Volumetric Efficiency and Air-Fuel Ratio Analysis For Flex Fuel Engines

Engler-Pinto, Claudio M.; Nadai, Leandro de

doi:10.4271/2008-36-0223

Cited by 10 publications

(4 citation statements)

References 5 publications

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“…The IMEP increased with the increased DI% may be attributed to two main reasons. Firstly, the charge cooling effect due to ethanol's great latent heat of vaporisation associated with DI injection strategy might increase the fresh charge density hence allowing more air to be charged during the intake stroke [35]. Secondly, the oxygen content of ethanol fuel and the high combustion speed might help improve the combustion.…”

Section: Resultsmentioning

confidence: 99%

Effect of Spark Timing on Performance and Emissions of a Small Spark Ignition Engine with Dual Ethanol Fuel Injection

Al-Muhsen

Hong

2017

SAE Technical Paper Series

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Ethanol as a renewable fuel has been used widely in vehicles. Dual fuel injection is one of the new techniques in development for increasing the engine's thermal efficiency and reducing the pollutant emissions. This study reports experimental investigation to the dual ethanol fuel injection with a focus on the effect of spark timing on the engine performance at different volumetric ratios of ethanol directly injected to ethanol port injected. Experiments were conducted on a single cylinder 250cc spark ignition engine at two engine loads and 3500 RPM. The spark timing was varied from 15 to 42 CAD bTDC at the light load and from 15 to 32 CAD bTDC at the medium load, while the volumetric ratio of direct injection (DI%) was varied from 0% to 100%. Experimental results showed that DI100%, the best indicated mean effective pressure (IMEP) and thermal efficiency occurred at around 30 CAD bTDC at the light load and 23 CAD bTDC at the medium load, which were the minimum spark advance for the best torque (MBT). At MBT spark timing, the IMEP at DI56% and light engine load was 8.28% greater than that at 15 CAD bTDC which was the original spark timing set by the manufacturer, and the combustion duration (CA10-90%) was 41.8% shorter. These results were attributed to the improved combustion phase associated with the increased combustion pressure and temperature when the spark timing was advanced. However, the indicated specific hydrocarbon and carbon monoxide emissions increased with advanced spark timing and increased DI ratio. These could be caused by local rich mixture formed by fuel impinged to the chamber walls and the ethanol's cooling effect associated with the direct injection. On the other hand, because of the charge cooling effect of DI, the indicated specific nitric oxide emission decreased with increased DI ratio. At MBT timing and light load, the indicated specific nitric oxide emission decreased by 37.53% at DI56% and 67.39% at DI100% compared to port injection only.

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Section: Resultsmentioning

confidence: 99%

Effect of Spark Timing on Performance and Emissions of a Small Spark Ignition Engine with Dual Ethanol Fuel Injection

Al-Muhsen

Hong

2017

SAE Technical Paper Series

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“…Entretanto, no uso de E100 (situação mais crítica), constatou-se que para determinado motor de estudo a diferença na eficiência volumétrica com relação à gasolina é sempre menor que 5% independente das condições de operação [11]. Em outro estudo, para E85, constatou-se que esta diferença é sempre menor que 4% para outro motor de estudo [10].…”

Section: Modelagem Do Fluxo De Massa Através De Um Cilindrounclassified

Modelagem Dos Sistemas De Admissão De Ar Para Motores Com Tecnologia Flex

Silva¹,

Langaná²

2017

Blucher Engineering Proceedings

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RESUMONeste artigo é apresentado um modelo do sistema de admissão de ar para motores com tecnologia FLEX. O objetivo é fornecer uma formulação matemática para, por meio de análise teórica e métodos de identificação experimental, poder predizer a massa gasosa admitida pelo cilindro através do sinal dos atuadores e sensores deste sistema. Para o caso dos motores convencionais, esses atuadores são a válvula borboleta e a válvula de recirculação, e o sensoriamento é operado apenas pelo MAP. Para formular esta relação, estudos sobre o comportamento dos fenômenos nas válvulas, nos coletores, nos dutos e no próprio cilindro são desenvolvidos. Análises específicas sobre como a composição influencia estes fenômenos são realizadas, de forma a poder empregar estes modelos em motores com tecnologia FLEX. Métodos de identificação experimental para o caso específico da modelagem de sistema de admissão são apresentados, visando aproximar os resultados experimentais das formulações do modelo. INTRODUÇÃOO sistema de admissão de ar pode ser dividido nos seguintes subsistemas: válvulas, coletores e cilindro. Neste artigo, será feita a modelagem de cada um destes subsistemas de forma a predizer a massa de ar admitida, grandeza necessária para fazer o design e execução de controles, como o do torque e da relação ar/combustível.

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“…Slow evaporation rate at low ambient temperature, lower vapour pressure, and heating value are also reported to ethanol fuel as an issue of cold starting [8,9]. As a result, flex-fuel systems were widely used as auxiliary system to aid SI engine cold starting by using gasoline port injection (GPI) [10]. Flex-fuel systems were widely used in the US and South America, such as Brazil, to reduce CO2 emission by transferring the SI engines from gasoline-fueled to be 100% ethanol engines [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Performance of Combustion and Emissions Characteristics of Ethanol Dual Injection Spark Ignition Engine

Al-Muhsen

Hong

Ismail

2021

IJAME

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Ethanol dual injection (DualEI) is a new technology to maximise the benefits of ethanol fuel to the spark-ignition engine. In this study, the combustion and emissions characteristics in a DualEI spark-ignition engine with a variation of the direct injection (DI) ratio and engine speed were experimentally investigated. The volume ratio of DI was varied from 0% (DI0%) to 100% (DI100%), and two engine speeds of 3500 and 4000 RPM were tested. The spark timing for maximum brake torque (MBT) was first determined, and then the results of the effect of DI ratio on the engine performance at the MBT conditions were discussed and analysed. The results showed that the MBT timing for the DI and spark timings were 330 and 30 CAD bTDC, respectively. At the MBT timing, the indicated mean effective pressure slightly increased from 0.47 to 0.50 MPa when the DI ratio increased from DI0% to DI100%. However, the maximum combustion pressure significantly decreased by 8.32%, and volumetric efficiency increased by 4.04%. This was attributed to the reduced combustion temperature due to the cooling effect of ethanol fuel enhanced by the DI strategy. The indicated specific carbon monoxide and hydrocarbons significantly increased due to poor mixture quality caused by fuel impingement associated with the overcooling effect. However, the indicated specific nitric oxides significantly decreased due to the temperature reduction inside the combustion chamber. Results showed the potential of DualEI to increase the compression ratio and consequently increase the engine thermal efficiency without the risk of engine knock.

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Volumetric Efficiency and Air-Fuel Ratio Analysis For Flex Fuel Engines

Cited by 10 publications

References 5 publications

Effect of Spark Timing on Performance and Emissions of a Small Spark Ignition Engine with Dual Ethanol Fuel Injection

Effect of Spark Timing on Performance and Emissions of a Small Spark Ignition Engine with Dual Ethanol Fuel Injection

Modelagem Dos Sistemas De Admissão De Ar Para Motores Com Tecnologia Flex

Performance of Combustion and Emissions Characteristics of Ethanol Dual Injection Spark Ignition Engine

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