Stratified-Charge Engine Fuel Economy and Emission Characteristics

Brehob, Diana D.; Fleming, Jonathan E.; Haghgooie, M.; Stein, Robert A.

doi:10.4271/982704

Cited by 64 publications

(24 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…From this point onwards, the increase levels off and maximum values larger than 1·10 6 1/cm 3 are reached. The overall highest particle concentrations are produced by Fuel A with numbers larger than 2.4·10 6 1/cm 3 . In contrast to Fuels A and D, the two detergent containing blends (Fuel B and Fuel C) do not give a notable change in PN throughout the operating condition with higher speed and load.…”

Section: Engine Resultsmentioning

confidence: 99%

“…In that phase, particulate emission levels of all fuels remain relative constant with values between 1·10 4 and 3·10 4 particles per cm 3 . After the conditions were changed to the higher operating point of the engine, particulate numbers begin to deviate from their original levels.…”

Section: Engine Resultsmentioning

confidence: 99%

“…This opens up the possibility of new injection strategies and can improve efficiency and fuel consumption, especially under partial load [1,2,3]. An additional advantage is the so-called stratified charge operation, which allows adjustment of the injection and ignition timings of the engine, to further optimise engine operation [4].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Injector Fouling and Its Impact on Engine Emissions and Spray Characteristics in Gasoline Direct Injection Engines

Henkel

Hardalupas

Taylor

et al. 2017

SAE Int. J. Fuels Lubr.

View full text Add to dashboard Cite

Unlike in port fuel injection (PFI) systems, gasoline direct injection (GDI) engines deliver fuel directly into the combustion chamber. This opens up the possibility of new injection strategies and can improve efficiency and fuel consumption, especially under partial load [1,2,3]. An additional advantage is the so-called stratified charge operation, which allows adjustment of the injection and ignition timings of the engine, to further optimise engine operation [4]. In addition, the charge cooling effect observed during fuel injection allows for the use of higher compression ratios, with reduced risk of knocking. These benefits are gaining more attention with the continuing trend of downsizing and super-or turbocharging of engines, due to increasingly strict emissions regulations [5,6,7]. Additional benefits of GDI are the option to completely shut-off fuel supply while coasting [8] and improved cold start behaviour compared to PFI engines [9,10].One major challenge of the GDI concept, however, is the potential for increased formation of particulate emissions. Recent emissions legislations such as EURO 6 in Europe and LEV III (Low Emissions Vehicle Program) in the US pose very strict limitations on particle number and mass (PM) concentrations [11,12]. Methods to control particulate emissions from GDI engines are therefore important.Introduction of an injector into the combustion chamber of a GDI engine results in direct exposure of the injector tip to the harsh conditions occurring during combustion. Because the flame directly interacts with the nozzle, combustion products can be deposited on the surface and inside cavities. This is usually referred to as injector fouling or coking and can have an adverse effect on fuel consumption, engine performance and both hydrocarbons and particulate emissions. Formation of deposits on the injector tip can result in alteration of spray pattern leading to increased spray impingement and therefore increased particulate emissions [13,14,15,16].The phenomenon of injector fouling and how it is influenced by fuel and engine parameters was the focus of a number of studies. Aradi et al. [17] investigated different fuel blends under several conditions in a four cylinder engine. They used rich fuel-to-air ratios in order to promote fouling. By measuring the temperature of the injector tip with an internal sensor, they saw that with increasing temperature Injector Fouling and Its Impact on Engine Emissions and Spray Characteristics in Gasoline Direct Injection Engines ABSTRACTIn Gasoline Direct Injection engines, direct exposure of the injector to the flame can cause combustion products to accumulate on the nozzle, which can result in increased particulate emissions. This research observes the impact of injector fouling on particulate emissions and the associated injector spray pattern and shows how both can be reversed by utilising fuel detergency. For this purpose multi-hole injectors were deliberately fouled in a four-cylinder test engine with two different base fuels. During a fo...

show abstract

Section: Engine Resultsmentioning

confidence: 99%

Section: Engine Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Injector Fouling and Its Impact on Engine Emissions and Spray Characteristics in Gasoline Direct Injection Engines

Henkel

Hardalupas

Taylor

et al. 2017

SAE Int. J. Fuels Lubr.

View full text Add to dashboard Cite

show abstract

“…However in the present study, the effect of LEDI on extending lean burn limit is weaker than that of EEDI. One possible explanation to this result is that LEDI might lead to severe fuel impingement on the piston crown and cylinder wall as reported in [21]. This wall-wetting negatively affects the mixture formation, combustion, decreasing combustion stability (Fig.…”

Section: Elsevier_jfue_8212mentioning

confidence: 95%

“…In this combustion mode, the greater throttle opening reduces the pumping losses associated with stoichiometric conditions at partial engine load. Lean burn can also reduce (nitrogen oxides) NO x emissions which are temperature dependent, and HC emissions which are related to the availability of oxygen [20,21]. However, when the mixture is leaned, the combustion may become unstable.…”

Section: Introductionmentioning

confidence: 99%

Effects of direct injection timing of ethanol fuel on engine knock and lean burn in a port injection gasoline engine

Zhuang

Hong

2014

Fuel

View full text Add to dashboard Cite

Improving engine efficiency and reducing its emissions are the major tasks of recent development in internal combustion technology [1]. This is driven by the society concerns about the global warming and the depletion in supply of fossil fuels. One of the feasible short-to-midterm solutions for addressing the concerns is to use renewable fuels such as ethanol. Many countries and areas have enacted legislations [2] or incentive policies to promote the use of ethanol and other bio/renewable fuels [3,4]. The use of ethanol and other bio/renewable fuels has brought new challenges to automotive sector to develop new technologies. Ethanol direct injection plus gasoline port injection (EDI + GPI) is one of the new technologies in recent development.Previous studies on SI engines found that using ethanol fuel could help to reduce unburned emissions such as carbon monoxide (CO) and hydrocarbon (HC) [5][6][7], enhance engine anti-knock ability [8,9], and improve lean burn performance [10,11]. In the current applications, ethanol is externally blended with gasoline at a specific ratio. The applications of this method decreased pollutant emissions and increased engine efficiency in certain engine conditions [12,13]. However, the vehicles may face problems of reduced vehicle coverage, difficult cold start [14], corrosion and reduced lubrication [15]. Moreover, due to the fixed ethanol/gasoline ratio, the ethanol's potential in reducing engine emissions and improving thermal efficiency cannot be fully exploited. Research has already shown that the optimal ethanol/gasoline ratio for maximizing engine efficiency and minimizing emissions was varied with the engine operation condition [6,7]. EDI + GPI dual-fuel injection, on the other hand, provides an opportunity to solve the problems and meet the requirements. It offers greater flexibility of using ethanol fuel because the ethanol and gasoline mixing ratio can be instantly altered according to the engine operation Effects of direct injection timing of ethanol fuel on engine knock and lean burn in a port injection gasoline engine AbstractEthanol is a promising alternative fuel for internal combustion engines due to its renewable feature. To make the use of ethanol fuel more effective and efficient, ethanol direct injection plus gasoline port injection (EDI + GPI) has been investigated in recent years. By directly injecting ethanol into the engine, the advantages of ethanol fuel such as high latent heat of vaporization, fast laminar flame speed, wide flammability and better low temperature combustion stability can be well utilized to enhance engine anti-knock ability and improve lean burn performance. For an engine equipped with direct injection (DI) system, start of injection (SOI) timing is an important control parameter which directly affects the engine performance. This paper reports the investigation to the effect of ethanol fuel SOI timing on knock mitigation and lean burn. Experiments were conducted on a 250 cc single cylinder spark ignition (SI) engine equipped with EDI ...

show abstract