- Author
-
Smyth, K. C.
|
Bryner, N. P.
- Title
- Short-Duration Autoignition Temperature Measurements for Hydrocarbon Fuels.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Air Force Engienering and Services Center, Tyndall AFB, FL
- Report
-
NISTIR 4469; ESL-TR-90-43; Session C-5,
December 1990,
47 p.
- Distribution
- Available from National Technical Information Service
- Book or Conf
- Combustion Institute/Eastern States Section. Chemical and Physical Processes in Combustion. Fall Technical Meeting, 1990. December 3-5, 1990,
Orlando, FL,
138/1-4 p.,
1990
- Keywords
-
ASTM E659
|
autoignition temperature
|
engine knock
|
hydrocarbon fuels
|
ignition
|
ignition temperature
|
ignition testing
|
stoichiometry
|
surface ignition
- Abstract
- A new apparatus has been designed, built, and extensively tested for making short-duration autoignition temperature measurements of hydrocarbon fuels under conditions where the fuel/air stoichiometry, the nature of the hot metal surface, and the contact time are well controlled. This approach provides a much more reliable database to establish the importance of fuel structure effects than the current ASTM E659 procedure. Over 1100 individual autoignition temperature determinations have been made for the ignition of 15 hydrocarbon fuels on heated nickel, stainless steel, and titanium surfaces for three different fuel/air mixtures. Excellent reproducibility has been achieved with the new apparatus. The measured autoignition temperatures generally decrease for the larger hydrocarbons and for richer mixtures, with the C2 hydrocarbons (ethane, ethylene, and acetylene) having particularly low values. The highest autoignition temperatures are observed for nickel surfaces and the lowest for stainless steel, with titanium being an intermediate case. A review of the autoignition literature suggests that the branched alkanes should be more resistant to autoignition than the linear isomers, and thus pesent a reduced hazard. Limited data obtained in this study are consistent with this prediction. Promising directions for substantiating these observations and additional areas for future research are outlined.