Experimental study on the combustion characteristics of emulsified diesel in a rapid compression and expansion machine

2000 ◽  
Vol 214 (5) ◽  
pp. 579-586 ◽  
Author(s):  
J. W. Park ◽  
K. Y. Huh ◽  
K. H. Park
Keyword(s):  
High Speed ◽  
Flame Temperature ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Test Cases ◽  
Diesel Fuels ◽  
Fuel Droplets ◽  
Pressure Trace ◽  
Compression And Expansion ◽  
Rapid Compression

The combustion characteristics of emulsified diesel fuels are investigated in a rapid compression and expansion machine (RCEM). Among the test cases, the 40 water-oil (W/O) fuel injected at 20° before top dead center (BTDC) has shown the best performance with respect to efficiency and NOx and soot emissions. The pressure trace of the 40 W/O fuel is characterized by a longer ignition delay and a lower rate of pressure rise in premixed combustion. High-speed photographs show reduced flame luminosity and lower flame temperature with increasing W/O ratio. Microexplosions of emulsified fuel droplets, which affect the local shape and brightness of the flame, are identified in magnified flame images.

An Investigation on the Ignition Characteristics of Lubricant Component Containing Fuel Droplets Using Rapid Compression and Expansion Machine

2016 ◽  
Vol 9 (3) ◽  
pp. 469-480 ◽  
Author(s):  
Masaharu Kassai ◽  
Taisuke Shiraishi ◽  
Toru Noda ◽  
Mamoru Hirabe ◽  
Yoshiki Wakabayashi ◽  
...  
Keyword(s):  
Fuel Droplets ◽  
Compression And Expansion ◽  
Rapid Compression ◽  
Ignition Characteristics

Combustion Characteristics of Diesel Spray Under Low O2 Concentration Condition

2013 ◽  
Author(s):  
Akihiko Azetsu ◽  
Youhei Nagashima ◽  
Kei Yamamoto
Keyword(s):  
Heat Release ◽  
High Speed ◽  
Light Emission ◽  
Flame Temperature ◽  
Video Camera ◽  
Temporal Variations ◽  
Combustion Characteristics ◽  
Oh Radicals ◽  
Experimental Apparatus ◽  
O2 Concentration

The spray combustion of diesel fuel under conditions of very low ambient O2 concentrations was examined in this study. The detailed combustion characteristics were evaluated using two different sets of experimental apparatuses. A high-temperature, high-pressure combustion vessel with dual observation windows was employed to visualize the spray flame. The sequential images were obtained by using a high-speed color video camera and were analyzed using the two color method to quantify the temporal variation of the two dimensional distribution of soot temperature and KL factor. Both the ambient O2 concentration and the CO2 mixing ratio were varied as experimental parameters. A second constant volume vessel with a smaller internal volume was also employed as an experimental apparatus to conduct analyses of heat release rates based on temporal variations of pressure. Based on a series of systematic experiments, we confirmed that O2 concentration is the primary factor affecting both the ignition delay and combustion period, while the level of CO2 mixing has little effect. Decreasing O2 concentrations were associated with delays in the appearance of the luminous flame following the onset of light emission from OH radicals. The heat release rate study showed the possibility of the existence of endothermic reactions during this period. The flame temperature was observed to decrease as the O2 concentration decreased and as the CO2 ratio increased, resulting in reduced NOx emissions. The amount of soot inside the flame initially increased with decreasing O2 concentrations, but then decreased starting at an O2 concentration of approximately 11%, such that minimal amounts of soot were generated at very low O2 levels. Both visual observations and emissions measurements confirmed that the simultaneous reduction of NOx, soot and CO can be successfully achieved under very low O2 concentrations.

Combustion Characteristics and Laminar Flame Speed of Premixed Ethanol-Air Mixtures with Laser-Induced Spark Ignition

2017 ◽  
Vol 2 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Cangsu Xu ◽  
Anhao Zhong ◽  
Chongming Wang ◽  
Chaozhao Jiang ◽  
Xiaolu Li ◽  
...  
Keyword(s):  
High Speed ◽  
Laminar Flame ◽  
Pressure Rise ◽  
Spark Ignition ◽  
Laser Wavelength ◽  
Combustion Characteristics ◽  
Flame Speed ◽  
Maximum Pressure ◽  
Laminar Flame Speed ◽  
Combustion Duration

AbstractLaser-induced spark-ignition (LISI) has an advanced ignition technique with a few benefits over spark ignition. In this study, flame morphology, laminar flame characteristics and combustion characteristics of premixed anhydrous ethanol and air mixtures were investigated using LISI generated by a Q-switched Nd: YAG laser (wavelength: 1064 nm). Experiments were conducted in a constant volume combustion chamber (CVCC) at the initial condition of T0=358 K and P0=0.1 MPa, respectively, and with equivalence ratios (ɸ) of 0.6-1.6. Flame images were recorded by using the high-speed Schlieren photography technique, and the in-vessel pressure was recorded using a piezoelectric pressure transducer. Tests were also carried out with spark ignition, and the results were used as a reference. It has been found that the laminar flame speed of ethanol-air mixtures with LISI was comparable with those of spark ignition, proving that ignition methods have no influence on laminar flame speed which is an inherent characteristic of a fuel-air mixture. The peak laminar burning velocities for LISI and spark ignition with nonlinear extrapolation methods were approximately 50 cm/s at ɸ=1.1. However, LISI was able to ignite leaner mixtures than spark ignition. The maximum pressure rise rate of LISI was consistently higher than that of spark ignition at all tested ɸ, although the maximum pressure was similar for LISI and spark ignition. The initial combustion duration and main combustion duration reached the minimum at ɸ=1.1.

Study of prechamber combustion characteristics in a rapid compression and expansion machine

2017 ◽  
Vol 115 ◽  
pp. 64-71 ◽  
Author(s):  
Kimitoshi Tanoue ◽  
Takanori Kimura ◽  
Taishu Jimoto ◽  
Jun Hashimoto ◽  
Yasuo Moriyoshi
Keyword(s):  
Combustion Characteristics ◽  
Compression And Expansion ◽  
Rapid Compression

Comparison between Flat and Creviced Pistons in a Controlled Trajectory Rapid Compression and Expansion Machine (CT-RCEM)

2021 ◽  
Author(s):  
Krishna Chandra C. Bavandla ◽  
Abhinav Tripathi ◽  
Dezhi Zhou ◽  
Zongxuan Sun ◽  
Suo Yang
Keyword(s):  
Compression And Expansion ◽  
Rapid Compression
Sign in / Sign up

Export Citation Format

Share Document