scholarly journals Experimental Study of the Effect of Hydrotreated Vegetable Oil and Oxymethylene Ethers on Main Spray and Combustion Characteristics under Engine Combustion Network Spray A Conditions

2020 ◽  
Vol 10 (16) ◽  
pp. 5460
Author(s):  
José V. Pastor ◽  
José M. García-Oliver ◽  
Carlos Micó ◽  
Alba A. García-Carrero ◽  
Arantzazu Gómez
Keyword(s):  
Vegetable Oil ◽  
Diesel Fuel ◽  
Ignition Delay ◽  
Soot Formation ◽  
Imaging Techniques ◽  
Detection Threshold ◽  
Combustion Characteristics ◽  
Engine Combustion ◽  
Lift Off ◽  
Oxygenated Fuels

The stringent emission regulations have motivated the development of cleaner fuels as diesel surrogates. However, their different physical-chemical properties make the study of their behavior in compression ignition engines essential. In this sense, optical techniques are a very effective tool for determining the spray evolution and combustion characteristics occurring in the combustion chamber. In this work, quantitative parameters describing the evolution of diesel-like sprays such as liquid length, spray penetration, ignition delay, lift-off length and flame penetration as well as the soot formation were tested in a constant high pressure and high temperature installation using schlieren, OH∗ chemiluminescence and diffused back-illumination extinction imaging techniques. Boundary conditions such as rail pressure, chamber density and temperature were defined using guidelines from the Engine Combustion Network (ECN). Two paraffinic fuels (dodecane and a renewable hydrotreated vegetable oil (HVO)) and two oxygenated fuels (methylal identified as OME1 and a blend of oxymethylene ethers, identified as OMEx) were tested and compared to a conventional diesel fuel used as reference. Results showed that paraffinic fuels and OMEx sprays have similar behavior in terms of global combustion metrics. In the case of OME1, a shorter liquid length, but longer ignition delay time and flame lift-off length were observed. However, in terms of soot formation, a big difference between paraffinic and oxygenated fuels could be appreciated. While paraffinic fuels did not show any significant decrease of soot formation when compared to diesel fuel, soot formed by OME1 and OMEx was below the detection threshold in all tested conditions.

Spray Combustion Characteristics of Single/Multi-Component Surrogate Fuel for Aviation Kerosene

2022 ◽  
Author(s):  
Wenjin Qin ◽  
Dengbiao Lu ◽  
Lihui Xu
Keyword(s):  
Soot Formation ◽  
Mean Field ◽  
Combustion Characteristics ◽  
Spray Combustion ◽  
Aviation Kerosene ◽  
Eddy Simulation ◽  
Air Mixing ◽  
Flow Field Characteristics ◽  
Lift Off ◽  
Surrogate Fuel

Abstract In this research, n-dodecane and JW are selected as single and multi-component surrogate fuel of aviation kerosene to study the Jet-A spray combustion characteristics. The spray combustion phenomena are simulated using large eddy simulation coupled with detailed chemical reaction mechanism. Proper orthogonal decomposition method is applied to analyze the flow field characteristics, and the instantaneous velocity field are decomposed into four parts, namely the mean field, coherent field, transition field and turbulent field, respectively. The four subfields have their own characteristics. In terms of different fuels, JW has a higher intensity of coherent structures and local vortices than n-dodecane, which promotes the fuel-air mixing and improves the combustion characteristics, and the soot formation is significantly reduced. In addition, with the increase of initial temperature, the combustion is more intense, the ignition delay time is advanced, the flame lift-off length is reduced, and soot formation is increased accordingly.

Shock tube studies on ignition delay and combustion characteristics of oxygenated fuels under high temperature

2020 ◽  
Vol 44 (13) ◽  
pp. 10101-10111 ◽  
Author(s):  
Zhihao Ma ◽  
Weixin Du ◽  
Xin Wang ◽  
Enyu Lv ◽  
Yongchao Dong
Keyword(s):  
High Temperature ◽  
Shock Tube ◽  
Ignition Delay ◽  
Combustion Characteristics ◽  
Oxygenated Fuels

Assessment of engine combustion network recommendations for measurement of ignition and lift-off length

2020 ◽  
pp. 146808742092264
Author(s):  
Boni F Yraguen ◽  
Farzad Poursadegh ◽  
Caroline L Genzale
Keyword(s):  
Ignition Delay ◽  
High Speed ◽  
Operating Conditions ◽  
Bias Error ◽  
Ambient Conditions ◽  
Intensity Histogram ◽  
Wide Range ◽  
Engine Combustion ◽  
Length Measurements ◽  
Lift Off

The engine combustion network recommends two different imaging-based diagnostics for the measurement of diesel spray ignition delay and lift-off length, respectively. To measure ignition delay, high-speed imaging of broadband luminosity, spectrally filtered to limit collected wavelengths below 600 nm, is recommended. This diagnostic is often referred to as broadband natural luminosity. For lift-off length measurements, the engine combustion network recommends imaging of OH* chemiluminescence. This diagnostic requires using an image-intensified camera to detect narrowly filtered light around 310 nm. Alternatively, it has been shown that the lift-off length can be measured using broadband natural luminosity, avoiding the need for an intensifier and ultraviolet-transmitting optics. However, care is needed in the collection and processing of this diagnostic to accurately isolate the chemiluminescence signal. Particularly, standard intensity thresholding techniques are not sufficient for isolating the chemiluminescence signal in broadband natural luminosity images. Thus, an intensity-histogram-based thresholding method is introduced. This article assesses the feasibility and practicality of measuring lift-off length using broadband natural luminosity using a detailed comparison to OH* chemiluminescence measurements. It is shown that lift-off length measurements using broadband natural luminosity are prone to user bias error in the optical setup and data processing, especially under moderate- to high-sooting conditions. We conclude that while OH* imaging provides the most reliable and accurate measurement of lift-off length at a wide range of ambient conditions, an intensity-histogram analysis can help discriminate the high-temperature chemiluminescence signal from others in a broadband natural luminosity image at higher-sooting operating conditions than demonstrated in current literature.

Renewable Fuel Performance in a Legacy Military Diesel Engine

2011 ◽  
Author(s):  
Leonard J. Hamilton ◽  
Sherry A. Williams ◽  
Richard A. Kamin ◽  
Matthew A. Carr ◽  
Patrick A. Caton ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Vegetable Oil ◽  
Ignition Delay ◽  
Jet Fuel ◽  
Combustion Characteristics ◽  
Load Range ◽  
Engine Torque ◽  
Brake Torque ◽  
Renewable Fuel

A new Hydrotreated Vegetable Oil (HVO) from the camelina plant has been processed into a Hydrotreated Renewable Jet (HRJ) fuel. This HRJ fuel was tested in an extensively instrumented legacy military diesel engine along with conventional Navy jet fuel JP-5. Both fuels performed well across the speed-load range of this HMMWV engine. The high cetane value of the HRJ leads to modestly shorter ignition delay. The longer ignition delay of JP-5 delivers shorter overall combustion durations, with associated higher indicated engine torque levels. Both brake torque and brake fuel consumption are better with conventional JP-5 by up to ten percent, due to more ideal combustion characteristics.

Investigation on the spray development, the combustion characteristics and the emissions of Fischer–Tropsch fuel and diesel fuel from direct coal liquefaction

2017 ◽  
Vol 231 (13) ◽  
pp. 1829-1837 ◽  
Author(s):  
Yiqiang Pei ◽  
Jing Qin ◽  
Yuli Dai ◽  
Kun Wang
Keyword(s):  
Diesel Fuel ◽  
Ignition Delay ◽  
Cetane Number ◽  
Combustion Process ◽  
Physicochemical Characteristics ◽  
Combustion Characteristics ◽  
Coal Liquefaction ◽  
Fischer Tropsch ◽  
Planar Laser ◽  
Direct Coal Liquefaction

Diesel fuel is largely consumed by transportation services, and diesel fuel from direct coal liquefaction and Fischer–Tropsch fuel have been produced as alternatives in coal-rich areas. However, the physicochemical characteristics of the two fuels are not quite the same as those of diesel fuel derived from crude oil. Therefore, the spray development, the combustion characteristics and the emissions of diesel fuel from direct coal liquefaction, Fischer–Tropsch fuel and commercial diesel fuel were studied in this paper. The spray development was investigated by using planar laser-induced fluorescence, and the results showed that the spray characteristics of coal-liquefied fuel were similar to those of commercial diesel fuel. Diesel fuel from direct coal liquefaction has a longer ignition delay and a higher heat release rate from premixed combustion than commercial diesel fuel does because of its lower cetane number at low loads. However, the same combustion characteristics with commercial diesel fuel can be achieved by mixing diesel fuel from direct coal liquefaction and Fischer–Tropsch fuel in a ratio of 3 to 1. With increasing engine load, the in-cylinder temperature and the pressure increased which reduced the effect of the cetane number on the ignition delay and the combustion process. The regulated emissions from Fischer–Tropsch fuel were the lowest of these fuels; the unregulated emissions measured by Fourier transform infrared spectroscopy, however, were slightly higher than those of the other two fuels.

Flame lift-off length and soot production of oxygenated fuels in relation with ignition delay in a DI heavy-duty diesel engine

2011 ◽  
Vol 158 (3) ◽  
pp. 525-538 ◽  
Author(s):  
A.J. Donkerbroek ◽  
M.D. Boot ◽  
C.C.M. Luijten ◽  
N.J. Dam ◽  
J.J. ter Meulen
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Heavy Duty ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Lift Off ◽  
Oxygenated Fuels
Sign in / Sign up

Export Citation Format

Share Document