Accession Number:

AD0894644

Title:

Research on Methods of Improving the Combustion Characteristics of Liquid Hydrocarbon Fuels. Volume I. Experimental Determination of Ignition Delay Times in Subsonic Flow Systems. Volume 2. Kinetics Modeling and Supersonic Testing

Descriptive Note:

Final rept. 1 Jan 1969-31 Dec 1971

Corporate Author:

ESSO RESEARCH AND ENGINEERING CO LINDENNJ GOVERNMENT RESEARCH LAB

Report Date:

1972-02-01

Pagination or Media Count:

242.0

Abstract:

The purpose of this program was to determine, analytically and experimentally the extent to which the autoignition delay times of liquid hydrocarbons could be reduced by modification of the molecular structure or through the utilization of homogeneous additives and heterogeneous catalysts. To this end the autoignition delays of a number of different hydrocarbons were determined in three different experimental apparatus a well-stirred reactor, a constant flow subsonic duct and a supersonic detached jet or ducted flow system. At one atmosphere pressure the velocity and temperature of the test devices were varied from subsonic to supersonic and from 300 to 1600 K respectively. No quantitative relationship could be established between the ignition lags measured in the constant flow system and the average residence times determined in the stirred reactor at the blow-out point. However, it is clear that the stirred reactor data more closely describe the total hydrocarbon combustion time than any pseudo ignition lag associated with the hydrocarbon. Of the more than 25 different homogeneous additives tested, the strongest ignition promoters, by far, were found to be the alkyl nitrates and nitrites or nitric oxide and nitrogen dioxide. The presence of a platinum surface on the walls of the combustion chamber reduced the autoignition temperature of various hydrocarbons by 350 K. Fuel blends consisting of 15 volume percent n-propyl nitrate in either H-MCPD or Shelldyne-H were ignited and combusted in a piloted supersonic flow Mach 1.5 over a temperature range of 300 to 1300 K.

Subject Categories:

  • Combustion and Ignition
  • Fuels

Distribution Statement:

APPROVED FOR PUBLIC RELEASE