ASME paper 79-GT-175 presented the design philosophy upon which the Lucas fan spray fuel injection combustion system for small gas turbines is based. Included were results from a system designed for an aircraft Auxiliary Power Unit (APU) and capable of operating with aviation kerosene, gas oil and marine diesel fuels.
Since the publication of the above paper there has been further development of the system and application of the design to a range of engines.
The present paper reviews the design philosophy for fan spray combustion systems and describes its application to a unit for a Remotely Piloted Vehicle (RPV) engine with combustion loadings greater than five times that of the initial application covered by paper 79-GT-175.
The design concept is described together with results from, (a) flow visualisation, (b) testing at combustion loading (ΛSI) values between 6 and 24 kg/s Pa 1·8m3 over a range of air to fuel ratios from 50/1 to 300/1, and (c) light-ups over a range of conditions from sea level static to 15 km at 1.6 Flight Mach No. with fuel fed to various configurations of fuel injector i.e. all six injectors, three equispaced, three grouped together and one only. The fuel used was mainly aviation kerosene with a check at a 290 kW condition using gas oil.