Experimental and numerical studies of laminar flame characteristics of ethyl acetate with or without hydrogen addition

Abstract

Hydrogen (H2) is an effective additive to improve the issue of low laminar burning velocity of some biofuels. In order to better understand the laminar burning characteristics of ethyl acetate (EA) with or without H2 addition, experimental investigations of laminar burning characteristics were carried out by using the high-speed Schlieren photography technique in a constant volume combustion chamber. Tests were conducted under various equivalence ratios ranging from 0.5 to 1.4 with an initial temperature of 358 K, an initial pressure of 0.1 MPa and a H2/air proportion of 0%, 4%, 8% and 12% by volume. Laminar burning velocities, together with other parameters such as laminar burning flux, flame thickness, Markstein length and Markstein number, were calculated and discussed. In addition, the experimental data were compared with numerical simulations based on the Dayma model. Results showed that the laminar burning velocity of EA was enhanced with the increase of H2 addition, and the maximum value reached 95.09 cm/s at φ = 0.6 with 12% H2, a value more than twice as fast as that of pure EA (39.3 cm/s). Moreover, H2 was found to extend the lower flammability limit of EA. The laminar burning velocities simulated with the Dayma model agreed well with the experimental results of EA at various H2 additions.