Effect of Combustion Chamber Geometry on Emissions From a Single-Cylinder Diesel Engine

2005 ◽  
Author(s):  
Boggavarapu V. V. S. U. Prasad ◽  
R. V. Ravikrishna
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Direct Injection ◽  
Three Dimensional ◽  
Cfd Simulations ◽  
Government Regulations ◽  
Single Cylinder ◽  
Piston Bowl ◽  
Computational Fluid Dynamics Cfd ◽  
Valve Part

Many of the stationary power generation and agricultural pumping applications in India utilize diesel engines. Recently, as per Government regulations, these engines are required to satisfy stringent emissions norms. This forms the motivation for the present study on a stationary, direct-injection, single cylinder, 10 HP diesel engine. The selected engine was not satisfying the norms. The engine has a hemi- spherical piston bowl and an injector with a finite sac volume. The combustion chamber was made re-entrant and the injector was replaced with a sac-less injector. After these modifications, there is a significant change in emission levels. To understand clearly the effect of the combustion chamber geometry on the emission levels, three-dimensional computational fluid dynamics (CFD) simulations have been performed for the complete suction and closed-valve part of the cycle. Comparisons of turbulent kinetic energy and swirl levels of old and new geometries were systematically conducted. In contrary to the expected, that the swirl and turbulence levels are consistently less in the modified geometry than that of original geometry. A third combustion chamber was proposed and tested computationally. It was found that the in the proposed combustion chamber swirl and turbulence levels are much higher than the baseline engine. Thus, the proposed combustion chamber geometry shows significant potential for the engine to meet the prescribed norms.

scholarly journals Influence of combustion chamber geometry on performance and emissions of diesel engine Vikyno RV125-2

2015 ◽  
Vol 18 (1) ◽  
pp. 102-111
Author(s):  
Khai Le Duy Nguyen ◽  
Hung Dac Khanh Nguyen
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Compression Ratio ◽  
Direct Injection ◽  
Soot Concentration ◽  
Research Results ◽  
Direct Injection Diesel Engine ◽  
Piston Bowl ◽  
Performance And Emissions ◽  
Engine Power

This paper presents a research on the influence of combustion chamber geometry on performance and emissions of direct injection diesel engine VIKYNO RV125-2 using threedimensional CFD code KIVA-3V. In this study, the piston bowl depth (pip-height), bottom bowl diameter and bowl diameter are changed while the engine compression ratio is still kept. Research results indicate that increased bowl diameter works best. Specifically, when the bowl diameter changes from 3.98cm to 4.7cm, the engine power is increased 22.6%, while the concentration of NOx is reduced 0.85%. However soot concentration will increase 45.83%.

scholarly journals Combined effects of combustion chamber geometry and injection strategy on combustion and emissions of a diesel engine

2021 ◽  
Vol 268 ◽  
pp. 01026
Author(s):  
Jizhou Zhang ◽  
Fuwu Yan ◽  
Yu Wang
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Fuel Injection ◽  
Direct Injection ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Complete Combustion ◽  
Injection Strategy ◽  
Injection Duration ◽  
Chamber Volume

For a certain type of direct injection diesel engine, a three-dimensional model of a single-cylinder complete combustion chamber and in-take/exhaust port was established. Three-dimensional Computational Fluid Dynamics (CFD) analysis software CONVERGE was used for simulation. The effects of fuel injection strategy and combustion chamber geometry on combustion emissions of diesel engine were studied while the combustion chamber volume, engine compression ratio, total fuel injection quantity and total injection duration were kept unchanged. The results show that the strategy of multiple injection and reasonable shape of combustion chamber can effectively increase the turbulent kinetic energy in cylinder, improve the uniformity of oil-gas mixing, reduce the emission of pollutants, and increase the quality of after injection can further reduce the emissions of NOx and soot.

IN-CYLINDER FLOW ANALYSIS FOR A DIRECT INJECTION DIESEL ENGINE – A CFD APPROACH

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Ananthakumar S ◽  
Jayabal S ◽  
Thirumal P
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Diesel Engine ◽  
Combustion Chamber ◽  
Direct Injection ◽  
Flow Analysis ◽  
Direct Injection Diesel Engine ◽  
Piston Bowl ◽  
Mexican Hat ◽  
Swirl Velocity

A parametric study of the effect of piston bowl configuration on air motion of a direct injection diesel engine motored at 3000 rpm is investigated. Two piston bowl configurations (Mexican-hat and Re-entrant) are modeled for the computational flow analysis. The flow characteristics of these engine bowls are examined under transient conditions using STAR CD, a commercial computational fluid dynamics package. The predicted computational fluid dynamics results of mean swirl velocity of the engine at different locations inside the combustion chamber, at the end of compression stroke were compared with experimental results available in the literature. The results obtained showed very good agreement with the measured data given in the literature. This paper discusses the predicted flow structure inside the combustion chamber at top dead center, with different piston bowl shapes at 3000 rpm. It also compares the radial distribution of mean swirl velocity component in the piston bowl for the two cases. It is observed that the Re-entrant bowl provides a higher swirl ratio at almost all locations than the Mexican hat bowl.

Analysis of the Injection Process in Direct Injected Natural Gas Engines: Part II—Effects of Injector and Combustion Chamber Design

1994 ◽  
Vol 116 (4) ◽  
pp. 806-813 ◽  
Author(s):  
M. J. Jennings ◽  
F. R. Jeske
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Negative Impact ◽  
Direct Injection ◽  
Three Dimensional ◽  
Optimal Number ◽  
Design Parameters ◽  
Piston Bowl ◽  
Injection Process ◽  
Computational Fluid Dynamics Analysis

A study of natural gas (NG) direct injection (DI) processes in engines has been performed using multidimensional computational fluid dynamics analysis. The purpose was to investigate the effects of key engine design parameters on the mixing in DI NG engines. Full three-dimensional calculations of injection into a medium heavy-duty diesel engine cylinder were performed. Perturbations on a baseline engine configuration were considered. In spite of single plume axisymmetric injection calculations that show mixing improves as nozzle hole size is reduced: plume merging caused by having too many nozzle holes has a severe negative impact on mixing; and increasing the number of injector holes strengthens plume deflection toward the cylinder head, which also adversely affects mixing. The optimal number of holes for a quiescent engine was found to be that which produces the largest number of separate NG plumes. Increasing the nozzle angle to reduce plume deflection can adversely affect mixing due to reduced jet radial penetration. Increasing the injector tip height is an effective approach to eliminating plume deflection and improving mixing. Extremely high-velocity squish flows, with penetration to the center of the piston bowl, are necessary to have a significant impact on mixing. Possible improvements in mixing can be realized by relieving the center of the piston bowl in typical “Mexican hat” bowl designs. CFD analysis can effectively be used to optimize combustion chamber geometry by fitting the geometry to computed plume shapes.

Effect of Combustion Chamber Design on the Performance and Emission Characteristics of a Direct Injection (DI) Diesel Engine Fuelled With Refined Rice Bran Oil Blends

2004 ◽  
Author(s):  
A. Samuel Raja ◽  
G. Lakshmi Narayana Rao ◽  
N. Nallusamy ◽  
M. Selva Ganesh Kumar
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Direct Injection ◽  
Spherical Shape ◽  
Experimental Investigations ◽  
Emission Characteristics ◽  
Performance And Emission ◽  
Piston Bowl

The present work deals with the experimental investigations on the effect of refined rice bran oil and its blends with diesel on performance and emission characteristics of diesel engine with different combustion chamber geometry. The engine was tested with various neat vegetable oils and it was found that with refined rice bran oil the performance and emission characteristics were comparable with that of neat diesel. The K- factor of the combustion chamber geometry (ratio of the piston bowl volume to the clearance volume) was maintained at 0.74. The D/d ratio (ratio of piston crown diameter to piston bowl diameter) was altered to achieve re-entrant and torroidal shapes from spherical shape. Tests were carried out for each blend, with particular geometry of combustion chamber. Results with different combustion chamber geometry and different blends have been compared.

Effect of Multiple Injections on Fuel-Air Mixing and Soot Formation in Diesel Combustion Using Direct Flame Visualization and CFD Techniques

2005 ◽  
Author(s):  
Christos A. Chryssakis ◽  
Dennis N. Assanis ◽  
Sanghoon Kook ◽  
Choongsik Bae
Keyword(s):  
Fuel Injection ◽  
Soot Formation ◽  
Direct Injection ◽  
Injection System ◽  
Diesel Combustion ◽  
Cfd Simulations ◽  
Single Cylinder ◽  
Multiple Injections ◽  
Air Mixing ◽  
Computational Fluid Dynamics Cfd

The main objective of this study is to investigate the effect of pilot-, post- and multiple-fuel injection strategies on fuel-air mixing and emissions formation in diesel combustion, using a combination of experimental observations and Computational Fluid Dynamics (CFD) analysis. The experimental study was carried out on a single-cylinder optical direct-injection diesel engine equipped with a high pressure common rail fuel injection system. The experimental work was supported by CFD simulations on the single-cylinder engine in order to investigate the effect of multiple injections on mixture formation. The limitations of the soot formation model were identified through direct comparisons with experimental flame visualization.

Numerical and Experimental Investigation of Thermo–Acoustic Combustion Instability in a Longitudinal Combustion Chamber: Influence of the Geometry of the Plenum

2015 ◽  
Author(s):  
Davide Laera ◽  
Andrea Gentile ◽  
Sergio M. Camporeale ◽  
Edoardo Bertolotto ◽  
Luca Rofi ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Energy Production ◽  
Three Dimensional ◽  
Acoustic Energy ◽  
Energy Losses ◽  
Combustion Instabilities ◽  
Cfd Simulations ◽  
Pressure Oscillations ◽  
Dimensional Distribution ◽  
Computational Fluid Dynamics Cfd

This paper concerns the study of self–sustained combustion instabilities that occur in a test rig characterized by a single longitudinal combustion chamber equipped with a full scale industrial burner and a longitudinal plenum. The length of both plenum and combustion chamber can be continuously varied. During tests, at a fixed value of the length of the combustion chamber, a sensibility of the amplitude of pressure oscillations to the length of the plenum has been registered, while the frequency remained constant. To investigate this behavior, a linear stability analysis has been performed evaluating the influence of the length of the plenum on the frequency and growth rate of the registered unstable mode. The analysis has been performed by means of a finite element method (FEM) code with a three–dimensional distribution of the n-τ Flame Transfer Function (FTF) computed by means of computational fluid dynamics (CFD) simulations. According to the Rayleigh criterion, the distribution of the local Rayleigh index has been computed in order to evaluate the acoustic energy production, while the scattering matrix of the entire system has been used to evaluate the acoustic energy losses. Numerical results show that the reduction of the plenum length induces an increase of acoustic energy losses while the energy production remains almost constant. This result is in agreement with the reduction of the pressure oscillations amplitude observed during tests.

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