The Third Generation of Valvetrains - New Fully Variable Valvetrains for Throttle-Free Load Control

Flierl, Rudolf; Klüting, Manfred

doi:10.4271/2000-01-1227

Cited by 134 publications

(55 citation statements)

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“…By the end of 1990's, mechanical fully variable valvetrains were developed, e.g. BMW Valvetronics system [1] and several other manufacturers have developed their own continuous variable mechanical valve lift devices over the last few years [2][3][4][5]. More recently, Fiat introduced the most flexible production VVA system, the electro-hydraulic actuated multi-air VVA, in their production engines.…”

Section: Introductionmentioning

confidence: 99%

Investigation of combustion, performance and emission characteristics of 2-stroke and 4-stroke spark ignition and CAI/HCCI operations in a DI gasoline

Zhang

Zhao

2014

Applied Energy

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Highlights:1. It was the first time 7 operating modes were achieved on the same engine.2. 7 operating modes covers conventional spark ignition and advanced controlled autoignition in two-stroke and 4-stroke cycles.3. The thermodynamic cycle, combustion process and efficiencies are analysed and presented. ABSTRACTIn order to develop more efficient and cleaner gasoline engines, a number of new engine operating strategies have been proposed and researched on different engines, including the spark ignition (SI) and controlled autoignition (CAI) or HCCI in both 2-stroke and 4-stroke cycles in a poppet valve engine. In this work, a single cylinder direct injection gasoline engine equipped with an electro-hydraulic valve-train system has been commissioned and used to achieve seven different operating modes, including: 4-stroke throttle-controlled SI, 4-stroke intake valve throttled SI, 4-stroke positive valve overlap SI, 4-stroke negative valve overlap CAI, 4-stroke exhaust rebreathing CAI, 2-stroke CAI and 2-stroke SI. Their performance and emission characteristics were analysed and compared at a typical engine calibration operating condition of 1500rpm and 3.6bar IMEP in 4-stroke or 1.8bar IMEP in 2-stroke. Results show that 4-stroke positive valve overlap SI, 4-stroke NVO CAI and exhaust rebreathing CAI modes have better fuel economy and lower NOx emissions than the conventional throttled 4-stroke SI operation. The 2-stroke CAI operation was found to produce higher combustion efficiency and lower ISFC but lower brake efficiency than the 4-s-stroke operations at the same power output due to the supercharger's efficiency. But, at the same IMEP as the 4-stroke operation, the 2-stroke CAI operation results in 29% reduction in BSFC, indicating its potential synergy with highly downsized direct injection gasoline engines for much better fuel economy and performance.

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Section: Introductionmentioning

confidence: 99%

Investigation of combustion, performance and emission characteristics of 2-stroke and 4-stroke spark ignition and CAI/HCCI operations in a DI gasoline

Zhang

Zhao

2014

Applied Energy

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“…A combined VCP and CPS VVA is the most advanced design in production. BMW's mechanical Valvetronic™ VVA system uses a continuously variable CPS for the intake valve in addition to VCP VVAs for the intake and exhaust camshafts [19]. This design offers independent phase control for the intake and exhaust camshafts and combined lift and duration control for the intake camshaft.…”

Section: Previous Vva Designsmentioning

confidence: 99%

“…These include FEV [21], [22], [24], BMW [19], [25], GM [23], Renault [26], [27], Siemens [28], [29], and Aura [30]. Note that in the idealized action described above, the actuators do no work because they apply force only when the valve has zero velocity.…”

Section: Normal-force Actuator Based Emvd Designmentioning

confidence: 99%

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An Electromechanical Valve Drive Incorporating a Nonlinear Mechanical Transformer

Chang¹,

Parlikar²,

Kassakian³

et al. 2003

SAE Technical Paper Series

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“…Flexible systems have thus become increasingly attractive as means of achieving optimal engine-in-vehicle operation. Advanced Variable Valve Actuation (VVA) technologies are particularly promising in saving fuel, reducing emissions and increasing Spark-Ignition (SI) engine output [1][2][3][4][5]. Among various VVA options, cam-phasing is gaining broad acceptance, due to its ease of implementation and tangible advantages over conventional fixed-cam engines [6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

A Simulation-Based Approach for Developing Optimal Calibrations for Engines with Variable Valve Actuation

Filipi

Prucka

et al. 2007

Oil & Gas Science and Technology - Rev. IFP

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Résumé -Une approche basée sur la simulation pour le développement de réglages optimaux des moteurs avec système d'actionnement variable de soupape -La technologie d'actionnement variable de soupape (Variable Valve Actuation, VVA) présente un fort potentiel pour augmenter les performances et réduire consommation et pollution. Les avantages du VVA proviennent d'une meilleure aération et de la possibilité de contrôler les résidus internes. Par contre, l'addition de variables de contrôle supplémentaires dans un moteur VVA augmente la complexité du système, ce qui nécessite la mise au point d'une stratégie de contrôle optimale afin d'en tirer tous les bénéfices. L'approche traditionnelle reposant sur l'expérimentation s'avère trop onéreuse dans ce cas du fait de l'augmentation exponentielle du nombre de tests. Ce projet propose comme alternative de définir le réglage des soupapes comme un problème d'optimisation. Il identifie les simulations nécessaires au développement d'une méthode générique capable d'intégrer un nombre croissant de degrés de liberté afin de développer un outil de grande fidélité pour la prédiction des effets de différents dispositifs. Puisque la résolution d'un problème d'optimisation requiert l'évaluation de centaines de fonctions, l'utilisation directe d'une simulation hautefidélité demande des temps de calculs beaucoup trop longs. En remplacement, un réseau artificiel de neurones est entraîné avec des résultats de simulation haute-fidélité et utilisé pour représenter la réponse du moteur à différentes combinaisons de variables de contrôle, et ce avec des temps de calcul beaucoup plus courts. Cet article décrit une méthode basée sur la simulation, apporte des détails sur les techniques de modélisation haute-fidélité et démontre une application à un prototype de moteur à essence à quatre cylindres et double arbre à cames indépendant. Abstract

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The Third Generation of Valvetrains - New Fully Variable Valvetrains for Throttle-Free Load Control

Cited by 134 publications

References 0 publications

Investigation of combustion, performance and emission characteristics of 2-stroke and 4-stroke spark ignition and CAI/HCCI operations in a DI gasoline

Investigation of combustion, performance and emission characteristics of 2-stroke and 4-stroke spark ignition and CAI/HCCI operations in a DI gasoline

An Electromechanical Valve Drive Incorporating a Nonlinear Mechanical Transformer

A Simulation-Based Approach for Developing Optimal Calibrations for Engines with Variable Valve Actuation

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