Study of Extinction and Ignition Characteristics for Oxygenated Fuels in Nonuniform Flows

Abstract

Experimental studies are carried out for oxygenated and hydrocarbon fuels flames using counterflow flame configurations. Oxygenated fuels include DME, ethanol, and butanol, and hydrocarbon fuels include propane, n-heptane, and iso-octane. A comparative study has been conducted to investigate the extinction, autoignition of all fuels. Studies on nonpremixed flames for extinction and autoignition measurements are carried out by injecting a fuel stream made up of fuel and nitrogen from one duct and an oxidizer stream made up of oxygen and nitrogen from the other duct. In the premixed flame configuration, the strain rate at extinction is measured over a wide range of equivalence ratio and oxygen concentration by injecting the premixed-reactant stream from one duct and nitrogen from the other duct. Numerical calculations are also performed for oxygenated fuels using detailed chemistry at conditions corresponding to those used in the experiments to validate chemical kinetics.