Effect of Chemical Kinetics and Heat Transfer in the Dynamics of MILD Hydrogen Combustion

This contribution reports about results obtained, both experimentally and numerically, in the dynamic regime of a Jet Stirred Flow Reactor (JSFR) fueled with hydrogen and operated under MILD conditions for operating parameters values at which dynamic regimes occur. It is shown that mixtures of hydrogen and oxygen diluted in nitrogen and argon at different inlet temperatures exhibit a dynamic behavior at a specific range of relatively low inlet temperature, just after the start of the combustion process. Numerical simulations in a non-adiabatic Perfectly Stirred Reactor (PSR), conducted using a new tool for the parametric continuation of detailed chemical mechanisms, are used to verify the ability of present detailed chemical mechanisms of hydrogen combustion to reproduce the observed behavior both in terms of the temperature rise and in the ability to correctly detect the extent of the region of stable dynamic (periodic regime) combustion. Through the comparison of experimental and numerical maps of solutions, current uncertainties still present even for this simple fuel and its oxidation process at low temperature are highlighted.