Structure and Emission Characteristics of n-Heptane-Air Flames

Partially premixed flames are formed by mixing air (in less than stoichiometric amounts) into the fuel stream prior to the reaction zone, where additional air is available for complete combustion. Our previous work in this area has focused on partially premixed flames burning methane fuel. The objective now is to extend this work to flames involving higher hydrocarbon (liquid) fuels relevant to diesel engine and gas turbine combustors.

The overall objective is to investigate strategies, based on controlling the level of partial premixing, for simultaneously reducing pollutants emissions and improving flame stability. We are currently using simulations and measurements of n-heptane partially premixed flames in both counterflow and coflow configurations. Detailed results have been obtained pertaining to the structure, extinction, and NO emission behavior of counterflow flames.