Image-producing knocking investigations in a two-stroke SI engine

Abstract

In an effort to reduce the carbon footprint of handheld devices, alcohol blended fuels represent an economically viable option with different alcohols available from renewable sources. On the technical side, it is to be investigated how alcohol-blends affect engine operation, by means of a thermodynamic study.

Two-stroke machines exhibit a combustion anomaly called four-stroke-knock. Since the propensity to knocking combustion is affected by alcoholic components in fuel, this effect has been investigated and will be discussed in this paper. A special focus lies on measuring flame propagation and fuel mixture preparation using high-speed visualization techniques under knocking conditions.