NATO STO

a) State-of-the Art. In the document "Petroleum Committee Vision on Future Fuels" developed by the NATO Fuels and Lubricants Working Group (AC/112 [NF&LWG]), a vision for the use of "future fuels" is presented in two scenarios: short-term and long-term [1]. According to the document, in the short-term period (next 10 years), the most practical option is the use of "drop-in fuel" in turbine engines, which involves directly blending synthetic hydrocarbons with conventional aviation fuel. Currently, the ASTM D7566 Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons [2] allows the use of seven synthetic hydrocarbon production technologies in aviation turbine engines, with others being tested and verified. On the other hand, in the long-term perspective (beyond 10 years), one of the future fuels mentioned in the "Petroleum Committee Vision on Future Fuels" document is hydrogen. There are many development efforts in this field, and the utilization of hydrogen in fuel cell systems is already becoming a reality today. b) Research and Methodology At the Air Force Institute of Technology in Warsaw (ITWL), an instrumented combustor rig (Figure 1) based on a micro turbojet engine has been operated for several years. Our research focuses on the application of synthetic hydrocarbon fuels [3]. The conducted engine tests explored the combustion performance of alternative fuels for gas turbines, made in various fuel production technologies. Currently, the research infrastructure is being expanded with a facility equipped with a larger micro turbojet GTM-400 (Figure 2) for conducting tests related to hydrogen co-combustion. This engine was initially designed to be fueled with conventional aviation fuel, while an additional supply line is being built to deliver hydrogen to the engine combustor. A similar model jet engine powered by hydrogen was presented in the publication [4]. The planned tests will involve a comparative analysis of the engine's performance using different proportions of conventional petroleum fuel and hydrogen. The following parameters will be recorded and analyzed: • Basic engine performance parameters, such as thrust, rotational speed and consumption of petroleum fuel and hydrogen. • Emissions of exhaust gases such as CO, CO2, and NOx. In addition, the condition of critical engine components such as the combustor and turbines will be monitored through regular borescope inspections of the GTM-400 engine. University of Salento will be involved in the modelling of the co-combustion in the aeroengine experimentally investigated at ITWL and in experiments of hydrogen co-combustion in a swirled combustor and in the modelling of hydrogen co-combustion. From existing research, the chemical kinetic factors influencing H2 blending in Jet A-1 (aviation fuel) and the chemical reaction process remain unclear. Previous studies have primarily focused on the effects of H2 blending on CH4 explosion and macroscopic characteristics, including combustion features, while the investigation of carbon production characteristics after introducing H2 to Jet A-1-air mixtures has been limited. CO and CO2 serve as the main indices for assessing carbon emissions. To address these knowledge gaps, this project integrated CHEMKIN-PRO 19.0 software and the GRI-Mech 3.0 mechanism to simulate the appearance and disappearance of key elementary reactions affecting carbon production during combustion. It also analyzed changes in key radicals and variations in the molar mass of relevant materials from a chemical kinetics perspective.