Fundamental characterization of alternative fuel effects in continuous combustion systems. Summary technical progress report, 1 February 1980-31 March 1981

Abstract

Recent efforts under this contract have involved (1) investigations of soot production phenomena in gas phase jet-stirred combustors, (2) preliminary experiments concerning the effects of liquid spray fuel injection on soot production in jet-stirred combustors, (3) development and shakedown of ER and E's new Variable Pressure Jet-Stirred Combustor, and (4) continued development of SAI's quasi-global chemical kinetic model of hydrocarbon combustion/soot production processes. Progress in each of these subject areas, including experimental results from the first two areas, detailed descriptions of the Variable Pressure Jet-Stirred Combustor and the present quasi-global model, and brief outlooks on future experimental and modeling efforts are discussed. Results from the gas phase jet-stirred combustor studies provide information regarding a possible soot formation mechanism change at 1800/sup 0/K, the appropriateness of a separate sooting category for 1-methylnaphthalene and other multiring aromatics, the identification of unburned hydrocarbons in the exhaust gases, and the dependencies of soot properties on combustor operating conditions. The liquid fuel spray experiments provide data which relate liquid spray soot yields to fuel type, overall equivalence ratio, atomizing air flow rate, and combustor temperature. Of particular significance is the temperature dependence of the soot yield, which was found to be exactly opposite previous trends obtained in gas phase jet-stirred combustors. The description of the Variable Pressure Jet-Stirred Combustor includes the actual combustor, its versatile air and fuel supply systems, and associated instrumentation and diagnostics. The quasi-global model description contains tentative reaction mechanisms and rate constants and comparisons of model calculations with experimental data.