Analysis of entropy generation in hydrogen-enriched ultra-lean counter-flow methane–air non-premixed combustion

In this paper, entropy generation in hydrogen-enriched ultra-lean counter-flow methane–air non-premixed combustion confined by planar opposing jets is investigated for the first time. The effects of the effective equivalence ratio and the volume percentage of hydrogen in fuel blends on entropy generation are studied by numerically evaluating the entropy generation equation. The lattice Boltzmann model proposed in our previous work, instead of traditional numerical methods, is used to solve the governing equations for combustion process. Through the present study, five interesting features of this kind of combustion, which are quite different from that reported in previous literature on entropy generation analysis for hydrogen-enriched methane–air combustion, are revealed. The total entropy generation number can be approximated as a linear increasing function of the volume percentage of hydrogen in fuel mixture and the effective equivalence ratio for all the cases under the present study.