A Computational Investigation of the Effects of Swirl Ratio and Injection Pressure on Mixture Preparation and Wall Heat Transfer in a Light-Duty Diesel Engine

2013 ◽  
Author(s):  
Federico Perini ◽  
Adam Dempsey ◽  
Rolf D. Reitz ◽  
Dipankar Sahoo ◽  
Benjamin Petersen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Injection Pressure ◽  
Wall Heat Transfer ◽  
Swirl Ratio ◽  
Computational Investigation ◽  
Light Duty ◽  
Mixture Preparation

Effect of Piston Bowl Shape and Swirl Ratio on Engine Heat Transfer in a Light-Duty Diesel Engine

2014 ◽  
Author(s):  
Helgi Skuli Fridriksson ◽  
Martin Tuner ◽  
Oivind Andersson ◽  
Bengt Sunden ◽  
Hakan Persson ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Swirl Ratio ◽  
Piston Bowl ◽  
Light Duty

The Impact of Swirl Ratio and Injection Pressure on Fuel-Air Mixing in a Light-Duty Diesel Engine

2012 ◽  
Author(s):  
Dipankar Sahoo ◽  
Benjamin R. Petersen ◽  
Paul C. Miles
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Mixture Distribution ◽  
Injection Pressure ◽  
Operating Mode ◽  
Swirl Ratio ◽  
Rich Mixture ◽  
Light Duty ◽  
Start Of Injection ◽  
The Impact

Toluene fuel-tracer laser-induced fluorescence is employed to quantitatively measure the equivalence ratio distributions in the cylinder of a light-duty diesel engine operating in a low-temperature, high-EGR, and early-injection operating mode. Measurements are made in a non-combusting environment at crank angles capturing the mixture preparation period: from the start-of-injection through the onset of high-temperature heat release. Three horizontal planes are considered: within the clearance volume, the bowl rim region, and the lower bowl. Swirl ratio and injection pressure are varied independently, and the impact of these parameters on the mixture distribution is correlated to the heat release rate and the engine-out emissions. As the swirl ratio or injection pressure is increased, the amount of over-lean mixture in the upper central region of the combustion chamber, in the bowl rim region and above, also increases. Unexpectedly, increased injection pressure results in a greater quantity of over-rich mixture within the squish volume.

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.

Applying the Representative Interactive Flamelet Model to Evaluate the Potential Effect of Wall Heat Transfer on Soot Emissions in a Small-Bore DI Diesel Engine

2001 ◽  
Author(s):  
Carl Hergart ◽  
Norbert Peters
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Wide Spectrum ◽  
Turbulent Flame ◽  
Combustion Process ◽  
Heat Losses ◽  
Wall Heat Transfer ◽  
Two Phase ◽  
Flamelet Model ◽  
Di Diesel Engine

Abstract Due to the wide spectrum of turbulent and chemical length- and time scales occurring in a HSDI diesel engine, capturing the correct physics and chemistry underlying combustion poses a tremendous modeling challenge. The processes related to the two-phase flow in a DI diesel engine add even more complexity to the total modeling effort. The Representative Interactive Flamelet (RIF) model has gained widespread attention owing to its ability of correctly describing ignition, combustion and pollutant formation phenomena. This is achieved by incorporating very detailed chemistry for the gas phase as well as the soot particle growth and oxidation, without imposing any significant computational penalty. The model, which is based on the laminar flamelet concept, treats a turbulent flame as an ensemble of thin, locally one-dimensional flame structures, whose chemistry is fast. A potential explanation for the significant underprediction of part load soot observed in previous studies applying the model is the neglect of wall heat losses in the flamelet chemistry model. By introducing an additional source term in the flamelet temperature equation, directly coupled to the wall heat transfer predicted by the CFD-code, flamelets exposed to walls are assigned heat losses of various magnitudes. Results using the model in three-dimensional simulations of the combustion process in a small-bore direct injection diesel engine indicate that the experimentally observed emissions of soot may have their origin in flame quenching at the relatively cold combustion chamber walls.

scholarly journals Swirl ratio and post injection strategies to improve late cycle diffusion combustion in a light-duty diesel engine

2017 ◽  
Vol 123 ◽  
pp. 365-376 ◽  
Author(s):  
Jesús Benajes ◽  
Jaime Martín ◽  
Antonio García ◽  
David Villalta ◽  
Alok Warey
Keyword(s):  
Diesel Engine ◽  
Diffusion Combustion ◽  
Post Injection ◽  
Swirl Ratio ◽  
Light Duty ◽  
Injection Strategies

scholarly journals The Differential Impact of Various Injection Pressures on the Exergy of a Diesel Engine Using Biodiesel-Diesel Fuel Blends

2021 ◽  
Vol 14 (1) ◽  
pp. 345
Author(s):  
Mostafa Kiani Deh Kiani ◽  
Sajad Rostami ◽  
Gholamhassan Najafi ◽  
Mohamed Mazlan
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Diesel Fuel ◽  
Exergy Analysis ◽  
Direct Injection ◽  
Injection Pressure ◽  
Cylinder Pressure ◽  
Fuel Blends ◽  
Lack Of Information ◽  
Good Agreement

Contrary to energy, exergy may be destroyed due to irreversibility. Exergy analysis can be used to reveal the location, and amount of energy losses of engines. Despite the importance of the exergy analysis, there is a lack of information in this area, especially when the engine is fueled with biodiesel–diesel fuel blends under various injection operating parameters. Thus, in this research, the exergy analysis of a direct-injection diesel engine using biodiesel–diesel fuel blends was performed. The fuel blends (B0, B20, B40, and B100) were injected into cylinders at pressures of 200 and 215 bars. Moreover, the simulation of exergy and energy analyses was done by homemade code. The simulation model was verified by compression of experimental and simulation in-cylinder pressure data. The results showed there was good agreement between simulation data and experimental ones. Results indicated that the highest level of in-cylinder pressure at injection pressure of 215 bars is more than that of 200 bars. Moreover, by increasing the percentage of biodiesel, the heat transfer exergy, irreversibility, burnt fuel, and exergy indicator decreased, but the ratio of these exergy parameters (except for heat transfer exergy) to fuel exergy increased. These ratios increased from 46 to 50.54% for work transfer exergy, 16.57 to 17.97% for irreversibility, and decreased from 16 to 15.49% for heat transfer exergy. In addition, these ratios at 215 bars are higher than at 200 bars for all fuels. However, with increasing the injection pressure and biodiesel concentration in fuel blends, the exergy and energy efficiencies increased.

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