Due to the stringent emission requirements for a more sustainable transport, the efforts of the scientific community have gone into research and development of eco-friendly fuels for aeroengines. Water emulsified fuels represents a promising solution. In this regard, the present work provides two main contributions. First, an experimental investigation of the effects of the addition of water into jet-A1 fuel has been carried out on a 300-kW liquid-fueled swirling combustor. Direct measurements of both exhaust temperature and pollutant emissions, defined the diagnostics setup. Several water concentrations have been tested at different fuel/air ratios and under lean conditions, and the impact of each fuel composition has been evaluated on emissions reduction and combustor efficiency. Results pointed out the nitrogen oxides (NOx) reduction in combination with the lowering of the exhaust gas temperature, which coupled with losses in the combustion and in the overall thermal efficiencies. Despite this, the energy losses became negligible when water content in Jet-A1 was limited to 2.5% by mass, which still ensured the benefit in terms of NOx reduction in the measure of about 11% at φ = 0.36 up to 27.4% at φ = 0.18. Further increase of the water content to 5% at fixed φ = 0.36, as well as going to a leaner condition (φ = 0.18) at fixed water content of 2.5%, strongly impacted on the thermal efficiency which reduced to about 25.4% and 41.2%, respectively. Based on the thermal efficiency losses estimated through experimental results, a gas path analysis was performed by implementing a gas turbine model. This allowed to predict the impact of the water addition into Jet-A1 on the performance of the military turbojet Rolls-Royce VIPER 632-43. Both sea level take-off and cruise flight conditions have been analyzed. Numerical predictions confirmed the experimental finding of the NOx reduction in proportion to the reduction of the peak combustion temperature. In addition, the turbojet engine model figured out an increase of the thrust specific fuel consumption (TSFC) of about 6.7% and 22% for 2.5% and 5% of water in Jet-A1 respectively during sea level take-off. Its value rose to 8.0% and 26.7%, respectively, when under cruise conditions. Water addition decreased the engine thrust in proportion to the percent increment of the TSFC.
Effect of jet-A1 emulsified fuel on aero-engine performance and emissions
De Giorgi M. G.
Primo
;Ciccarella G.Secondo
;Ficarella A.;Fontanarosa D.Penultimo
;Pescini E.Ultimo
2019-01-01
Abstract
Due to the stringent emission requirements for a more sustainable transport, the efforts of the scientific community have gone into research and development of eco-friendly fuels for aeroengines. Water emulsified fuels represents a promising solution. In this regard, the present work provides two main contributions. First, an experimental investigation of the effects of the addition of water into jet-A1 fuel has been carried out on a 300-kW liquid-fueled swirling combustor. Direct measurements of both exhaust temperature and pollutant emissions, defined the diagnostics setup. Several water concentrations have been tested at different fuel/air ratios and under lean conditions, and the impact of each fuel composition has been evaluated on emissions reduction and combustor efficiency. Results pointed out the nitrogen oxides (NOx) reduction in combination with the lowering of the exhaust gas temperature, which coupled with losses in the combustion and in the overall thermal efficiencies. Despite this, the energy losses became negligible when water content in Jet-A1 was limited to 2.5% by mass, which still ensured the benefit in terms of NOx reduction in the measure of about 11% at φ = 0.36 up to 27.4% at φ = 0.18. Further increase of the water content to 5% at fixed φ = 0.36, as well as going to a leaner condition (φ = 0.18) at fixed water content of 2.5%, strongly impacted on the thermal efficiency which reduced to about 25.4% and 41.2%, respectively. Based on the thermal efficiency losses estimated through experimental results, a gas path analysis was performed by implementing a gas turbine model. This allowed to predict the impact of the water addition into Jet-A1 on the performance of the military turbojet Rolls-Royce VIPER 632-43. Both sea level take-off and cruise flight conditions have been analyzed. Numerical predictions confirmed the experimental finding of the NOx reduction in proportion to the reduction of the peak combustion temperature. In addition, the turbojet engine model figured out an increase of the thrust specific fuel consumption (TSFC) of about 6.7% and 22% for 2.5% and 5% of water in Jet-A1 respectively during sea level take-off. Its value rose to 8.0% and 26.7%, respectively, when under cruise conditions. Water addition decreased the engine thrust in proportion to the percent increment of the TSFC.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
