Knocking combustion observed in a spark-ignition engine with simultaneous direct and Schlieren high-speed motion pictures and pressure records

Osterstrom, Gordon E

Simultaneous direct and Schlieren photographs at 40,000 frames per second and correlated pressure records were taken of knocking combustion in a special spark-ignition engine to ascertain the intensity of certain end-zone reactions previously noted from Schlieren photography alone. A violent propagated homogeneous autoignition, or a similar phenomenon, previously observed, was again observed. The pressure records show autoignition of varying violence before the passage of a probable detonation wave. Extensive autoignition without occurrence of gas vibrations was seen in one explosion.

An Adobe Acrobat (PDF) file of the entire report: