Preliminary Study on Reduced Chemical Mechanisms for Hydrogen Air Combustion

The combustion of hydrogen with air as a promising method for converting energy into zero-carbon power production and propulsion systems is gaining worldwide appreciation. The complex chemical kinetics involved in the high reactivity and radical-driven nature of hydrogen flames, however, are usually described by detailed mechanisms that include 20–21 elementary reactions and 8–10 species. Such methodologies are also computationally very expensive, and often uneconomical on complex simulations such as computational fluid dynamics (CFD), flames analysis or ignition modelling. Accurate modeling is made possible by reduction chemistry, which is the methodical simplification of chemical reaction pathways with less computational overhead. In this article, a very simple review of the reduction chemistry directed to hydrogen-air ignition systems, the need of reduction chemistry, classification, and step-by-step explanation of the key reduction approaches mentioned in literature, such as skeletal, quasi-steady-state (QSSA), intrinsic low-dimensional manifold (ILDM) based methods, and directed relation graph (DRG) based approaches have been discussed.