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.

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.

Characteristics of Premixed Combustion Type Diesel Engine Using Hollow Cone Spray

2001 ◽  
Author(s):  
Tomio Obokata ◽  
Tsuneaki Ishima ◽  
Seiichi Shiga ◽  
Yousuke Eguro ◽  
Tomoyuki Matsuda ◽  
...  
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Maximum Velocity ◽  
Premixed Combustion ◽  
Injection Timing ◽  
Initial Development ◽  
Spray Formation ◽  
Excess Air

Abstract To realize the pre-mixed combustion type Diesel engine, analyses of the wide-angle conical spray flow and its application to the direct injection Diesel engine have been made. In the present work, the spray was evaluated by high speed flow visualization, particle image velocimetry (PTV) measurement, phase Doppler anemometer (PDA) measurement and numerical simulation by KTVA-3V code, and finally the combustion and exhaust characteristics of the proposed engine are examined. The penetration and the shape of the conical sprays under different ambient pressures (0.1, 1.0 and 2.0 MPa) are obtained experimentally and with numerical simulations. Generally, good agreements between them are achieved. It is also cleared that the spray formation is strongly influenced by the surrounding pressure. PIV measurements show the initial development of the spray. The maximum velocity is about 80 m/s, which is almost in the same range as that obtained by the PDA measurements. For the combustion experiment, the excess air ratio was set at 3.1 and 2.5. The engine speed was varied from 1000 to 2000 rpm. Expected premixed combustion region is realized at around the fuel injection timing prior to 65 degree BTDC, where NOx and soot emissions are almost zero at the excess air ratio of 3.1.

scholarly journals A Study on the Effects of Duration of Injection on Emissions and Combustion Characteristics in a Direct Injection Diesel Engine

2014 ◽  
Vol 17 (4) ◽  
pp. 67-76
Author(s):  
Em Van Tong Nguyen ◽  
Khai Le Duy Nguyen
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Injection Timing ◽  
Oxides Of Nitrogen ◽  
Direct Injection Diesel Engine ◽  
Maximum Value ◽  
Nitrogen Emission ◽  
Di Diesel Engine

This paper present a study of the effects of duration of injection on emissions and combustion characteristics in a direct injection diesel engine using CFD code KIVA-3V. In this study, duration of injection was also changed from 6o to 12o CA while the injection timing is constant to evaluate the effect on DI Diesel engine performance, indicated specific fuel consumption and particulates and oxides of nitrogen emission. The obtained results indicate that the capacity of the engine reaches its maximum value and NOx and soot emissions is decreased when the duration of injection is in the range of 6o to 9o CA.

scholarly journals Effects of pilot injection timing and EGR on a modern V6 common rail direct injection diesel engine

2013 ◽  
Vol 50 ◽  
pp. 012008 ◽  
Author(s):  
Nik Rosli Abdullah ◽  
Rizalman Mamat ◽  
Miroslaw L Wyszynski ◽  
Anthanasios Tsolakis ◽  
Hongming Xu
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Common Rail ◽  
Injection Timing ◽  
Pilot Injection ◽  
Direct Injection Diesel Engine

scholarly journals Computer Modelling For 4-Stroke Direct Injection Diesel Engine

2008 ◽  
Vol 33-37 ◽  
pp. 801-806
Author(s):  
Abdul Rahim Ismail ◽  
Rosli Abu Bakar ◽  
Semin Ali ◽  
Ismail Ali
Keyword(s):  
Diesel Engine ◽  
Simulation Study ◽  
Engine Speed ◽  
Computer Modelling ◽  
Direct Injection ◽  
One Dimension ◽  
Effective Pressure ◽  
Operational Parameters ◽  
Direct Injection Diesel Engine ◽  
Theoretical Results

Study on computational modeling of 4-stroke single cylinder direct injection diesel engine is presented. The engine with known specification is being modeled using one dimension CFD GT-Power software. The operational parameters of the engine such as power, torque, specific fuel consumption and mean effective pressure which are dependent to engine speed are being discussed. The results from the simulation study are compared with the theoretical results to get the true trend of the results.

CFD Modelling of the Effects of Injection Timing on the Combustion Process and Emissions in an HSDI Diesel Engine

2012 ◽  
Author(s):  
Raouf Mobasheri ◽  
Zhijun Peng
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection Timing ◽  
Cfd Modelling ◽  
Combustion Modeling ◽  
Pressure Trace ◽  
Hsdi Diesel Engine

High-Speed Direct Injection (HSDI) diesel engines are increasingly used in automotive applications due to superior fuel economy. An advanced CFD simulation has been carried out to analyze the effect of injection timing on combustion process and emission characteristics in a four valves 2.0L Ford diesel engine. The calculation was performed from intake valve closing (IVC) to exhaust valve opening (EVO) at constant speed of 1600 rpm. Since the work was concentrated on the spray injection, mixture formation and combustion process, only a 60° sector mesh was employed for the calculations. For combustion modeling, an improved version of the Coherent Flame Model (ECFM-3Z) has been applied accompanied with advanced models for emission modeling. The results of simulation were compared against experimental data. Good agreement of calculated and measured in-cylinder pressure trace and pollutant formation trends were observed for all investigated operating points. In addition, the results showed that the current CFD model can be applied as a beneficial tool for analyzing the parameters of the diesel combustion under HSDI operating condition.

scholarly journals Experimental study of multiple pilot injection strategy in an automotive direct injection diesel engine

2018 ◽  
Vol 234 ◽  
pp. 03007
Author(s):  
Plamen Punov ◽  
Tsvetomir Gechev ◽  
Svetoslav Mihalkov ◽  
Pierre Podevin ◽  
Dalibor Barta
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Diesel Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection Timing ◽  
Pilot Injection ◽  
Injection Strategy ◽  
Direct Injection Diesel Engine ◽  
Rate Of Heat Release

The pilot injection strategy is a widely used approach for reducing the noise of the combustion process in direct injection diesel engines. In the last generation of automotive diesel engines up to several pilot injections could occur to better control the rate of heat release (ROHR) in the cylinder as well as the pollutant formation. However, determination of the timing and duration for each pilot injection needs to be precisely optimised. In this paper an experimental study of the pilot injection strategy was conducted on a direct injection diesel engine. Single and double pilot injection strategy was studied. The engine rated power is 100 kW at 4000 rpm while the rated torque is 320 Nm at 2000 rpm. An engine operating point determined by the rotation speed of 1400 rpm and torque of 100 Nm was chosen. The pilot and pre-injection timing was widely varied in order to study the influence on the combustion process as well as on the fuel consumption.

Sign in / Sign up

Export Citation Format

Share Document