Preknock Vibrations in a Spark-Ignition Engine Cylinder as Revealed by High-Speed Photography
- Author:
- Logan, Walter O , Jr
- Published:
- January 1944.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Miller, Cearcy D
Online Version
- hdl.handle.net , Connect to this object online.
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available.
Free-to-read Unrestricted online access - Summary:
- The high-speed photographic investigation of the mechanics of spark-ignition engine knock recorded in three previous reports has been extended with use of the NACA high-speed camera and combustion apparatus with a piezoelectric pressure pickup in the combustion chamber. The motion pictures of knocking combustion were taken at the rate of 40,000 frames per second. Existence of the preknock vibrations in the engine cylinder suggested in Technical Report no.727 has been definitely proved and the vibrations have been analyzed both in the high-speed motion pictures and the pressure traces. Data are also included to show that the preknock vibrations do not progressively build up to cause knock. The effect of tetraethyl lead on the preknock vibrations has been studied and results of the tests are presented. Photographs are presented which in some cases clearly show evidence of autoignition in the end zone a considerable length of time before knock occurs.
- Collection:
- NASA Technical Reports Server (NTRS) Collection.
- Note:
- Document ID: 19930091864.
Accession ID: 93R21154.
NACA-TR-785. - Terms of Use and Reproduction:
- No Copyright.
View MARC record | catkey: 15426876