A Numerical Study on Hydrogen Jet Flame Combustion in MILD Conditions

Abstract

A large degree of dilution and high temperatures are what characterizes MILD (Moderate or Intense Low oxygen Dilution) combustion. This regime is commonly prevailing in FLOX ® systems, where hot gases are recirculated in order to stabilize the combustion process. Current technical developments in the fight against climate change require combustion systems to run with high calorific and at the same time clean fuels, like hydrogen in particular. However, certain difficulties arise in the design process of energy conversion systems with the use of hydrogen. Especially in modeling and simulation, the choice of chemical reaction mechanisms and combustion models is critical. Therefore, in the present study, a jet flame test case is thoroughly investigated, mimicking a combustion situation that is present in FLOX ® based burners. Several reaction schemes and models are tested and results are validated with a large experimental data set. This study features an elaborate investigation of reaction schemes usable in combustor design phases and assesses their applicability in the leaner combustion regime to provide guidance for the design of hydrogen-based combustion systems for energy and aviation applications.