Laminar Burning Velocities of Nitrogen Diluted Standard Gasoline-Air Mixture

To understand how laminar burning velocities of standard unleaded gasoline-air-mixtures change by varying the concentration of oxygen in the combustible mixture, experimentally and numerical investigations are conducted in this work. Experiments were performed using a heatable pressure vessel which enables optical access. A monochromatic high-speed Schlieren cinematography measurement system combined with a high-speed CCD camera were used to track the propagating spherical flame fronts in the vessel.

Numerically, freely propagating one dimensional laminar steady flame calculations were conducted for Primary-Reference-Fuel Air Mixtures (PRF87 or RON87), corresponding for standard gasoline combustible mixtures. Two combustible mixtures were investigated: (1) with air as oxidizer; (2) oxidizer consisting of 15% O₂ and 85% N₂ by mole fractions. The initial temperature for all investigated mixtures was 373 K. Initial pressures were varied from 10 to 25 bar and equivalence ratios were varied from 0.8 to 1.2. Experimental and numerical laminar burning velocities are compared with each other and show an overall good agreement.