Combustion Characteristic of Flow Through a Low Swirl Injector
An experimental study was carried out in order to provide a better understanding of the combustion characteristics of a low swirl injector (LSI). The swirl vanes angles are respectively 37°, 42° and 50°, and the swirl numbers are varied in a wide range. The fuel gases used in the experiment include propane, methane and methane with hydrogen. The results show: (1) the lean premixed propane, methane, methane with hydrogen and air flow through the LSI can sustain steady combustion at a lower swirl number; (2) the LSIs can generate a blue lift-off “W” type flames surrounding a long yellow pulsating flame and the blue flame consists of four clusters blue flames connected together along circumferential direction; (3) the flame structure converts the “W” type flame into the “broom” type flame with the pulsating yellow flame, and the distance between the front of the flame and the nozzle shortens with increasing swirl number in the same vane angle case; (4) the spectroscopic of the flame shows the yellow flames are emitted by diatomic carbon.