Combustion Approach for Downsizing: the IFP Concept

Pagot, Alexandre; Duparchy, A.; Gautrot, Xavier; Leduc, Pierre; Monnier, Gaëtan

doi:10.2516/ogst:2006009x

Cited by 12 publications

(11 citation statements)

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“…3(a). The purpose of a pulse divided exhaust manifold is to isolate the exhaust gas flow arriving from separate groups of cylinders until it reaches the turbine, thereby maintaining pulse energy [4]. In this way, the gas exchange process in one cylinder is not disturbed by pressure pulses emanating from other cylinders.…”

Section: Pulse Divided Exhaust Manifoldmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…High levels of residual gas is a prevalent factor for engine knock [4], which in spark-ignition engines is a phenomenon whereby the air-fuel mixture spontaneously combusts prior to spark plug ignition. This causes higher thermal and mechanical stresses that promote greater risk of mechanical failure of the piston or cylinder head.…”

Section: Introductionmentioning

confidence: 99%

“…Preserving the maximum amount of exhaust pulse energy will result in increased turbine power and energy transfer to the compressor, hence faster turbocharger acceleration and thus improved engine transient response. However, the presence of higher pressure at the cylinder exhaust ports drives greater pumping work, while the consequent poor scavenging leads to an increase in the amount of residual gas in the cylinder, thereby increasing the tendency for engine knock [4].One of the ways to mitigate the propensity for knock is to increase effective turbine size by raising the ratio of the throat area to radius (A/R) of the turbine, which reduces back pressure and thus the residual gas concentration in the cylinders. However, a larger turbine causes slower transient response, especially at low engine speeds.…”

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confidence: 99%

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Turbocharger Matching Method for Reducing Residual Concentration in a Turbocharged Gasoline Engine

Ismail¹,

Costall²,

Martinez-Botas³

et al. 2015

SAE Technical Paper Series

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In a turbocharged engine, preserving the maximum amount of exhaust pulse energy for turbine operation will result in improved low end torque and engine transient response. However, the exhaust flow entering the turbine is highly unsteady, and the presence of the turbine as a restriction in the exhaust flow results in a higher pressure at the cylinder exhaust ports and consequently poor scavenging. This leads to an increase in the amount of residual gas in the combustion chamber, compared to the naturally-aspirated equivalent, thereby increasing the tendency for engine knock. If the level of residual gas can be reduced and controlled, it should enable the engine to operate at a higher compression ratio, improving its thermal efficiency. This paper presents a method of turbocharger matching for reducing residual gas content in a turbocharged engine. The turbine is first scaled to a larger size as a preliminary step towards reducing back pressure and thus the residual gas concentration in-cylinder. However a larger turbine causes a torque deficit at low engine speeds. So in a following step, pulse separation is used. In optimal pulse separation, the gas exchange process in one cylinder is completely unimpeded by pressure pulses emanating from other cylinders, thereby preserving the exhaust pulse energy entering the turbine. A pulse-divided exhaust manifold enables this by isolating the manifold runners emanating from certain cylinder groups, even as far as the junction with the turbine housing.This combination of appropriate turbine sizing and pulse-divided exhaust manifold design is applied to a Proton 1.6-litre CamPro CFE turbocharged gasoline engine model. The use of a pulse-divided exhaust manifold allows the turbine to be increased in size by 2.5 times (on a mass flow rate basis) while maintaining the same torque and power performance. As a consequence, lower back pressure and improved scavenging reduces the residual concentration by up to 43%, while the brake specific fuel consumption improves by approx. 1%, before any modification to the compression ratio is made. IntroductionMany efforts have been made globally to reduce greenhouse gasses, particularly the CO 2 emissions produced by motor vehicles. Based on a study of global atmospheric trace gases by the Carbon Dioxide Information Analysis Center (CDIAC), CO 2 has increased from 280ppm pre-1750 to 386ppm in 2009, an increase of 106ppm. Modern road vehicles are required to meet stringent emission and fuel economy requirements, and several emission standards for passenger cars are already established or are currently being proposed to tackle climate change, and some are in the process of revision. For example, the European Commission aims to reduce CO 2 emissions from light-duty vehicles to a level of 95g/km by 2020 [1]. As a consequence, researchers and manufacturers have been investigating advanced technologies to meet these demands. One method that can be viewed as a viable short-to-medium term solution [2] is to use a smaller capacity engine that...

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Section: Pulse Divided Exhaust Manifoldmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Turbocharger Matching Method for Reducing Residual Concentration in a Turbocharged Gasoline Engine

Ismail¹,

Costall²,

Martinez-Botas³

et al. 2015

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…This cannot be done without increasing the density of the air introduced into the engine. Turbocharging is the boosting technology generally used in today's market and is the subject of extensive research, which seeks to overcome its drawbacks, such as low-end torque, turbo-lag [1,2] and compressor surge [3,4].…”

Section: Introductionmentioning

confidence: 99%

Influence of the lubricating oil pressure and temperature on the performance at low speeds of a centrifugal compressor for an automotive engine

Podevin

Clenci

Descombes

2011

Applied Thermal Engineering

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International audienceCurrently, turbocharged common rail high pressure direct injection Diesel engines are regarded as state-of-the-art. The use of the turbocharging technique in gasoline engines is also increasing, in order to achieve further fuel consumption reductions via downsizing. As the specific power outputs of both Diesel and gasoline engines rise, the low-end torque behavior of such engines and turbo-lag are becoming increasingly critical. This is primarily a result of the specific characteristics of turbochargers and internal combustion engines themselves

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Virtual Turbocharger as a Tool for Reality Simulation

Novotný

Vacula

Kudláček

2021

Mechanisms and Machine Science

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The mobility of people and the transport of goods requires powertrains. These powertrains often include internal combustion engines with turbocharging technology. The development of turbochargers requires an increase in their efficiency, for example in the form of reduced mechanical losses. In parallel, however, related processes such as vibration, gas blow-by through the sealing system or lubricant consumption still need to be addressed. The virtual turbocharger is a multiphysical tool for the coupled solution of these processes. This physically wide model is described by a system of differential and algebraic equations, assembled in a multibody system, discretized and solved numerically. The solution results are suitable for calibration by experiments on real turbocharger. A reasonably good agreement with experiments is achieved using the example of a truck engine turbocharger. In terms of the physical description of the processes, the development of computational modelling will continue to proceed simultaneously in two different directions. On the one hand by trying to increase the depth of the physical description, on the other hand by including more physical problems within a single virtual prototype.

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Combustion Approach for Downsizing: the IFP Concept

Cited by 12 publications

References 4 publications

Turbocharger Matching Method for Reducing Residual Concentration in a Turbocharged Gasoline Engine

Turbocharger Matching Method for Reducing Residual Concentration in a Turbocharged Gasoline Engine

Influence of the lubricating oil pressure and temperature on the performance at low speeds of a centrifugal compressor for an automotive engine

Virtual Turbocharger as a Tool for Reality Simulation

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