Air Flow Optimization and Calibration in High-Compression-Ratio Naturally Aspirated SI Engines with Cooled-EGR
As part of the U.S. Environmental Protection Agency (U.S. EPA) “Midterm Evaluation of Light-duty Vehicle Standards for Model Years 2022-2025 [1]”, the U.S. EPA is evaluating engines and assessing the effectiveness of future engine technologies for reducing CO2 emissions. Such assessments often require significant development time and resources in order to optimize intake and exhaust cam variable valve timing (VVT), exhaust gas recirculation (EGR) flow rates, and compression ratio (CR) changes. Mazda
Cylinder deactivation for CO2 reduction of 3-cylinder gasoline engines
Ever growing need for fuel efficiency improvement combined with new WLTC driving cycle and large penetration of 3-cylinder gasoline engines in Europe, has incentive Eaton to developing unique technical solution that allows cylinder deactivation on 3-cylinder gasoline engines, targeting CO2 reduction. The focus is on development mechanical Variable Valve Actuation system that enables Dynamic Cylinder Deactivation; where each cylinder operates in mode where one cycle is active (combustion) and next cycle is deactivated. In this way, the 3-cylinder engine would virtually run in 1 ½ cylinder mode.
MITSUBISHI ORION-MD--A NEW VARIABLE DISPLACEMENT ENGINE
A 1.4-liter, 4-cylinder variable-displacement engine was developed as an optional powerplant for a subcompact passenger car. In order to maximize its fuel saving effects, incorporated in the engine are unique valve deactivation devices which are electrically controlled and activated by means of engine oil. Several measures were taken to assure smooth cylinder switching and to cope with the problems caused by reducing the number of operating cylinders from 4 to 2. Thus without deteriorating the driveability, nearly 20% reduction of fuel consumption in the Japanese 10-Mode Cycle was achieved by this engine.