Characterization of Ethanol Blends Combustion Processes and Soot Formation in a GDI Optical Engine

Polyoxymethylene dimethyl ethers (PODE) are a newly appeared promising oxygenated alternative that can greatly reduce soot emissions of diesel engines. The combustion characteristics of the PODE and diesel blends (the blending ratios of PODE are 0%, 20%, 50% and 100% by volume, respectively) are investigated based on an optical engine under the injection timings of 6, 9, 12 and 15-degree crank angles before top dead center and injection pressures of 100 MPa, 120 MPa and 140 MPa in this study. The results show that both the ignition delay and combustion duration of the fuels decrease with the increasing of PODE ratio in the blends. However, in the case of the fuel supply of the optical engine being fixed, the heat release rate, cylinder pressure and temperature of the blend fuels decrease with the PODE addition due to the low lower heating value of PODE. The addition of PODE in diesel can significantly reduce the integrated natural flame luminosity and the soot formation under all injection conditions. When the proportion of the PODE addition is 50% and 100%, the chemical properties of the blends play a leading role in soot formation, while the change of the injection conditions have an inconspicuous effect on it. When the proportion of the PODE addition is 20%, the blend shows excellent characteristics in a comprehensive evaluation of combustion and soot reduction.

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Experimental characterization of the different nitrogen dilution effects on soot formation in ethylene diffusion flames

Proceedings of the Combustion Institute ◽

10.1016/j.proci.2016.07.063 ◽

2017 ◽

Vol 36 (2) ◽

pp. 3227-3235 ◽

Cited By ~ 12

Author(s):

Q. Wang ◽

G. Legros ◽

J. Bonnety ◽

C. Morin

Keyword(s):

Diffusion Flames ◽

Soot Formation ◽

Experimental Characterization ◽

Nitrogen Dilution ◽

Dilution Effects

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Proton NMR characterization of gasoline–ethanol blends

Fuel ◽

10.1016/j.fuel.2014.08.018 ◽

2014 ◽

Vol 137 ◽

pp. 335-338 ◽

Cited By ~ 7

Author(s):

A. Turanov ◽

A.K. Khitrin

Keyword(s):

Proton Nmr ◽

Nmr Characterization ◽

Ethanol Blends

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Investigation of Swirl Ratio Impact on In-Cylinder Flow in a SIDI Optical Engine

Volume 1: Large Bore Engines; Fuels; Advanced Combustion ◽

10.1115/icef2015-1160 ◽

2015 ◽

Author(s):

Hanyang Zhuang ◽

David L. S. Hung ◽

Jie Yang ◽

Shaoxiong Tian

Keyword(s):

Flow Field ◽

Soot Formation ◽

Flow Characteristics ◽

Control Valve ◽

Exhaust Emission ◽

Swirl Ratio ◽

Optical Engine ◽

Crank Angle ◽

Cylinder Flow ◽

Intake Swirl

Advanced powertrain technologies have improved engine performance with higher power output, lower exhaust emission, and better controllability. Chief among them is the development of spark-ignition direct-injection (SIDI) engines in which the in-cylinder processes control the air flow motion, fuel-air mixture formation, combustion, and soot formation. Specifically, intake air with strong swirl motion is usually introduced to form a directional in-cylinder flow field. This approach improves the mixing process of air and fuel as well as the propagation of flame. In this study, the effect of intake air swirl on in-cylinder flow characteristics was experimentally investigated. High speed particle image velocimetry (PIV) was conducted in an optical SIDI engine to record the flow field on a swirl plane. The intake air swirl motion was achieved by adjusting the opening of a swirl ratio control valve which was installed in one of the two intake ports in the optical engine. Ten opening angles of the swirl ratio control valve were adjusted to produce an intake swirl ratio from 0.55 to 5.68. The flow structures at the same crank angle degree, but under different swirl ratio, were compared and analyzed using proper orthogonal decomposition (POD). The flow dominant structures and variation structures were interpreted by different POD modes. The first POD mode captured the most dominant flow field structure characteristics; the corresponding mode coefficients showed good linearity with the measured swirl ratio at the compression stroke when the flow was swirling and steady. During the intake stroke, strong intake air motion took place, and the structures and coefficients of the first modes varied along different swirl ratio. These modes captured the flow properties affected by the intake swirl motion. Meanwhile, the second and higher modes captured the variation feature of the flow at various crank angle degrees. In summary, this paper demonstrated a promising approach of using POD to interpret the effectiveness of swirl control valve on in-cylinder swirl flow characteristics, providing better understanding for engine intake system design and optimization.

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Measuring the effectiveness of high-performance Co-Optima biofuels on suppressing soot formation at high temperature

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1920223117 ◽

2020 ◽

Vol 117 (7) ◽

pp. 3451-3460 ◽

Cited By ~ 6

Author(s):

Samuel Barak ◽

Ramees K. Rahman ◽

Sneha Neupane ◽

Erik Ninnemann ◽

Farhan Arafin ◽

...

Keyword(s):

High Temperature ◽

Shock Tube ◽

High Performance ◽

High Efficiency ◽

Soot Formation ◽

Diagnostic Techniques ◽

Department Of Energy ◽

Negative Consequences ◽

Shock Heating ◽

Combustion Processes

Soot emissions in combustion are unwanted consequences of burning hydrocarbon fuels. The presence of soot during and following combustion processes is an indication of incomplete combustion and has several negative consequences including the emission of harmful particulates and increased operational costs. Efforts have been made to reduce soot production in combustion engines through utilizing oxygenated biofuels in lieu of traditional nonoxygenated feedstocks. The ongoing Co-Optimization of Fuels and Engines (Co-Optima) initiative from the US Department of Energy (DOE) is focused on accelerating the introduction of affordable, scalable, and sustainable biofuels and high-efficiency, low-emission vehicle engines. The Co-Optima program has identified a handful of biofuel compounds from a list of thousands of potential candidates. In this study, a shock tube was used to evaluate the performance of soot reduction of five high-performance biofuels downselected by the Co-Optima program. Current experiments were performed at test conditions between 1,700 and 2,100 K and 4 and 4.7 atm using shock tube and ultrafast, time-resolve laser absorption diagnostic techniques. The combination of shock heating and nonintrusive laser detection provides a state-of-the-art test platform for high-temperature soot formation under engine conditions. Soot reduction was found in ethanol, cyclopentanone, and methyl acetate; conversely, an α-diisobutylene and methyl furan produced more soot compared to the baseline over longer test times. For each biofuel, several reaction pathways that lead towards soot production were identified. The data collected in these experiments are valuable information for the future of renewable biofuel development and their applicability in engines.

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Soot Formation in Combustion Processes (Review)

Combustion Explosion and Shock Waves ◽

10.1007/s10573-005-0083-2 ◽

2005 ◽

Vol 41 (6) ◽

pp. 727-744 ◽

Cited By ~ 101

Author(s):

Z. A. Mansurov

Keyword(s):

Soot Formation ◽

Combustion Processes

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Mathematical Modelling of Particle Formation in Combustion Processes

Volume 4: Fatigue and Fracture, Heat Transfer, Internal Combustion Engines, Manufacturing, and Technology and Society ◽

10.1115/esda2006-95407 ◽

2006 ◽

Author(s):

Alessandro Zucca ◽

Daniele L. Marchisio ◽

Antonello A. Barresi ◽

Giancarlo Baldi

Keyword(s):

Soot Formation ◽

Global Climate ◽

Population Balance ◽

Scalar Fields ◽

Particle Formation ◽

Turbulent Flames ◽

Morphological Properties ◽

Navier Stokes ◽

Size And Morphology ◽

Combustion Processes

In recent years the problem of studying particle formation and evolution in turbulent flames has become increasingly important, for both environmental and technological reasons. Information on particle size and morphology is often required, since these characteristics largely influence the effects of particulate matter on human health and global climate in the case of soot. A mathematical model able to describe the evolution of these particulate systems must solve the population balance equation within a Computational Fluid Dynamics (CFD) code that predicts the temperature, composition and velocity fields of the flame. In this work, the recently proposed Direct Quadrature Method of Moments (DQMOM) is applied to the study of soot formation in turbulent non-premixed flames. The model takes into account nucleation, molecular growth, oxidation and aggregation of soot particles; simplified kinetic rates are employed, while velocity and scalar fields are computed by simulations based on the solution of the Reynolds Averaged Navier Stokes (RANS) equations. Different population balance formulations are implemented and compared and results show that DQMOM is a suitable modelling tool; comparison of predictions with experimental data shows that the model accurately describes the morphological properties of soot aggregates.

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