 600 800 1000

Time, ms

(a) Nozzle 2

2000

1800

1600

T = 1685.8K
T = 43.1K

x = 90 mm
y = 150mm 1400

0 200 400 600 800 1000

Time, ms

(b) Nozzle 4

1.0

Nozzle 2

T = 1855.4K
T = 75.1K

0.8

x = 50 mm
y = 150mm

0.6

Nozzle 4

0.4

T = 1685.8K
T = 43.1K

0.2

x = 90 mm
y = 150mm

0

1400 1600 1800 2000

Temperature, K

(c) Cumulative frequency distribution of temperature fluctuations

FIGURE 2.57 Temperature fluctuations at the maximum time-averaged temperature and their
cumulative frequency distribution.

essential in advanced low NO x technology, but is not applicable for low temperature
air combustion.

2.3.3.2 Unmixedness

Local characteristics of a flame are dominated by the nature of turbulence in turbulent
combustion, and so it is in furnaces because the flow regime in industrial furnaces
is usually turbulent. Fluctuations in velocity, temperature, and concentration are