• hydrogen
• combustion
• chemiluminescence
• micro-Gas Turbines

In the next years, the world will face a green transition aimed at reducing the carbon footprint and pollutant emissions. This means replacing fossil fuels with renewable energy sources used directly where applicable, or burning synthetic fuels, such as green hydrogen and ammonia. Therefore, the development of high efficiency combustion technologies, capable of working under different fuel and load conditions, is required. In this regard, micro-Gas Turbines (mGTs) has drawn attention thanks to their low costs and high fuel flexibility, despite they still present relatively low efficiency compared to traditional gas turbines.
The aim of this thesis is to analyse the non-premixed combustion of several mixtures of methane and hydrogen (in different proportions) for fuel-flexible mGT applications, with the final goal of improving the operation of such combustion systems and providing a starting point for their optimization.
For this purpose, a lab-scale mGT burner, developed by Walloon SME MITIS and Université Libre de Bruxelles (ULB), was taken as a reference and two experimental campaigns were carried out; one by preheating the air at 650 °C and the other without.
To analyse flame characteristics, an optical diagnostic technique based on OH* and CH* chemiluminescence was applied, by using high-speed cameras and filters. Indeed, in previous works, OH* and CH* chemiluminescence intensities have been widely employed as a flame front marker and indicators of heat release and equivalence ratio. In the first experimental campaign, data on the exhaust gas emissions were also collected.