Gas and liquid fuel injection into an enclosed swirling flow

The use of swirler air for atomization has been tested with direct central propane injection and with direct central kerosene and gas oil injection, and its results have been compared with those for nonswirling flow systems under the same conditions. Direct propane injection results in a major extension of stability limits, by comparison to results for premixing, while with liquid fuel injection the stability limits are generally worse than for premixed fuel and air. This may be due to the action of the centrifugal forces on the liquid droplets in the swirl flow, which results in outer swirl flow vaporization and weaker mixtures in the core recirculation region than would be the case for propane injection. A comparison with nonswirling system performance indicated that all emission levels were higher with swirl for propane.