Study on Impulse Charger for Enhancement of Volumetric Efficiency of SI Engine

Downsizing the engine would be an effective means of improving fuel economy and reducing CO₂ emissions. In this case, low-speed torque generation can be enhanced through the use of impulse charging technology, a subject attracting the attention of many researchers. This paper reports the basic characteristics of impulse charging identified through research using a single-cylinder test engine, aiming for application of the technology to spark ignition (SI) engines. To ensure the maximum level of volumetric efficiency under impulse charging conditions, two requirements are controlling the timing of switching from a negative to a positive pressure wave while turning its direction at the intake chamber, and maximizing the positive pressure wave.