This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Some Concepts of Knock and Antiknock Action
Annotation ability available
Sector:
Language:
English
Abstract
RECENT improvements in techniques and instrumentation plus further data on rapid chemical chain reactions have made possible a clearer picture of the chemical reactions in engines. This paper describes the present knowledge of the changes in the fuel-air mixture prior to combustion, the effect of these changes on knock, and the method by which antiknocks function.
Knock is controlled by the preflame reactions occurring prior to fuel combustion. These reactions are very complex, but the specific reactions causing knock seem to be simple, probably involving very fast reactions initiated by combinations of only hydrogen and oxygen. Hydrocarbon structure affects the rate of accumulation of enough of the hydrogen-oxygen species to cause knock.
Tel slows the later stages of reaction, probably by deactivating the hydrogen-oxygen groups. The active antiknock species seem to be either lead oxide or metallic lead.
Recommended Content
Citation
Sturgis, B., "Some Concepts of Knock and Antiknock Action," SAE Technical Paper 550249, 1955, https://doi.org/10.4271/550249.Also In
References
- See SAE Quarterly Transactions Vol. 4 October 1950 571 587 “Precombustion Reactions in a Motored Engine,” Pastell D. L.
- See SAE Quarterly Transactions Vol. 6 July 1952 472 487 “Early Combustion Reactions in Engine Operation,” Rifkin, E. B. Walcutt, and C. Betker, G. W. Jr.
- See SAE Quarterly Transactions Vol. 6 July 1952 488 510 “Some Effects of Fuel Structure, Tetraethyl Lead, and Engine Deposits on Precombustion Reactions in a Firing Engine,” Cornelius and W. Caplan J. D.
- 386 399 “Comparison of Intermediate-Combustion Products Formed in an Engine with and without Ignition, ” Davis, W. C. Smith, M. L. Malmberg E. W. Bobbitt J. A.
- “Combustion of Hydrogen as Related to Knock. I. Parallel Behavior of Hydrogen and Paraffinic Fuels,” Anzilotti, W. F. Scott, G. W. Rogers, and J. D. Tomsic V. J. Presented at 124 th National Meeting of American Chemical Society Chicago Sept. 10 1953
- Philosophical Transactions of the Royal Society of London, Series A Vol. 243 July 19 1951 463 524 “Study of Reactions that Lead to ‘Knock’ in Spark-Ignition Engine,” Downs, D. Walsh, and A. D. Wheeler R. W.
- “Combustion, Flames, and Explosions of Gases,” Lewis and B. von Elbe. G. Academic Press, Inc. New York 1951
- See Journal of Chemical Physics Vol. 15 1947 431 433 “Equilibrium Atom and Free-Radical Concentrations in Carbon Monoxide Flames and Correlation with Burning Velocities,” Tanford and C. Pease R. N.
- “Combustion of Hydrogen and Carbon Monoxide as Related to Knock,” Anzilotti and W. F. Tomsic V. J. Presented at the Fifth International Combustion Symposium Pittsburgh September 1954
- See Industrial and Engineering Chemistry Vol. 46 May 1954 1024 1029 “Preflame Oxidation of Hydrocarbons in a Motored Engine,” Pahnke, A. J. Cohen, and P. M. Sturgis B. M.
- See Industrial and Engineering Chemistry Vol. 43 December 1951 2834 2840 “Correlation of Knock Resistance of Pure Hydrocarbons with Chemical Structure,” Livingston H. K.
- See Journal of the Institute of Petroleum Vol. 38 December 1952 965 973 “Effects of Fuel Additives on Precombustion Reactions of n-Heptane,” Melby A. O.
- See Philosophical Transactions of the Royal Society (London) Vol. 234 1935 434 521 “On the Phenomenon of Knock in Petrol Engines,” Egerton and A. Smith F. L.
- See Proceedings of Royal Society of London Vol. 215 No. 1123 December 1952 454 466 ”Inhibiting Effect of Lead Tetraethyl. Part II. Effect of Lead Monoxide on Slow Oxidation of Methane,“ Hoare and D. E. Walsh A. D.
- See Proceedings of Royal Society of London Vol. 215 No. 1121 November 1952 175 186 ”Inhibiting Effect of Lead Tetraethyl. Part I. Effect of Lead Compounds on Vapor-Phase Slow Oxidation of Diisopropyl Ether and on Ignition of Diethyl Ether,” Chamberlain and G. H. N. Walsh A. D.
- See Pennsylvania State College Technical Bulletin No. 16 April 22 1933 3 20 “Heating Fuels for Injection Engines,” Richardson E. A.
- “Process of Preparing Fuels for Use,” Sept. 6 1932 Richardson E. A.
- 1936 “Influence of Fuel-Oil Temperature on Combustion in a Prechamber Compression-Ignition Engine,” Garrish and H. C. Ayer Bruce E.
- “Introduction to Chemical Physics,” Slater J. C. McGraw-Hill New York 1939