Plain Jet Kerosene Injection Into High Temperature, High Pressure Crossflow With And Without Filmer Plate

Kurzfassung

The injection of a plain jet of kerosene Jet A-1 fuel into a crossflow of air was investigated experimentally regarding fuel placement, spray characteristics, and evaporation. The test conditions chosen were a test case relevant to LPP (lean premixed prevaporized combustion) for gas turbines (pair=15.5bar, Tair=750K) and the corresponding cold test condition in terms of air density (pair=6bar, Tair=290K). Both test cases were investigated in the absence as well as in the presence of a filmer plate on which part of the nascent fuel spray impinges. The nozzle diameter was 0.45mm and the fuel flowrate was 2.94g/s, so that the fuel-to-air momentum flux ratio q (q=(rliq*uliq2)/(rair*uair2)) assumed a value of 6. Measurement techniques employed include time-resolved shadowgraphs and Phase-Doppler-Anemometry (PDA). In the absence of the filmer plate, spray penetration is noticeably lower at the hot test condition than at the cold test condition. The presence of the plate causes the placement of the fuel to be better defined regardless of test case. Film formation on the plate and evidence of some sort of reflection of the fuel by the plate (e.g. splashing) were observed at both test conditions. At the cold test condition, the filmer plate leads to an overall finer spray. At the hot test condition, however, the plate does not generate a finer spray or accelerate evaporation, which is about 70% complete at a location 80mm downstream from the point of injection.