Evaluation of the surrogates capacity to reproduce the laminar burning velocities and the sensitivity to stretching of a commercial kerosene under constant volume combustion conditions

These last years, aircraft manufacturers and environmental international bodies have set drastic targets concerning turbo-engines pollution and consumption reduction. To reach the objectives of pollutant emission and consumption reductions, innovative solutions such as constant-volume combustion are in development. Characterizing the propagation of a kerosene-air flame in this kind of combustion is necessary. Particularly, the knowledge of fundamental properties like the laminar burning velocity in laminar adiabatic conditions can be useful for the design of efficient innovative turbo-engines. A new spherical combustion chamber developed in Institut PPRIME and the associated post-processing procedure are first validated using a n-decane/air premixed flame, and a good agreement is obtained with the literature. Measurements of laminar burning velocities and Markstein lengths of commercial kerosene/air mixture and kerosene surrogates/air are then performed at various temperatures (T-0 = 400 K to 470 K), pressures (P-0 = 0.1 MPa to 0.5 MPa) and equivalence ratios (Phi = 0.6 to 1.5). Two mono-component surrogates are tested as a representative of commercial kerosene (n-decane and n-dodecane), with two multi-component surrogates: the Dagaut surrogate (n-decane/n-propylbenzene/n-propylcyclohexane) and the MURI2 surrogate (n-dodecane/iso-octane/1,3,5-trimethylbenzene/n-propylbenzene). Additionally, numerical simulations of laminar burning velocities are performed using JetSurF 2.0 and the Luche reduced chemical kinetic mechanism, representing respectively mono-component surrogates and the Luche surrogate. They are able to represent correctly the experimental measurements. A comparison of the different employed surrogates with commercial kerosene is also performed to evaluate the ability of these surrogates to reproduce the laminar burning velocity properties of the commercial kerosene.

Automated summary

In recent years, aircraft manufacturers and international environmental organizations have established strict objectives for reducing pollution and fuel consumption in turbo-engines. Innovative solutions like constant-volume combustion are being developed to meet these goals. Experimental measurements and numerical simulations with different surrogates for commercial kerosene are conducted to evaluate their ability to reproduce the laminar burning velocity properties of commercial kerosene.