Effects of Fuel Overpenetration and Overmixing During Ignition-Delay Period on Hydrocarbon Emissions From a Small Open-Chamber Diesel Engine

1988 ◽  
Vol 110 (3) ◽  
pp. 453-461 ◽  
Author(s):  
T.-W. Kuo ◽  
K.-J. Wu ◽  
S. Henningsen
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Swirling Flow ◽  
Delay Period ◽  
Injection Velocity ◽  
Spray Penetration ◽  
Hc Emissions ◽  
Start Of Combustion ◽  
Ignition Delay Period

A quasi-steady gas-jet model was applied to examine the spray trajectory in swirling flow during the ignition-delay period in an open-chamber diesel engine timed to start combustion at top dead center. Spray penetration, deflection, and the fractions of too-lean-mixed, burnable, and overpenetrated fuel at the start of combustion were calculated by employing the measured ignition delay and mean fuel-injection velocity. The calculated parameters were applied to correlate the measured exhaust hydrocarbon (HC) emissions. The engine parameters examined were bowl geometry, compression ratio, overall air-fuel ratio, and speed. Both the ignition delay and the relative spray-penetration parameter, defined as the ratio of the spray-penetration distances at the moments of start of combustion and wall impingement, gave good correlations for some of the engine parameters examined but could not explain all the measured trends. However, good correlation of the measured exhaust HC emissions was obtained by using the calculated too-lean-mixed and overpenetrated fuel fractions at the start of combustion. Correlation of the overpenetrated fuel with the measured HC indicated that approximately 2 percent of the fuel mass that overpenetrated before start of combustion emitted from the engine as unburned HC. This could account for 0 to 65 percent of the total HC emission from this engine. Additionally, it was found that the too-lean-mixed fuel could contribute 10 to 30 percent of the total HC emission, as found in a previous study on a somewhat similar engine. The remaining HC emission is caused by other sources such as bulk quenching.

scholarly journals MODELING OF IGNITION DELAY PERIOD IN DIESEL ENGINE

2019 ◽  
Vol 0 (1) ◽  
pp. 34-38
Author(s):  
А. П. Марченко ◽  
І. В. Парсаданов ◽  
А. В. Савченко
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Delay Period ◽  
Ignition Delay Period

Ignition Delay Period of Jojoba Diesel Engine Fuel

1997 ◽  
Author(s):  
M. S. Radwan ◽  
S. K. Dandoush ◽  
M. Y. E. Selim ◽  
A. M. A. Kader
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Delay Period ◽  
Engine Fuel ◽  
Ignition Delay Period

Effect of Inlet Air Temperature on Auto-Ignition of Fuels With Different Cetane Number and Volatility

2011 ◽  
Author(s):  
Chandrasekharan Jayakumar ◽  
Ziliang Zheng ◽  
Umashankar M. Joshi ◽  
Walter Bryzik ◽  
Naeim A. Henein ◽  
...  
Keyword(s):  
Air Temperature ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Cetane Number ◽  
Delay Period ◽  
Inlet Temperature ◽  
Ignition Process ◽  
Ultra Low Sulfur Diesel ◽  
Auto Ignition ◽  
Ignition Delay Period

This paper investigates the effect of air inlet temperature on the auto-ignition of fuels that have different CN and volatility in a single cylinder diesel engine. The inlet air temperature is varied over a range of 30°C to 110°C. The fuels used are ultra-low-sulfur-diesel (ULSD), JP-8 (two blends with CN 44.1 & 31) and F-T SPK. Detailed analysis is made of the rate of heat release during the ignition delay period, to determine the effect of fuel volatility and CN on the auto-ignition process. A STAR-CD CFD model is applied to simulate the spray behavior and gain more insight into the processes that immediately follow the fuel injection including evaporation, start of exothermic reactions and the early stages of combustion. The mole fractions of different species are determined during the ignition delay period and their contribution in the auto-ignition process is examined. Arrhenius plots are developed to calculate the global activation energy for the auto-ignition reactions of these fuels. Correlations are developed for the ID and the mean air temperature and pressure.

scholarly journals Experimental Study of the Effect of Intake Oxygen Concentration on Engine Combustion Process and Hydrocarbon Emissions with N-Butanol-Diesel Blended Fuel

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1310 ◽  
Author(s):  
Wei Tian ◽  
Yunlu Chu ◽  
Zhiqiang Han ◽  
Xiang Wang ◽  
Wenbin Yu ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Ignition Delay ◽  
Cetane Number ◽  
Combustion Process ◽  
Delay Period ◽  
Blended Fuel ◽  
The Difference ◽  
Hc Emissions ◽  
Oxygen Medium ◽  
Ignition Delay Period

This paper summarizes a study based on a modified, light, single-cylinder diesel engine and the effects of the physicochemical properties for n-butanol-diesel blended fuel on the combustion process and hydrocarbon (HC) emissions in the intake at a medium speed and moderate load in, an oxygen-rich environment (Coxy = 20.9–16%), an oxygen-medium environment (Coxy = 16–12%), and an oxygen-poor environment (Coxy = 12–9%). The results show that the ignition delay period is the main factor affecting the combustion process and it has a decisive influence on HC emissions. In an oxygen-medium environment, combustion duration affected by the cetane number is the main reason for the difference in HC emissions between neat diesel fuel (B00) and diesel/n-butanol blended fuel (B20), and its influence increases as the intake oxygen concentration decreases. In an oxygen-poor environment, in-cylinder combustion temperature affected by the latent heat of vaporization is the main reason for the difference in HC emissions between B00 and B20 fuels, and its influence increases as the intake oxygen concentration decreases. By comparing B20 fuel with diesel/n-butanol/2-ethylhexyl nitrate blended fuel (B20 + EHN), the difference in the ignition delay period caused by the difference in the cetane number is the main reason for the difference in HC emissions between B20 and B20 + EHN fuels in oxygen-poor environment, and the effect of this influencing factor gradually increases as the intake oxygen concentration decreases.

scholarly journals An Examination of the Ignition Delay Period in Gas-Fueled Diesel Engines

1998 ◽  
Vol 120 (1) ◽  
pp. 225-231 ◽  
Author(s):  
Z. Liu ◽  
G. A. Karim
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Chemical Processes ◽  
Delay Period ◽  
Dual Fuel ◽  
Gaseous Fuels ◽  
Gas Fueled ◽  
Fuel Mixtures ◽  
Physical And Chemical ◽  
Ignition Delay Period

Changes in the physical and chemical processes during the ignition delay period of a gas-fueled diesel engine (dual-fuel engine) due to the increased admission of the gaseous fuels and diluents are examined. The extension to the chemical aspects of the ignition delay with the added gaseous fuels and the diluents into the cylinder charge is evaluated using detailed reaction kinetics for the oxidation of dual-fuel mixtures at an adiabatic constant volume process while employing n-heptane as a representative of the main components of the diesel fuel. In the examination of the physical aspects of the delay period, the relative contributions of changes in charge temperature, pressure, physical properties, pre-ignition energy release, heat transfer, and the residual gas effects due to the admission of the gaseous fuels are discussed and evaluated. It is shown that the introduction of gaseous fuels and diluents into the diesel engine can substantially affect both the physical and chemical processes within the ignition delay period. The major extension of the delay is due to the chemical factors, which strongly depend on the type of gaseous fuel used and its concentration in the cylinder charge.

Features of the Piston Engine Working Process when Working on Kerosene

2019 ◽  
pp. 14-20
Author(s):  
Yu.E. Khryashchov ◽  
O.N. Sokolov
Keyword(s):  
Ignition Delay ◽  
Fuel Injection ◽  
Fuel Efficiency ◽  
Delay Period ◽  
Technical Requirement ◽  
Piston Engine ◽  
Working Process ◽  
Factors Affecting ◽  
Exhaust Fumes ◽  
Ignition Delay Period

For aircraft in light multi-purpose aviation, piston engines are considered more efficient than gas turbine. The main technical requirement for such engines is to ensure trouble-free operation with the best possible fuel efficiency. At the same time, there are no requirements to emission of harmful substances in exhaust fumes except for the absence of visible smoke. When developing multi-purpose aircraft piston engines, it is important to ensure their multi-fuel operation, including opera-tion on TS-1 kerosene and diesel fuel. But the issues associated with setting engine control algo-rithms for operation on TS-1 kerosene are practically unexplored. In order to refine the control algo-rithms, the flow of the working process using such fuel was studied in this work. The effect of se-quencing the working process stages on the formation of the ignition delay period was shown. Based on the analysis of the factors affecting the ignition delay period, a map of the fuel injection advance angle values was generated. According to the experimental data, the activation energy of pre-flame reactions was adopted, which for kerosene TS-1 was 23–28 kJ/mol.

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