Mentioned in ?
References in periodicals archive ?
4 Atkinson cycle petrol engine replaces the previous regular Otto cycle 2.
The V8 engine adopts Atkinson cycle to enhance fuel efficiency at cruising speeds and Otto cycle for higher performance levels when accelerating.
The isothermal compressor could be used as the compression stage in an Otto cycle engine, enabling the use of a higher compression ratio and improving efficiency.
The clever bit is that by using variable valve timing the engine can swap from the conventional Otto cycle to the Atkinson cycle (in which the inlet valves are held open longer and allow air to reverse flow through the inlet manifold) to save fuel at cruising speeds.
For decades, efforts to meet ever-increasing standards like this have depended on a thorough understanding of Otto cycle dynamics in internal combustion engines and development of ways to change emissions through exhaust gas recirculation (EGR).
The Dual Variable Valve Timing with intelligence (VVT-iW) system allows the engine to start in the Otto cycle and then run in the more fuel efficient Atkinson cycle (there is late intake valve closing during the Atkinson cycle which reduces pumping losses and boosts fuel economy; the "W" in the engine descriptor nomenclature stands for "wide," as in a wider intake cam timing control).
When fully developed with its turbocharged and Air-Hybrid components, the engine is expected to achieve significant gains in fuel efficiency--the most since the inception of the Otto cycle over 130 years ago, according to the company.
To the Editor: Paul Sharke's article "Otto or Not" (June 2000) makes a good argument for increasing compression ratio in the Otto cycle engine at reduced load.
This has resulted in an engine that is significantly more energy-efficient than traditional gas-powered engines in which the biogas combusts in an Otto cycle," says Inge Horkeby, Director Environmental Affairs AB Volvo.