New Turbocharging Systems for Two-Stroke Cycle Diesel Engines 700075

The paper describes the development of new methods of turbocharging 2-stroke cycle engines. Work on the normal simple system, which has a turbocharger alone, and the series turbocharging system which employs a Roots blower after the turbocharger, showed their limitations and potentialities. In developing a system incorporating the best features of each, the throughput of the engine driven blower was controlled to make the air delivery of the series turbocharging system more similar to that obtained with simple turbocharging, thus greatly improving the fuel consumption and torque curve of a vehicle sized engine.A second change was to use the two types of charging systems on the same engine, thereby halving the size and parasitic losses of the engine driven blower. This gave further improvement in fuel consumption and is suitable for engines large enough to use two turbochargers.