Der neue 2,0-l-R4-TFSI-Motor von Audi

Budack, Ralf; Wurms, Rainer; Mendl, Günther; Heiduk, Thomas

doi:10.1007/s35146-016-0035-2

Cited by 4 publications

(2 citation statements)

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“…Considering mechanical issues such as friction [14] and mass balancing [15] it may nevertheless turn out to be more convenient to use Miller cycle process in short-term series solution [16] accepting some disadvantages in peak efficiency.…”

Section: Discussionmentioning

confidence: 99%

Extended expansion linkage engine: a concept to increase the efficiency

Dumböck

Schutting

Eichlseder

2018

Automot. Engine Technol.

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In a broad-based survey, the reciprocating piston engine with extended expansion stroke was found to have the highest efficiency potential for passenger car propulsion. To confirm the predicted efficiency, three different prototype engines were built and measured on testbed. Measurements were complemented with thermodynamic simulations. Investigations focused on naturally aspirated and supercharged SI engines. It could be shown that a naturally aspirated SI engine with an expansion ratio of 2 gains an efficiency improvement of 7 percentage points compared to a conventional crank train engine. It was also found that the extended expansion has no inherent effect to combustion, emission formation and wall heat transfer. Major effort was made to assess the Miller cycle as a thermodynamic alternative to the crank train with extended expansion. Measurements and simulations revealed that Miller suffers in a way from higher wall heat and gas exchange losses cutting a substantial share of the efficiency potential of an equivalent crank train solution. Keywords Extended expansion • Atkinson cycle • Miller cycle Abbreviations atm Atmospheric AFR Air to fuel ratio BDC Bottom dead centre BP Boost pressure CA Crank angle c Compression COMP Compressor Volume ratio Ex Expansion EE Extended expansion EGBP Exhaust gas back pressure c Compression ratio

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Section: Discussionmentioning

confidence: 99%

Extended expansion linkage engine: a concept to increase the efficiency

Dumböck

Schutting

Eichlseder

2018

Automot. Engine Technol.

View full text Add to dashboard Cite

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“…The range of employed techniques for engine downsizing can be considered from redesigning the engine components to general new engine designing or even the Engine Management System (EMS). Although, in the recent years, the researches focus is shifted to coping the operational challenges and performance improvement rather than redesigning [18,19]; it seems that there is still a great potential for ultra-downsizing yet [20]. A 50% downsized 3-cylinder engine optimal designing has been reported by Hancock et al [21], focusing on design structure and employed technologies, and 30% fuel economy plus CO2 reduction are reported as the results of their optimal design.…”

Section: Introductionmentioning

confidence: 99%