Variable Valve - Control Systems for Spark Ignition Engine

2001 ◽  
Author(s):  
Niculae Negurescu ◽  
Constantin Pana ◽  
Marcel Ginu Popa ◽  
Alexandru Racovitza
Keyword(s):  
Control Systems ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Variable Valve ◽  
Valve Control

Experimental research on pumping losses and combustion performance in an unthrottled spark ignition engine

2018 ◽  
Vol 232 (7) ◽  
pp. 888-897 ◽  
Author(s):  
Tingting Sun ◽  
Yingjie Chang ◽  
Zongfa Xie ◽  
Kaiyu Zhang ◽  
Fei Chen ◽  
...  
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Valve Lift ◽  
Combustion Characteristic ◽  
Spark Ignition Engines ◽  
Intake Valve ◽  
Valve System ◽  
Combustion Performance ◽  
Intake Swirl ◽  
Variable Valve

A novel fully hydraulic variable valve system is described in this paper, which achieves continuous variations in maximum valve lift, valve opening duration, and the timing of valve closing. The load of the unthrottled spark ignition engine with fully hydraulic variable valve system is controlled by using an early intake valve closing rather than the conventional throttle valve. The experiments were carried out on BJ486EQ spark ignition engine with fully hydraulic variable valve system. Pumping losses of the throttled and unthrottled spark ignition engines at low-to-medium loads are compared and the reason of it decreasing significantly in the unthrottled spark igntion engine is analyzed. The combustion characteristic parameters, such as cyclic variation, CA50, and heat release rate, were analyzed. The primary reasons for the lower combustion rate in the unthrottled spark ignition engines are discussed. In order to improve the evaporation of fuel and mix with air in an unthrottled spark ignition engine, the in-cylinder swirl is organized with a helical intake valve, which can generate a strong intake swirl at low intake valve lifts. The effects of the intake swirl on combustion performance are investigated. Compared with the throttled spark ignition engine, the brake specific fuel consumption of the improved unthrottled spark ignition engine is reduced by 4.1% to 11.2%.

Factors influencing the burn rate characteristics of a spark ignition engine with variable valve timing

2008 ◽  
Vol 222 (11) ◽  
pp. 2147-2158 ◽  
Author(s):  
F Bonatesta ◽  
P J Shayler
Keyword(s):  
Mass Fraction ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Spark Timing ◽  
Piston Speed ◽  
Flame Development ◽  
Variable Valve ◽  
Valve Overlap

The charge burn characteristics of a four-cylinder port-fuel-injected spark ignition engine fitted with a dual independent variable-valve-timing system have been investigated experimentally. The influence of valve timings on the flame development angle and the rapid burn angle is primarily associated with valve overlap values and internal gas recirculation. Conditions examined cover light to medium loads and engine speeds up to 3500r/min. As engine loads and speeds exceeded about 6bar net indicated mean effective pressure and 3000r/min respectively, combustion duration was virtually independent of the valve timing setting. At lower speeds and work output conditions, valve timing influenced burn angles through changes in dilution mass fraction, charge density, and charge temperature. Of these, changes in dilution mass fraction had the greatest influence. Increasing the dilution by increasing the valve overlap produced an increase in both burn angles. The effects of mean piston speed and spark timing have also been examined, and empirical expressions for the flame development and the rapid burn angles are presented.

Combustion Analysis on a Variable Valve Actuation Spark Ignition Engine Operating With E22 and E100

2017 ◽  
Author(s):  
Igor Trevas ◽  
Adm José baeta ◽  
Charles Pimenta ◽  
Heder Fernandes ◽  
Matheus Carvalho ◽  
...  
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Analysis ◽  
Variable Valve Actuation ◽  
Variable Valve ◽  
Valve Actuation
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