The frequency of the pressure oscillations caused by spark knock depends on the temperature-dependent speed of sound in the combustion gases. Engine dynamometer tests showed a 6.5% (390 Hz) reduction in the knock fundamental frequency as the air/fuel ratio was swept from 13:1 to 20:1. Engine cycle simulation model predictions of maximum burned gas temperatures correlate well with the data. A robust knock detection system must be insensitive to the range of burned gas temperature (frequency of pressure oscillations) that will be encountered with a particular engine control system operating under the expected range of fuels and environmental conditions.
Detection of Spark Knock Oscillations: Dependence on Combustion Temperature
Sae Technical Papers
International Congress & Exposition ; 1997
1997-02-24
Aufsatz (Konferenz)
Englisch
Detection of spark knock oscillations: dependence on combustion temperature
Kraftfahrwesen | 1997
|knock-knock: Spark Knock, Wild Ping, or Rumble?
SAE Technical Papers | 1959
|Knock knock -- Spark knock, wild ping or rumble?
Engineering Index Backfile | 1958
|Adaptive Spark Control with Knock Detection
SAE Technical Papers | 1984
|Adaptive Spark Control with Knock Detection
Kraftfahrwesen | 1984
|