Experimental investigation into the effects of two-stage injection on fuel injection quantity, combustion and emissions in a high-speed optical common rail diesel engine

Herfatmanesh, Mohammad Reza; Lu, Pin; Attar, Mohammadreza Anbari; Zhao, Hua

doi:10.1016/j.fuel.2013.01.013

Cited by 81 publications

(27 citation statements)

References 26 publications

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“…High-speed imaging is a non-intrusive technique that can give a good physical insight of the processes leading to preignition events and the way this phenomenon evolves in the system. High-speed analyses have been performed in engine cycles [18], rapid compression machines [16,17,19], flames [20] and spray characterization [21]. High-speed OH* chemiluminescence may be related to the rate of heat release of the observed phenomenon [22].…”

Section: Introductionmentioning

confidence: 99%

Shock tube studies of ethanol preignition

Figueroa-Labastida

Badra

Elbaz

et al. 2018

Combustion and Flame

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CitationFigueroa-Labastida M, Badra J, Elbaz AM, Farooq A (2018) Shock tube studies of ethanol preignition. . Available: http://dx. AbstractUnderstanding premature ignition or preignition is of great importance as this phenomenon influences the design and operation of internal combustion engines. Preignition leading to super-knock restricts the efficiency of downsized boosted engines. To gain a fundamental understanding of preignition and how it affects an otherwise homogeneous ignition process, a shock tube may be used to decipher the influence of fuel chemical structure, temperature, pressure, equivalence ratio and bath gas on preignition. In a previous work by Javed et al.[1], ignition delay time measurements of nheptane showed significantly expedited reactivity compared to well-validated chemical kinetic models in the intermediate-temperature regime. In the current work, ethanol is chosen as a representative fuel that, unlike n-heptane, does not exhibit negative temperature coefficient (NTC) behaviour. Reactive mixtures containing 2.9% and 5% of ethanol at equivalence ratios of 0.5 and 1 were used for the measurement of ignition delay times behind reflected shock waves at 2 and 4 bar. Effect of bath gas was studied with mixtures containing either Ar or N2. In addition to conventional side-wall pressure and OH* measurements, a high-speed imaging setup was utilized to visualize the shock tube crosssection through a transparent quartz end-wall. The results suggest that preignition events are more likely to happen in mixtures containing higher ethanol concentration and that preignition energy release is more pronounced at lower temperatures. High-speed imaging shows that low-temperature ignition process is usually initiated from an individual hot spot that grows gradually, while hightemperatures ignition starts from many spots simultaneously which consume the reactive mixture almost homogeneously.

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Section: Introductionmentioning

confidence: 99%

Shock tube studies of ethanol preignition

Figueroa-Labastida

Badra

Elbaz

et al. 2018

Combustion and Flame

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“…Engine performance, fuel economy, and pollutant control have improved dramatically over the last three decades. Nevertheless, there is still interest in further development that warrants a critical and detailed evaluation of the combustion process largely influenced by fuel-air mixing [1,2]. To this end, computational fluid dynamic (CFD) models offer unmatched advantages over experimental approaches due to the large amount of temporal and spatial information they are able to provide.…”

Section: Introductionmentioning

confidence: 99%

The effect of nozzle geometry over internal flow and spray formation for three different fuels

Payri

Viera

Gopalakrishnan

et al. 2016

Fuel

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h i g h l i g h t sTwo single hole nozzle (cylindrical and convergent) are used. A complete hydraulic characterization is done along with spray visualization. A fast pulsed light source is synchronized to a fast camera working at 160 kHz. The effect of nozzle geometry is analyzed for three different fuels. A large set of experimental data was obtained, which could be used for model validation. a b s t r a c tThe influence of internal nozzle flow characteristics over macroscopic spray development is studied experimentally for two different nozzle geometries and three fuels. The measurements include a complete hydraulic characterization consisting of instantaneous injection rate and spray momentum flux measurements, followed by a high-speed visualization of isothermal liquid spray in combination with cylindrical and conical nozzle configurations. Two of the fuels are pure components-n-heptane and ndodecane-while the third fuel consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. The cylindrical nozzle with 8.6% larger diameter, in spite of higher mass flow rate and momentum flux, shows slower spray tip penetration when compared to the conical nozzle. The spreading angle is found to be inversely proportional to the spray tip penetration. The spreading angle is largely influenced by the nozzle geometry and the ambient density. Rail pressure was found to have weak influence on the near-field spreading angle and no influence on the standard deviation of the spreading angle. n-Heptane spray shows slowest penetration rates while n-dodecane and the surrogate fuel mixture show very similar spray behavior for variations in injection pressure and back pressure. However, the surrogate fuel mixture shows higher penetration than n-dodecane when using the conical nozzle and lower penetration than n-dodecane when using cylindrical nozzle.

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“…Biodiesel intends to give better ignition quality though it has slightly lower cetane number than diesel oil. On the other hand, the high injection pressure and small nozzle-hole size provide smaller fuel droplets and faster fuel evaporation in the spray combustion process of liquid fuel, which corresponds to optimize the engine design [18,19]. The present study demonstrates the fuel spray development that is related with the ignition and combustion characteristics.…”

Section: Contents Lists Available At Sciencedirectmentioning

confidence: 70%