Laminar combustion characteristics of ethyl acetate/hydrogen/air at elevated pressures

Ethyl acetate/hydrogen/air (EA/H-2 /air) premixed flame combustion characteristics were investigated at the initial pressures of 1 bar, 2 bar, and 3 bar and a temperature of 358 K using H-2 in air volumetric fractions of 0 %, 4 %, 8 %, and 12 %. Specifically, the laminar burning speed (LBS) and intrinsic flame instabilities of the EA/H-2/ air premixed flames were investigated. The laminar burning speed follows the order of 0 % < 4 % < 8 % < 12 %. The maximum laminar burning speeds of 0.85 m/s, 0.78 m/s, and 0.70 m/s were measured at the initial pressures of 1, 2, and 3 bar, respectively, when a 12 % concentration of hydrogen was added to EA. Reactions R98: H + O-2 double left right arrow O + OH and R136: CH3 + H (+M) double left right arrow CH4 (+M) significantly promoted and inhibited EA/H-2/air LBS, respectively. Furthermore, the decreased flame thickness or curvature effect mainly caused the instability and cellularity of the EA/H-2/air premixed flames when the concentration of hydrogen and the initial pressure increased. Theoretically, EA/H-2/air premixed flames were thermal-diffusively stable and hydrodynamically unstable. This study provides a profound understanding of the combustion characteristics of EA/H-2/air relevant to its application in combustors.

Automated summary

This study investigated the combustion characteristics of ethyl acetate/hydrogen/air premixed flames. It was found that the laminar burning speed increased significantly with the addition of hydrogen. Furthermore, an increase in hydrogen concentration and initial pressure led to flame thinning and curvature effects, causing flame instability and cellularity.