scholarly journals Review of Advancement in Variable Valve Actuation of Internal Combustion Engines

2020 ◽  
Vol 10 (4) ◽  
pp. 1216 ◽  
Author(s):  
Zheng Lou ◽  
Guoming Zhu
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Efficiency ◽  
Combustion Engines ◽  
Mechatronic Systems ◽  
Variable Valve Actuation ◽  
Increasing Demand ◽  
Electro Magnetic ◽  
Variable Valve ◽  
Valve Actuation

The increasing concerns of air pollution and energy usage led to the electrification of the vehicle powertrain system in recent years. On the other hand, internal combustion engines were the dominant vehicle power source for more than a century, and they will continue to be used in most vehicles for decades to come; thus, it is necessary to employ advanced technologies to replace traditional mechanical systems with mechatronic systems to meet the ever-increasing demand of continuously improving engine efficiency with reduced emissions, where engine intake and the exhaust valve system represent key subsystems that affect the engine combustion efficiency and emissions. This paper reviews variable engine valve systems, including hydraulic and electrical variable valve timing systems, hydraulic multistep lift systems, continuously variable lift and timing valve systems, lost-motion systems, and electro-magnetic, electro-hydraulic, and electro-pneumatic variable valve actuation systems.

Analysis and Simulation of an Oil Lubrication Pump for Internal Combustion Engines

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Emma Frosina ◽  
Adolfo Senatore ◽  
Dario Buono ◽  
Luca Santato
Keyword(s):  
Simulation Model ◽  
Internal Combustion Engines ◽  
Experimental Tests ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Oil Lubrication ◽  
Variable Valve Actuation ◽  
Depth Analysis ◽  
Pump Shaft ◽  
Variable Valve

This paper presents a simulation model of an oil-lubrication gerotor pump for internal combustion engines. The model was constructed by using a monodimensional commercial code that accounted for all phenomena that occur during the revolution of the pump shaft. Several geometric considerations and theoretical observations are presented. An experiment was also performed to validate the simulation model. In these experimental tests, particular attention was paid to the behavior of the pressure oscillations during the pump shaft revolutions. The final aim of this activity is to obtain an instrument that allows the in-depth analysis of the functioning of the pump and lubrication circuit. Additionally, this instrument can be coupled with other models (e.g., variable valve actuation (VVA) and variable valve timing (VVT)) to account for different problems experienced by the hydraulic components of engines.

A Simple Combustion Efficiency Indicator for Automobile Engines

1973 ◽  
Vol 6 (10) ◽  
pp. 399-400 ◽  
Author(s):  
M. S. Bolton ◽  
D. S. Taylor
Keyword(s):  
Carbon Monoxide ◽  
Internal Combustion Engines ◽  
Fuel Mixture ◽  
Internal Combustion ◽  
Combustion Efficiency ◽  
Exhaust Emission ◽  
Combustion Engines ◽  
Widespread Application ◽  
Mixture Ratio ◽  
Automobile Engines

A cheap device which can indicate carbon monoxide levels in exhaust emission of internal combustion engines, and hence could be used for adjusting the engine's operating air: fuel mixture ratio, would have widespread application in garages, etc. The instrument described here is sensitive to both unburnt hydrocarbons and carbon monoxide but measures the carbon monoxide to an accuracy well within the tuning capability of most carburation systems.

A physics-based approach to the control of homogeneous charge compression ignition engines with variable valve actuation

2005 ◽  
Vol 6 (4) ◽  
pp. 361-375 ◽  
Author(s):  
G M Shaver ◽  
M J Roelle ◽  
P A Caton ◽  
N B Kaahaaina ◽  
N Ravi ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Homogeneous Charge Compression Ignition ◽  
Control Strategies ◽  
Combustion Process ◽  
System Control ◽  
Compression Ignition ◽  
Variable Valve Actuation ◽  
Variable Valve ◽  
Homogeneous Charge ◽  
Valve Actuation

Homogeneous charge compression ignition (HCCI) is a promising low-temperature combustion strategy for reducing NOx emissions and increasing efficiency in internal combustion engines. However, HCCI has no direct combustion initiator and, when achieved by reinducting or trapping residual exhaust gas with a variable valve actuation (VVA) system, becomes a dynamic process as the temperature of the residual gas couples one cycle to the next. These characteristics of residual-affected HCCI present a challenge for control engineers and a barrier to implementing HCCI in a production engine. In order to address these challenges, this paper outlines physics-based control strategies for both the VVA system and the HCCI combustion process. The results show that VVA system control can provide arbitrary valve timings on a cycle-to-cycle basis, enabling tight control of HCCI. By abstracting these valve timings further into an inducted gas composition and an effective compression ratio, model-based controllers can be developed to control simultaneously load and combustion timing in an HCCI engine.

An Optimum Flexible Linkage Design of a Fully Variable Electromechanical Valve Actuation System for Internal Combustion Engines

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
D. T. Hossein Rokni ◽  
Rudolf J. Seethaler ◽  
Abbas S. Milani
Keyword(s):  
Internal Combustion Engines ◽  
Mechanical Design ◽  
Design Procedure ◽  
Experimental Tests ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Actuation System ◽  
Flexible Linkage ◽  
Valve Actuation

In this study, the mechanical design of a fully flexible valve actuation system (FFVA) for intake valves of naturally aspirated internal combustion engines is optimized. The original FFVA design used a connecting rod in order to transform the rotating motion of the actuator to translating motion of the valve. In the improved design introduced here, the connecting rod is replaced by a flexible linkage. This step is taken in order to eliminate wear and play in the mechanical connections. A detailed design procedure is presented to optimize the heavy fatigue load on this element. Simulations and experimental tests are carried out in order to validate the system performance. It is shown that valve trajectory and energy consumption of the actuation system obtained by simulations are consistent with those observed experimentally. The present redesigned FFVA system then provides more reliable valve motion than previously shown designs.

Linear Parameter-Varying Model of an Electro-Hydraulic Variable Valve Actuator for Internal Combustion Engines

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Huan Li ◽  
Ying Huang ◽  
Guoming Zhu ◽  
Zheng Lou
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Time Varying ◽  
Linear Parameter ◽  
Linear Parameter Varying ◽  
Varying Parameters ◽  
Operational Conditions ◽  
Time Varying Parameters ◽  
Variable Valve

This paper presents a novel linear parameter-varying (LPV) model of an electro-hydraulic variable valve actuator (EHVVA) for internal combustion engines that is capable of continuously varying valve timing with dual-lift. The dual-lift is realized mechanically through a hydraulic lift control sleeve; valve opening (VO) terminal and closing seating velocities are regulated using a top or bottom snubber; and opening and closing timings, as well as lift profile area, are controlled by the valve actuation timing and hydraulic supply pressure. First, nonlinear mathematical system model is developed based on the Newton's law, orifice flow equation, and fluid constitutive law, where the fluid dynamics of the actuation solenoid valve, actuation piston, passages, and orifices, that influence the engine valve profile, are considered in detail. Second, to have an LPV control-oriented model, the order of nonlinear model is reduced and subsequently transformed into an LPV model with minimal deviation by carefully considering the system nonlinearities, time delay, and time-varying parameters. Calibration and validation experiments for both nonlinear and LPV models were performed on the test bench under different operational conditions. The key time-varying parameters, the time constant of the actuation piston top pressure and the discharge coefficient, are highly nonlinear as functions of temperature-sensitive fluid viscosity and are determined using the test data through the least-squares optimization. With the identified and calibrated model parameters, simulation results of both nonlinear and LPV models are in good agreement with the experimental ones under different operational conditions.

Improved Mechanical Design for a Fully Variable Electromechanical Valve Actuation System for Internal Combustion Engines

2010 ◽  
Author(s):  
Hossein Rokni Damavandi Taher ◽  
Rudolf J. Seethaler ◽  
Abbas S. Milani
Keyword(s):  
Internal Combustion Engines ◽  
Mechanical Design ◽  
Experimental Tests ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Mechanical Vibrations ◽  
Actuation System ◽  
Ohmic Losses ◽  
Valve Motion ◽  
Valve Actuation

This study aims to improve the mechanical design of a fully flexible valve actuation system (FFVA) for intake valves of internal combustion engines. Optimization procedures for increasing the reliability and efficiency of the mechanical design of the FFVA system are presented. Simulations and experimental tests are carried out in order to validate the system performance. It is shown that position, velocity and acceleration of the valve obtained by simulations are consistent with those observed experimentally. Furthermore, it is observed that the mechanical vibrations are considerably reduced in the redesigned FFVA system. As a result, current levels and ohmic losses in the electric motor are also reduced. The present redesigned FFVA system then provides more reliable valve motion and better efficiency than the previously shown design [25].

A Cogging Torque Assisted Motor Driven Valve Actuation System for Internal Combustion Engines

2013 ◽  
Author(s):  
Bradley A. Reinholz ◽  
Rudolf J. Seethaler
Keyword(s):  
Internal Combustion Engines ◽  
High Efficiency ◽  
Acoustic Emissions ◽  
Internal Combustion ◽  
Performance Criteria ◽  
Combustion Engines ◽  
Cogging Torque ◽  
Actuation System ◽  
Stringent Performance ◽  
Valve Actuation

Electromechanical valve actuation (EVA) for internal combustion engines promises to significantly improve engine efficiency and lower emissions by reducing pumping losses and allowing for novel combustion strategies. However, current designs have not been able to meet the stringent performance criteria for reliability, efficiency, acoustic emissions, weight, and cost that are required by the automotive industry. This paper describes a novel cogging torque assisted motor driven (CTAMD) valve actuation system that promises to meet both the performance and robustness requirements. In contrary to existing EVA systems that recover the kinetic valve energy using a mechanical spring system, the CTAMD system recovers kinetic energy in a magnetic field. This allows for high efficiency while maintaining a simple and elegant electromechanical design. This paper describes the characteristics of CTAMD systems and outlines an electromechanical design for such a system. Then computer simulations of the proposed design are used to demonstrate the expected performance of the system. Finally, the simulated results are compared to other EVA systems to highlight the anticipated improvements.

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