Relation between spark-ignition engine knock, detonation waves, and autoignition as shown by high-speed photography

One of 1,424 reports in the series: NACA Technical Reports available on this site.

PDF Version Also Available for Download.

Description

A critical review of literature bearing on the autoignition and detonation-wave theories of spark-ignition engine knock and on the nature of gas vibrations associated with combustion and knock results in the conclusion that neither the autoignition theory nor the detonation-wave theory is an adequate explanation of spark-ignition engine knock. A knock theory is proposed, combining the autoignition and detonation-wave theories, which introduces the idea that the detonation wave develops in autoignited or after-burning gases, and ascribes comparatively low-pitched heavy knocks to autoignition but high-pitched pinging knocks to detonation waves with the possibility of combinations of the two types of knocks. ... continued below

Creation Information

Miller, Cearcy D January 1, 1946.

Context

This report is part of the collection entitled: National Advisory Committee for Aeronautics Collection and one other and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 318 times . More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Originator

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Titles

  • Main Title: Relation between spark-ignition engine knock, detonation waves, and autoignition as shown by high-speed photography
  • Series Title: NACA Technical Reports

Description

A critical review of literature bearing on the autoignition and detonation-wave theories of spark-ignition engine knock and on the nature of gas vibrations associated with combustion and knock results in the conclusion that neither the autoignition theory nor the detonation-wave theory is an adequate explanation of spark-ignition engine knock. A knock theory is proposed, combining the autoignition and detonation-wave theories, which introduces the idea that the detonation wave develops in autoignited or after-burning gases, and ascribes comparatively low-pitched heavy knocks to autoignition but high-pitched pinging knocks to detonation waves with the possibility of combinations of the two types of knocks. Analysis of five shots of knocking combustion, taken with the NACA high-speed motion-picture camera at the rate of 40,000 photographs per second reveals propagation speeds ranging from 3250 to more than 5500 feet per second. The range of propagation speeds from 3250 to more than 5500 feet per second is held to be considered with the proposed combined theory but not with either the simple autoignition theory or the simple detonation-wave theory.

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • : 93R21217
  • URL: http://hdl.handle.net/2060/19930091927 External Link
  • Report No.: NACA-TR-855
  • Center for AeroSpace Information Number: 19930091927
  • Archival Resource Key: ark:/67531/metadc60148

Collections

This report is part of the following collections of related materials.

National Advisory Committee for Aeronautics Collection

The National Advisory Committee for Aeronautics (NACA) was a U.S. federal agency founded on March 3, 1915 to undertake, promote, and institutionalize aeronautical research. On October 1, 1958 the agency was dissolved, and its assets and personnel transferred to the newly created National Aeronautics and Space Administration (NASA).

Technical Report Archive and Image Library

This selection of materials from the Technical Report Archive and Image Library (TRAIL) includes hard-to-find reports published by various government agencies. The technical publications contain reports, images, and technical descriptions of research performed for U.S. government agencies. Topics range from mining, desalination, and radiation to broader physics, biology, and chemistry studies. Some reports include maps, foldouts, blueprints, and other oversize materials.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • January 1, 1946

Added to The UNT Digital Library

  • Nov. 17, 2011, 5:13 p.m.

Description Last Updated

  • Feb. 3, 2017, 6:59 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 318

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Miller, Cearcy D. Relation between spark-ignition engine knock, detonation waves, and autoignition as shown by high-speed photography, report, January 1, 1946; (digital.library.unt.edu/ark:/67531/metadc60148/: accessed September 23, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.