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Engine systems
Published in Tom Denton, Automobile Mechanical and Electrical Systems, 2018
Most modern petrol engines use a hemispherical or pent roof combustion chamber design. This shape provides the best compromise of surface to volume ratio; this reduces heat energy loss during the expansion stroke, which in turn improves the thermal efficiency of the engine. The combustion chamber design allows single- or dual-inlet and exhaust ports with cross-flow engine breathing. This design easily accommodates two to five valves per cylinder.
Operational feasibility of a spark ignition engine which is subjected to VTEC management strategy
Published in Australian Journal of Mechanical Engineering, 2020
Lucky Anetor, Edward E. Osakue
The four-valve pent roof combustion chamber configuration is commonly used in modern-day spark ignition engines, since it is capable of giving excellent brake specific fuel consumption or fuel economy and low emissions. The pent roof combustion chamber is always accompanied by barrel swirl which facilitates rapid burn rate. Fast-burn combustion chambers operate comfortably with high levels of exhaust gas recirculation regardless of whether the exhaust gas recirculation is being used for control of oxides of nitrogen or for regulating part-load fuel economy. The part-load fuel economy is reduced because exhaust gas recirculation leads to a decrease in the throttling loss. In order to admit a given quantity of air the throttle has to be wide open so as to reduce the pressure drop and loss of work across it.
Influence of modified pent roof combustion cavity on diesel engine performance and emission characteristics
Published in International Journal of Ambient Energy, 2019
L. Karikalan, M. Chandrasekaran, S. Ramasubramanian, P. Vivek
The pent roof chamber showed that during the intake process, strong tumbling vortices were generated by the jetting flow of the air around the inlet valves. Many researchers revealed that the pent roof combustion chamber design increases the air motion turbulence and improves the combustion process. In this work, a conventional piston with 87.5 × 110 mm of the KIRLOSKAR TV-1 single-cylinder diesel engine has been modified with a pent roof combustion chamber design with 6° and is shown in Figures 1 and 2.