Browse Publications Technical Papers 2000-01-2840

The Influence of Residual Gases on Knock in Turbocharged SI-Engines 2000-01-2840

In this investigation the influence on knock from the residual gas in the cylinder is investigated. Gas was sampled from inside the cylinder prior to ignition, the Residual Gas Fraction, RGF, was determined and the Knock Intensity, KI, was measured. By altering the exhaust backpressure the RGF was changed. By measuring the knock intensity for different RGF the influence on knock from residual gas was investigated.
It is shown that with increased residual gas fraction the knock propensity of the engine is increased, and subsequently, decreased RGF gives lower knock intensity. This is showed by the fact that, with maintained knock intensity at 30 kPa, the ignition timing can be advanced as much as 5 Crank Angle Degrees, CAD, if the RGF is reduced with 15%.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 40% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.