scholarly journals High-Speed Imaging of Spray Formation and Combustion in an Optical Engine: Effects of Injector Aging and TPGME as a Fuel Additive

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3105
Author(s):  
Xinda Zhu ◽  
Manu Mannazhi ◽  
Natascia Palazzo ◽  
Per-Erik Bengtsson ◽  
Öivind Andersson
Keyword(s):  
High Speed ◽  
Combustion Process ◽  
Soot Oxidation ◽  
Monomethyl Ether ◽  
Mie Scattering ◽  
Fuel Additive ◽  
High Speed Imaging ◽  
Spray Formation ◽  
Optical Engine ◽  
Injection Quantity

High-speed imaging of fuel sprays and combustion is conducted on a light-duty optical engine to investigate the effects of injector aging, with a focus on soot. The spray behaviors of one new and one aged injector are compared using Mie-scattering. In addition to this, the combustion process of a baseline diesel fuel and a blend with TPGME (tripropylene glycol monomethyl ether) are compared using natural luminosity (NL) imaging. TPGME is an oxygenated additive which can be used to reduce soot emissions. X-ray tomography of the two injectors demonstrates that the aging does not lead to significant geometry differences, nor to formation of dense internal nozzle deposits. Both injectors show similar liquid penetration and spreading angle. However, the aged injector shows a prolonged injection and more fuel dribbling after the injection events, leading to a higher injection quantity. The fuel quantity difference shows a larger impact on the NL at low load than the TPGME additive, indicating that the in-cylinder temperature is more important for soot oxidation than oxygen concentration under these conditions. At medium load, the NL is much less sensitive to small temperature variations, while the TPGME is more effective for soot reduction.

Effect of Pilot Injection on Diesel Knock in a Small-Bore Optical Engine

2012 ◽  
Author(s):  
Alvin M. Rusly ◽  
Sanghoon Kook ◽  
Evatt R. Hawkes ◽  
Renlin Zhang
Keyword(s):  
High Speed ◽  
Pressure Rise ◽  
Pilot Injection ◽  
Cylinder Pressure ◽  
High Speed Imaging ◽  
Term Operation ◽  
Optical Engine ◽  
Injection Duration ◽  
Rise Rate ◽  
Main Injection

Diesel knock is a phenomenon that generates undesirable noise and vibration that can be destructive to diesel engine structures and components for long-term operation. The diesel knock occurs when a large quantity of air-fuel is mixed prior to combustion when the ignition delay is long. This leads to a drastic pressure rise during the premixed phase of the combustion, which is followed by a pressure ringing. The main focus of this study is to examine effect of pilot injection on the pressure ringing and associated in-cylinder flame behaviour. In a single-cylinder small-bore optical engine, in-cylinder pressure measurement and high-speed imaging of the natural combustion luminosity have been performed. Results demonstrate that pilot injection helps reduce the in-cylinder pressure ringing by reducing the pressure rise rate of the main injection. Moreover, oscillation of the flames observed during the knocking events appears to diminish when the pilot injection is applied. How the pilot injection duration and timing affect the diesel knock behaviour is also discussed in detail.

scholarly journals A Comparison of Methyl Decanoate and Tripropylene Glycol Monomethyl Ether for Soot-Free Combustion in an Optical Direct-Injection Diesel Engine

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Cosmin E. Dumitrescu ◽  
A. S. Cheng ◽  
Eric Kurtz ◽  
Charles J. Mueller
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Soot Formation ◽  
Monomethyl Ether ◽  
Mie Scattering ◽  
Compression Ignition Engine ◽  
Glycol Monomethyl Ether ◽  
Soot Emissions ◽  
Lift Off ◽  
Methyl Decanoate

Oxygenated fuels have beneficial effects for leaner lifted-flame combustion (LLFC), a nonsooting mode of mixing-controlled combustion associated with lift-off length equivalence ratios below approximately 2. A single-cylinder heavy-duty optical compression-ignition engine was used to compare neat methyl decanoate (MD) and T50, a 50/50 blend by volume of tripropylene glycol monomethyl ether (TPGME) and #2 ultralow sulfur emissions-certification diesel fuel (CF). High-speed, simultaneous imaging of natural luminosity (NL) and chemiluminescence (CL) were employed to investigate the ignition, combustion, and soot formation/oxidation processes at two injection pressures and three dilution levels. Additional Mie scattering measurements observed fuel-property effects on the liquid length of the injected spray. Results indicate that both MD and T50 effectively eliminated engine-out smoke emissions by decreasing soot formation and increasing soot oxidation during and after the end of fuel injection. MD further reduced soot emissions by 50–90% compared with T50, because TPGME could not completely compensate for the aromatics in the CF. Despite the low engine-out soot emissions, both fuels produced in-cylinder soot because the equivalence ratio at the lift-off length never reached the nonsooting limit. With respect to the other engine-out emissions, T50 had up to 16% higher nitrogen oxides (NOx) emissions compared with MD, but neither fuel showed the traditional soot-NOx trade-off associated with conventional mixing-controlled combustion. In addition, T50 had up to 15% and 26% lower unburned hydrocarbons (HC) and CO emissions, respectively, compared with MD.

A Comparison of Methyl Decanoate and Tripropylene Glycol Monomethyl Ether for Soot-Free Combustion in an Optical Direct-Injection Diesel Engine

2016 ◽  
Author(s):  
Cosmin E. Dumitrescu ◽  
A. S. (Ed) Cheng ◽  
Eric Kurtz ◽  
Charles J. Mueller
Keyword(s):  
High Speed ◽  
Soot Formation ◽  
Monomethyl Ether ◽  
Mie Scattering ◽  
Compression Ignition Engine ◽  
Glycol Monomethyl Ether ◽  
Soot Emissions ◽  
Lift Off ◽  
Oxygenated Fuels ◽  
Methyl Decanoate

Oxygenated fuels have been reported to have beneficial effects for leaner lifted-flame combustion (LLFC), a non-sooting mode of mixing-controlled combustion associated with lift-off length equivalence ratios below approximately 2. A single-cylinder heavy-duty optical compression-ignition engine was used to compare two oxygenated fuels: neat methyl decanoate (MD) and T50, a 50/50 blend by volume of tripropylene glycol monomethyl ether (TPGME) and #2 ultra-low sulfur emissions-certification diesel fuel (CF). High-speed, simultaneous imaging of natural luminosity and chemiluminescence were employed to investigate the ignition, combustion, and soot formation/oxidation processes at two injection pressures and three dilution levels. Additional Mie scattering measurements were employed to observe fuel-property effects on the liquid length of the injected spray. Results indicate that both MD and T50 reduced considerably the engine-out smoke emissions by decreasing soot formation and/or increasing soot oxidation during and after the end of fuel injection. MD further reduced soot emissions by 50–90% compared with T50, because TPGME could not completely compensate for the aromatics in the CF. Despite the low engine-out soot emissions, both fuels produced in-cylinder soot because the equivalence ratio at the lift-off length never reached the non-sooting limit. With respect to the other engine-out emissions, T50 had up to 16% higher NOx emissions compared with MD, but neither fuel showed the traditional soot-NOx trade-off associated with conventional mixing-controlled combustion. In addition, T50 had up to 15% and 26% lower unburned hydrocarbons (HC) and carbon monoxide (CO) emissions, respectively, compared with MD.

Ultra-high speed imaging and OH-LIF study of DMF and MF combustion in a DISI optical engine

2014 ◽  
Vol 122 ◽  
pp. 247-260 ◽  
Author(s):  
Xiao Ma ◽  
Hongming Xu ◽  
Changzhao Jiang ◽  
Shijin Shuai
Keyword(s):  
High Speed ◽  
High Speed Imaging ◽  
Optical Engine ◽  
Ultra High Speed ◽  
Ultra High Speed Imaging

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

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