Analysis of Dual-Charging Two Stroke Engine

A Dual-charging approach to reduce scavenged-through fuel losses have been studied and practical systems for two and three wheeler applications have been developed. In this paper the analysis of dual-charging approach have been made based on experimental results, and theoretical calculations of cylinder charging and scavenging.

The distinguishing feature of dual-charging is the incorporation of an additional intake which supplies either air alone or a portion of exhaust gases. The other intake supplies air-fuel mixture. This results in cylinder charging taking place in phases: initially air or a portion of recirculated exhaust, and later air-fuel mixture.

The analysis of experimental results have been made for the fuel and air trapping efficiencies alongwith the exhaust emissions. Based on theoretical calculations the concept of dual-charging has been analysed for the relative loss, and the loss-contribution of each phase of cylinder charging towards the total fuel loss into the exhaust. For both the cases the improvements in trapping efficiency and reductions in HC emissions have been predicted and compared with experimental results.