The Phenomenon of Knocking: An Extension of Ricardo's Theory that Removes a Contradiction and Provides an Explanation

RECENT researches by Withrow and Boyd (reference 1) and by Schnauffer (reference 2) each using a different technique, have shown that the phenomenon of knocking is accompanied by an apparently simultaneous reaction of the last part of the charge to burn. Whether the reaction of this part of the charge is actually simultaneous or whether the reaction zone travels with a very high velocity, has not yet been determined. In any case, it will be conceded that the progress of the reaction zone is too rapid to be dependent upon the transfer of heat energy by conduction from the flame front as in normal combustion. In the light of these researches and others, some of which have been carried out in the Aeronautical Engine Laboratory of the Massachusetts Institute of Technology, I believe it is possible to postulate a very simple and reasonable theory of knocking, which fulfils all present requirements and which may in some degree help to remove the veil of mystery which has surrounded the subject.