Modeling the Effects of EGR and Injection Pressure on Emissions in a High-Speed Direct-Injection Diesel Engine

2001 ◽  
Author(s):  
K. J. Richards ◽  
M. N. Subramaniam ◽  
Rolf D. Reitz ◽  
Ming-Chia Lai ◽  
N. A. Henein ◽  
...  
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Direct Injection ◽  
Injection Pressure ◽  
Direct Injection Diesel Engine

Effect of Swirl Ratio and Injection Pressure on Autoignition, Combustion and Emissions in a High Speed Direct Injection Diesel Engine Fuelled With Biodiesel (B-20)

2009 ◽  
Author(s):  
Vinay Nagaraju ◽  
Mufaddel Dahodwala ◽  
Kaushik Acharya ◽  
Walter Bryzik ◽  
Naeim A. Henein
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Direct Injection ◽  
Injection Pressure ◽  
Combustible Mixture ◽  
Injection System ◽  
Ignition Process ◽  
Swirl Ratio ◽  
Mixture Formation ◽  
Physical And Chemical

Biodiesel has different physical and chemical properties than ultra low sulfur diesel fuel (ULSD). The low volatility of biodiesel is expected to affect the physical processes, mainly fuel evaporation and combustible mixture formation. The higher cetane number of biodiesel is expected to affect the rates of the chemical reactions. The combination of these two fuel properties has an impact on the auto ignition process, subsequently combustion and engine out emissions. Applying different swirl ratios and injection pressures affect both the physical and chemical processes. The focus of this paper is to investigate the effect of varying the swirl ratio and injection pressure in a single-cylinder research diesel engine using a blend of biodiesel and ULSD fuel. The engine is a High Speed Direct Injection (HSDI) equipped with a common rail injection system, EGR system and a swirl control mechanism. The engine is operated under simulated turbocharged conditions with 3 bar Indicated Mean Effective Pressure (IMEP) at 1500 rpm, using 100% ULSD and a blend of 20% biodiesel and 80% ULSD fuel. The biodiesel is developed from soy bean oil. A detailed analysis of the apparent rate of heat release (ARHR) is made to determine the role of the biodiesel component of B-20 in the combustible mixture formation, autoignition process, premixed, mixing controlled and diffusion controlled combustion fractions. The results explain the factors that cause an increase or a drop in NOx emissions reported in the literature when using biodiesel.

On the Premixed Combustion in a Direct-Injection Diesel Engine

1987 ◽  
Vol 109 (2) ◽  
pp. 187-192 ◽  
Author(s):  
A. C. Alkidas
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Engine Speed ◽  
Direct Injection ◽  
Premixed Combustion ◽  
Injection Timing ◽  
Oxides Of Nitrogen ◽  
Nitrogen Emissions ◽  
Direct Injection Diesel Engine ◽  
Diffusion Burning

The factors influencing premixed burning and the importance of premixed burning on the exhaust emissions from a small high-speed direct-injection diesel engine were investigated. The characteristics of premixed and diffusion burning were examined using a single-zone heat-release analysis. The mass of fuel burned in premixed combustion was found to be linearly related to the product of engine speed and ignition-delay time and to be essentially independent of the total amount of fuel injected. Accordingly, the premixed-burned fraction increased with increasing engine speed, with decreasing fuel-air ratio and with retarding injection timing. The hydrocarbon emissions did not correlate well with the premixed-burned fraction. In contrast, the oxides of nitrogen emissions were found to increase with decreasing premixed-burned fraction, indicating that diffusion burning, and not premixed burning, is the primary source of oxides of nitrogen emissions.

Characteristics of performance and emissions in high-speed direct injection diesel engine fueled with diethyl ether/diesel fuel blends

Energy ◽  
2012 ◽  
Vol 43 (1) ◽  
pp. 214-224 ◽  
Author(s):  
Dimitrios C. Rakopoulos ◽  
Constantine D. Rakopoulos ◽  
Evangelos G. Giakoumis ◽  
Athanasios M. Dimaratos
Keyword(s):  
Diesel Engine ◽  
Diethyl Ether ◽  
Diesel Fuel ◽  
High Speed ◽  
Direct Injection ◽  
Direct Injection Diesel Engine ◽  
Fuel Blends ◽  
Performance And Emissions

Low-sooting combustion in a small-bore high-speed direct-injection diesel engine using narrow-angle injectors

2008 ◽  
Vol 222 (10) ◽  
pp. 1927-1937 ◽  
Author(s):  
T-G Fang ◽  
R E Coverdill ◽  
C-F F Lee ◽  
R A White
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Operating Conditions ◽  
Injection Timing ◽  
Exhaust Pipe ◽  
Injection Angle ◽  
Direct Injection Diesel Engine ◽  
Combustion Flame

An optically accessible high-speed direct-injection diesel engine was used to study the effects of injection angles on low-sooting combustion. A digital high-speed camera was employed to capture the entire cycle combustion and spray evolution processes under seven operating conditions including post-top-dead centre (TDC) injection and pre-TDC injection strategies. The nitrogen oxide (NO x) emissions were also measured in the exhaust pipe. In-cylinder pressure data and heat release rate calculations were conducted. All the cases show premixed combustion features. For post-TDC injection cases, a large amount of fuel deposition is seen for a narrower-injection-angle tip, i.e. the 70° tip, and ignition is observed near the injector tip in the centre of the bowl, while for a wider-injection-angle tip, namely a 110° tip, ignition occurs near the spray tip in the vicinity of the bowl wall. The combustion flame is near the bowl wall and at the central region of the bowl for the 70° tip. However, the flame is more distributed and centralized for the 110° tip. Longer spray penetration is found for the pre-TDC injection timing cases. Liquid fuel impinges on the bowl wall or on the piston top and a fuel film is formed. Ignition for all the pre-TDC injection cases occur in a distributed way in the piston bowl. Two different combustion modes are observed for the pre-TDC injection cases including a homogeneous bulky combustion flame at earlier crank angles and a heterogeneous film combustion mode with luminous sooting flame at later crank angles. In terms of soot emissions, NO x emissions, and fuel efficiency, results show that the late post-TDC injection strategy gives the best performance.

Effect of Injection Parameters and Strategy on the Noise From a Single Cylinder Direct Injection Diesel Engine

2011 ◽  
Author(s):  
Sukhbir Singh Khaira ◽  
Amandeep Singh ◽  
Marcis Jansons
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Injection Pressure ◽  
Combustion Noise ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Frequency Spectra ◽  
Single Cylinder ◽  
Direct Injection Diesel Engine ◽  
Injection Parameters

Acoustic noise emitted by a diesel engine generally exceeds that produced by its spark-ignited equivalent and may hinder the acceptance of this more efficient engine type in the passenger car market (1). This work characterizes the combustion noise from a single-cylinder direct-injection diesel engine and examines the degree to which it may be minimized by optimal choice of injection parameters. The relative contribution of motoring, combustion and resonance components to overall engine noise are determined by decomposition of in-cylinder pressure traces over a range of load, injection pressure and start of injection. The frequency spectra of microphone signals recorded external to the engine are correlated with those of in-cylinder pressure traces. Short Time Fourier Transformation (STFT) is applied to cylinder pressure traces to reveal the occurrence of motoring, combustion noise and resonance in the frequency domain over the course of the engine cycle. Loudness is found to increase with enhanced resonance, in proportion to the rate of cylinder pressure rise and under conditions of high injection pressure, load and advanced injection timing.

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