Abstract

The emissions produced by aircraft engines give rise to important global environmental concerns like the depletion of the ozone layer and air quality at ground level near airports. Several concepts like RQL (Rich-Burn Quick-Quench Lean-Burn), LPP (Lean Premixed Prevapourised), LDI (Lean Direct Injection) and SC (Staged Combustion) are developed to reduce NOx emissions. These concepts require a high degree of homogeneity and quick mixing of liquid fuel with air in the combustor which depend on the atomisers. The current gas turbine combustors employ airblast atomizers as the primary atomizing devices. The principle advantage of airblast atomizers is their ability to produce a fine spray and quick mixing in the early stages, especially for combustion systems operating at high pressure, comparatively low soot formation and high potential to reduce emissions. For development of airblast atomisers, it is necessary to know their fuel placement characteristics in combustor zone at elevated pressures. The presentation will discuss about basic studies carried out on liquid sheet emerging from prefilming airblast atomizers and characterisation of the spray emerging from the atomisers at elevated pressures and temperatures of air.