In-Cylinder Charge Motion Development for Gasoline Engine 2021-26-0062
In the recent years world-wide automotive manufacturers are continuously working in the research of the suiTable technical solutions to meet upcoming stringent carbon dioxide (CO2) emission targets, defined by regulatory authorities across the world. Many technologies have been already developed, or are currently under study, to meet the legislated targets.
To meet this objective, the generation of tumble at intake stroke and the conservation of turbulence intensity at the end of compression stroke inside the combustion chamber have a significant role in the contribution towards accelerating the burning rate, increasing the thermal efficiency and reducing the cyclic variability . Tumble generation is mainly attained by intake port design, and conservation is achieved during the end of compression stroke 690 ~ 720 crank angles (CA) which is strictly affected by the piston bowl geometry and pentroof combustion chamber shape. In this work, different geometries of intake port, combustion chamber (CC) and piston bowl have been designed and analyzed by means of transient computational fluid dynamics (CFD) software Converge to foresee the in-cylinder tumble motion development during suction stroke and tumble motion conservation during the compression stroke. Our main intention is to maximize the utilization of fluid energy of incoming charge at the form of combustion. This will help to minimize the delay in the start of combustion (SOC), promote high flame growth-rate and good combustion stability with reduced cycle to cycle variation. Final designs were manufactured and tested on actual engine in a test bench. Lower phasing loss and fast combustion have been attained with new intake port, combustion chamber and piston bowl geometries.