Laminar Flame Velocity and Temperature Exponent of Diluted DME-Air Mixture

[摘要] In this paper, the laminar flame velocity and temperature exponent diluted dimethyl ether (DME) air mixtures are reported. Laminar premixed mixture of DME-air with volumetric dilutions of carbon dioxides (CO2) and nitrogen (N2) are considered. Experiments were conducted using a preheated mesoscale high aspect-ratio diverging channel with inlet dimensions of 25 mm 2 mm. In this method, flame velocities are extracted from planar flames that were stabilized near adiabatic conditions inside the channel. The flame velocities are then plotted against the ratio of mixture temperature and the initial reference temperature. A non-linear power law regression is observed suitable. This regression analysis gives the laminar flame velocity at the initial reference temperature and temperature exponent. Decrease in the laminar flame velocity and increase in temperature exponent is observed for CO2and N2diluted mixtures. The addition of CO2has profound influence when compared to N2addition on both flame velocity and temperature exponent. Numerical prediction of the similar mixture using a detailed reaction mechanism is obtained. The computational mechanism predicts higher magnitudes for laminar flame velocity and smaller magnitudes of temperature exponent compared to experimental data.

[发布机构] Department of Aeronautical Engineering, King Abdulaziz University, Jeddah, Saudi Arabia^1

[效力级别] 航空航天工程 [学科分类] 航空航天科学

[关键词] Adiabatic conditions;Detailed reaction mechanisms;High aspect ratio;Laminar flame velocity;Non-linear power law;Numerical predictions;Ratio of mixture;Reference temperature