Laminar Burning Speeds of Nitromethane-Gasoline Blends at Elevated Temperatures and Pressures

Abstract

Nitromethane is extensively used in drag races and in glow plug unmanned aerial vehicle (UAV) engines. However, it has not been analyzed in the combustion literature enough. Nitromethane has a low stoichiometric air–fuel ratio; it can be blended with gasoline and used in larger quantities to enhance the power output of the internal combustion (IC) engines. This could find potential use in burgeoning UAV industry. The present investigation aims at experimentally determining the laminar burning speeds of nitromethane—gasoline blends at different equivalence ratios. Tests were conducted at both ambient conditions and at elevated temperatures and pressures. A constant volume combustion chamber (CVCC) was constructed and instrumented to carry out the investigation. The pressure rise in the chamber due to combustion was acquired and analyzed to determine the laminar burning speeds. The results showed that with an increase in the nitromethane concentration in gasoline, the laminar burning speeds for all the initial conditions also increased. With the rise in initial temperatures, the laminar burning speeds were observed to increase. However, a drop was observed with a rise in the initial pressures for all the blends. The obtained results for pure gasoline were compared with existing literature. A good match was observed. The investigation also aims at providing vital experimental data, which can be used for computational fluid dynamics validation studies later.