Combustion Science and Technology, Vol.176, No.3, 359-379, 2004
Flame stability with elliptical nozzles in a crossflow
A subscaled flaring system was set up to investigate the effects of elliptical nozzles on flame stabilities of flares in a crossflow for a range of operating conditions. The work presents the experimental results of natural gas flames issuing from circular and different aspect ratios (major/minor axis) elliptical nozzles with discharge areas of 16.4, 30.4, and 93.7 mm(2). It is found that flames issuing from elliptical nozzles with major axis perpendicular to the crossflow have wider stability limits compared with flames issuing from a circular nozzle or elliptical nozzles-with minor axis normal to the crossflow. This is due to the larger recirculation zone on the lee side of the flare stack. However, the fuel-air mixing process is a very complex mechanism due to counter-rotating vortices, axis-switching, and crossflow conditions.