Tailoring fuels for a shockless explosion combustor

Abstract

Shockless isochoric explosion has been proposed as an alternative to conventional constant-pressure combustion in gas turbines to improve the thermal efficiency. Fully homogeneous auto-ignition and fast burnout facilitate quasi-isochoric combustion, but the ignition delay times depend on local temperatures and mixture composition. This implies that homogeneous auto-ignition is difficult to achieve in the presence of local inhomogeneities. Therefore, in this study, the ignition delay time, its temperature dependence and the excitation time of the potential fuels are investigated. An automatic optimization technique is used to tailor fuels such that the temperature dependence of ignition delay times is minimized to realize homogeneous isochoric auto-ignition in realistic systems even in the presence of inhomogeneities and also to avoid the formation of detonation waves by considering the kinetic properties. Reaction kinetic mechanisms are developed for the chemical modeling of the relevant fuel species and tailor-made compositions of the fuel mixtures are determined by means of simulation.