scholarly journals Dynamic control of a SI engine with variable intake valve timing

2003 ◽  
Vol 13 (5) ◽  
pp. 399-420 ◽  
Author(s):  
Jun-Mo Kang ◽  
J.W. Grizzle
Keyword(s):  
Dynamic Control ◽  
Intake Valve ◽  
Valve Timing ◽  
Si Engine

Analysis of Variable Intake Runner Lengths and Intake Valve Open Timings on Engine Performances

2014 ◽  
Vol 663 ◽  
pp. 336-341 ◽  
Author(s):  
Mohd Farid Muhamad Said ◽  
Zulkarnain Abdul Latiff ◽  
Aminuddin Saat ◽  
Mazlan Said ◽  
Shaiful Fadzil Zainal Abidin
Keyword(s):  
Engine Performance ◽  
Intake Manifold ◽  
Intake Valve ◽  
Si Engine ◽  
Engine Simulation ◽  
Engine Model ◽  
Optimum Parameters ◽  
Comparison Results ◽  
Variable Valve ◽  
Engine Development

In this paper, engine simulation tool is used to investigate the effect of variable intake manifold and variable valve timing technologies on the engine performance at full load engine conditions. Here, an engine model of 1.6 litre four cylinders, four stroke spark ignition (SI) engine is constructed using GT-Power software to represent the real engine conditions. This constructed model is then correlated to the experimental data to make sure the accuracy of this model. The comparison results of volumetric efficiency (VE), intake manifold air pressure (MAP), exhaust manifold back pressure (BckPress) and brake specific fuel consumption (BSFC) show very well agreement with the differences of less than 4%. Then this correlated model is used to predict the engine performance at various intake runner lengths (IRL) and various intake valve open (IVO) timings. Design of experiment and optimisation tool are applied to obtain optimum parameters. Here, several configurations of IRL and IVO timing are proposed to give several options during the engine development work. A significant improvement is found at configuration of variable IVO timing and variable IRL compared to fixed IVO timing and fixed IRL.

Variable Valve Timing Implemented with a Secondary Valve on a Four Cylinder SI Engine

1997 ◽  
Author(s):  
Olivier Vogel ◽  
Kimon Roussopoulos ◽  
Lino Guzzella ◽  
James Czekaj
Keyword(s):  
Variable Valve Timing ◽  
Valve Timing ◽  
Si Engine ◽  
Variable Valve

Engine In-Cylinder Flow Control via Variable Intake Valve Timing

2013 ◽  
Author(s):  
Isabella Bücker ◽  
Daniel-Christian Karhoff ◽  
Michael Klaas ◽  
Wolfgang Schröder
Keyword(s):  
Flow Control ◽  
Intake Valve ◽  
Valve Timing ◽  
Cylinder Flow

Variable Intake Valve Train to Optimize the Performance of a Large Bore Gas Engine

2016 ◽  
Author(s):  
Jan Zelenka ◽  
Claudio Hoff ◽  
Andreas Wimmer ◽  
Roland Berger ◽  
Josef Thalhauser
Keyword(s):  
Valve Train ◽  
Experimental Investigations ◽  
Intake Valve ◽  
Valve Timing ◽  
Current Standard ◽  
Gas Engine ◽  
Engine Efficiency ◽  
Variable Valve Train ◽  
Operating Strategies ◽  
Variable Valve

The present paper describes the investigations made using the electro-hydraulic intake valve timing system VCM® on a large bore gas engine. The first section explains what challenges have to be faced when developing concepts for present and future applications of large bore gas engines. Following an introduction to the VCM® system, an outline is presented of expected opportunities for using variable intake valve timing in combination with modern turbocharging concepts. The second section describes 0D/1D engine cycle simulations that were carried out to assess the influence of variable valve timing on the intake side compared to a fixed intake valve profile, which is the current standard for large bore gas engines. As a result, first predictions can be made about the gain in engine efficiency achieved with different operating strategies. In order to assess the performance potentials of the variable valve train, extensive experimental investigations were carried out on a single cylinder research engine based on GE’s Type 6 gas engine. The investigations consisted of varying engine parameters including varying the geometric compression ratio as well as the engine boundary conditions. It will be shown how intake valve timing can be used to optimize engine efficiency by improving gas exchange. Furthermore, variable intake valve timing affects the overall system behavior, e.g. distances to the engine’s operating limits. Special attention was paid to analyzing combustion itself, which is necessary due to the strong influence that intake valve timing has on the thermodynamic states of the cylinder charge.

Modeling the Effects of Variable Intake Valve Timing on Diesel HCCI Combustion at Varying Load, Speed, and Boost Pressures

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
C. L. Genzale ◽  
S.-C. Kong ◽  
R. D. Reitz
Keyword(s):  
Operating Conditions ◽  
Effective Control ◽  
Intake Valve ◽  
Valve Timing ◽  
Detailed Chemical Kinetics ◽  
Hcci Combustion ◽  
Wide Range ◽  
Particulate Matter Emissions ◽  
Charge Mixture ◽  
Ignition And Combustion

Homogeneous charge compression ignition (HCCI) operated engines have the potential to provide the efficiency of a typical diesel engine, with very low NOx and particulate matter emissions. However, one of the main challenges with this type of operation in diesel engines is that it can be difficult to control the combustion phasing, especially at high loads. In diesel HCCI engines, the premixed fuel-air charge tends to ignite well before top dead center, especially as load is increased, and a method of delaying the ignition is necessary. The development of variable valve timing (VVT) technology may offer an important advantage in the ability to control diesel HCCI combustion. VVT technology can allow for late intake valve closure (IVC) times, effectively changing the compression ratio of the engine. This can decrease compression temperatures and delay ignition, thus allowing the possibility to employ HCCI operation at higher loads. Furthermore, fully flexible valve trains may offer the potential for dynamic combustion phasing control over a wide range of operating conditions. A multidimensional computational fluid dynamics model is used to evaluate combustion event phasing as both IVC times and operating conditions are varied. The use of detailed chemical kinetics, based on a reduced n-heptane mechanism, provides ignition and combustion predictions and includes low-temperature chemistry. The use of IVC delay is demonstrated to offer effective control of diesel HCCI combustion phasing over varying loads, engine speeds, and boost pressures. Additionally, as fueling levels are increased, charge mixture properties are observed to have a significant effect on combustion phasing. While increased fueling rates are generally seen to advance combustion phasing, the reduction of specific heat ratio in higher equivalence ratio mixtures can also cause noticeably slower temperature rise rates, affecting ignition timing and combustion phasing. Variable intake valve timing may offer a promising and flexible control mechanism for the phasing of diesel HCCI combustion. Over a large range of boost pressures, loads, and engine speeds, the use of delayed IVC is shown to sufficiently delay combustion in order to obtain optimal combustion phasing and increased work output, thus pointing towards the possibility of expanding the current HCCI operating range into higher load points.

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