Effect of High Swirl Velocity on Mixture Formation and Combustion Process of Diesel Spray

2012 ◽  
Vol 229-231 ◽  
pp. 695-699 ◽  
Author(s):  
Amir Khalid ◽  
Bukhari Manshoor
Keyword(s):  
Combustion Chamber ◽  
High Speed ◽  
Combustion Process ◽  
Video Camera ◽  
Exhaust Emissions ◽  
Ignition Process ◽  
Mixture Formation ◽  
Digital Video Camera ◽  
Swirl Velocity ◽  
Flame Development

Diesel engines generate undesirable exhaust emissions during combustion process and identified as major source pollution in the worldwide ecosystem. To reduce emissions, the improvements throughout the premixing of fuel and air have been considered especially at early stage of ignition process. Purpose of this study is to clarify the effects of swirl velocity on flow fuel-air premixing mechanism and burning process in diesel combustion that strongly affects the exhaust emissions. The effects of physical factors on mixture formation and combustion process to improve exhaust emissions are discussed in detail. This study investigated diesel combustion fundamentally using a rapid compression machine (RCM) together with the schlieren photography and direct photography methods. RCM was used to simulate actual phenomenon inside the combustion chamber with changing design parameter such as swirl velocity, injection strategies and variable nozzle concept. The detail behavior of mixture formation during ignition delay period was investigated using the schlieren photography system with a high speed digital video camera. This method can capture spray evaporation, spray interference and mixture formation clearly with real images. Ignition process and flame development were investigated by direct photography method using a light sensitive high-speed color digital video camera. Moreover, the mechanism and behavior of mixture formation were analyzed by newly developed image analysis technique. Under high swirl condition, the ignition delay is extended, the higher heat losses and unutilized high-density oxygen associated with slower initial heat recovery begins might be the explanation for the longer combustion duration, reductions of pick heat release and promote combustion and soot oxidation. The real images of mixture formation and flame development reveal that the spray tip penetration is bended by the high swirl motion, fuel is mainly distributed at the center of combustion chamber, resulting that flame is only formed at the center region of the combustion chamber. It is necessary for high swirl condition to improve fuel-air premixing.

Effect of Pilot Injection on Mixture Formation, Ignition Process and Flame Development in Diesel Combustion

2013 ◽  
Vol 390 ◽  
pp. 327-332 ◽  
Author(s):  
Amir Khalid ◽  
M. Jaat ◽  
Izzuddin Zaman ◽  
B. Manshoor ◽  
Mas Fawzi
Keyword(s):  
Ignition Delay ◽  
High Speed ◽  
Combustion Process ◽  
Video Camera ◽  
Delay Period ◽  
Ignition Process ◽  
Pilot Injection ◽  
Mixture Formation ◽  
Digital Video Camera ◽  
Ignition Delay Period

The alternative combustion strategies with systematic control of mixture formation have provided new opportunities and considerable improvement in the combustion process and response to meet the stringent emissions standards. Purpose of this research is to investigate the influences of pilot injection on the fuel-air premixing especially during ignition delay period. During this period, the interaction between fuel spray and surrounding gas prior to ignition which linked to the improvement of mixture formation, ignition process and initial heat recovery thus predominantly influences the combustion process and exhaust emissions. This study investigates the effects of pilot injection using a rapid compression machine together with the schlieren photography and direct photography methods. The detail behavior of mixture formation during ignition delay period was investigated using the schlieren photography system with a high speed digital video camera. This method can capture spray evaporation, spray interference and mixture formation clearly with real images. Ignition process and flame development were investigated by direct photography method using a light sensitive high-speed color digital video camera. Pilot injection promotes mixture formation during ignition delay period and slower oxidation reaction and thus leads to earlier rise and lower peak heat release rate.

Experimental Investigation of Mixture Formation and Flame Development Using the Basics Technique of Schlieren Optical Visualization Principle

2014 ◽  
Vol 660 ◽  
pp. 474-478
Author(s):  
Dahrum Samsudin ◽  
Safwan Othman ◽  
M.D. Anuar ◽  
Bukhari Manshoor ◽  
Amir Khalid
Keyword(s):  
Low Cost ◽  
Combustion Process ◽  
Video Camera ◽  
Combustible Mixture ◽  
Biodiesel Fuel ◽  
Mixture Formation ◽  
Digital Video Camera ◽  
Optical Visualization ◽  
Flame Development ◽  
Air Mixing

The Schlieren technique remains to be one of the most powerful technique to visualize the flow and it is relatively easy to implement, high and variable sensitivity, low cost and its used conventional of light. This technique allows us to see the invisible of the optical inhomogeneities in transparent media like air, water and glass that otherwise cause only ghostly distortions of our normal vision. This research investigates the mixture formation and flame development of biodiesel fuel using the Schlieren optical visualization principle. This method can capture spray evaporation, spray interference, mixture formation and flame pattern clearly with real images. During the experiment, the camera lens was used with telephoto lenses (Nikon 70-300mm f/4-5.6G) in order to capture a large amount of light especially the low flame intensity during the initial flame development. The flame development was captured with color images from a color digital video camera. This method can capture the flow of fluids of varying density, such as spray evaporation, spray interference and mixture formation clearly with real images. The result shows that the mechanism of fuel-air mixing and a better comprehension of combustible mixture that can give valuable information to improve and optimize the combustion process.

High Speed Combustion Imaging in a Large Bore Gas Engine: The Relationship Between Pre- and Main Chamber Heat Release

2013 ◽  
Author(s):  
Jeudi Duong ◽  
Rikard Wellander ◽  
Jari Hyvönen ◽  
Öivind Andersson ◽  
Mattias Richter ◽  
...  
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Flame Propagation ◽  
High Speed ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Video Camera ◽  
Main Chamber ◽  
Lean Burn ◽  
Combustion Heat

An experimental study is carried out to investigate the combustion process in a Wärtsilä 34SG spark-ignited lean burn four-stroke large bore engine (bore 340 mm) by means of optical diagnostics when operating on natural gas. The main focus of this work is to gain knowledge about in-cylinder combustion phenomena when igniting a lean air/fuel mixture with pre-combustion chamber induced jets. Especially the origin of cyclic variability is of interest. The flame propagation process in a single cycle was captured using a high speed video camera. The analysis is based on apparent heat release rates in the pre-combustion chamber and main chamber, in order to find correlations with the imaged phenomena. The results show that the flame propagation inside the main chamber starts at the end of the pre-chamber combustion heat release and that variation in main chamber heat release does not correlate with variations in the pre-combustion chamber.

Analysis of the Variable Cross-Section Duct and Straightening Device Geometry Effects on the Hydrogen Combustion Process

2021 ◽  
pp. 62-71
Author(s):  
O.V. Guskov ◽  
V.S. Zakharov ◽  
Minko
Keyword(s):  
Combustion Chamber ◽  
Cross Section ◽  
High Speed ◽  
Power Plants ◽  
Combustion Process ◽  
Variable Cross Section ◽  
Hydrogen Combustion ◽  
Variable Cross ◽  
Calculation Methods ◽  
Transition Channel

The development and research of high-speed aircrafts and their individual parts is an urgent scientific task. In the scientific literature there is information about the integral characteristics of aircrafts of this type, but there is no detailed consideration of such an important part as the transition channel between the air intake and the combustion chamber. The article considers several flow path configurations. The numerical simulation results of hydrogen combustion in the channels of variable cross section using a detailed kinetic mechanism are presented. Based on the analysis of the data obtained, the models of the transition channel and the combustion chamber showing the best characteristics were selected. The impulse and the fuel combustion efficiency are used as criteria for comparing the flow paths. The difference in the application of two calculation methods is described. The presented results and calculation methods can be used at the stage of computational research of the working processes in advanced power plants.

Review of the Investigation of Fuel-Air Premixing and Combustion Process Using Rapid Compression Machine and Direct Visualization System

2013 ◽  
Vol 465-466 ◽  
pp. 265-269 ◽  
Author(s):  
Mohamad Jaat ◽  
Amir Khalid ◽  
Bukhari Manshoor ◽  
Siti Mariam Basharie ◽  
Him Ramsy
Keyword(s):  
High Speed ◽  
Combustion Engine ◽  
Early Stage ◽  
Combustion Process ◽  
Injection Pressure ◽  
Rapid Compression Machine ◽  
Mixture Formation ◽  
Visualization System ◽  
Optical Visualization ◽  
Rapid Compression

s :This paper reviews of some applications of optical visualization system to compute the fuel-air mixing process during early stage of mixture formation and late injection in Diesel Combustion Engine. This review has shown that the mixture formation is controlled by the characteristics of the injection systems, the nature of the air swirl and turbulence in thecylinder, and spray characteristics. Few experimental works have been investigated and found that the effects of injection pressure and swirl ratio have a great effect on the mixture formation then affects to the flame development and combustion characteristics.This paper presents the significance of spray and combustion study with optical techniques access rapid compression machine that have been reported by previous researchers. Experimental results are presentedin order to provide in depth knowledge as assistance to readers interested in this research area. Analysis of flame motion and flame intensity in the combustion chamber was performed using high speed direct photographs and image analysis technique. The application of these methods to the investigation of diesel sprays highlights mechanisms which provide a better understanding of spray and combustion characteristics.

Analysis of Mixture Formation and Flame Development of Diesel Combustion Using a Rapid Compression Machine and Optical Visualization Technique

2013 ◽  
Vol 315 ◽  
pp. 293-298 ◽  
Author(s):  
Amir Khalid ◽  
Bukhari Manshoor
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Exhaust Emissions ◽  
Combustion Characteristics ◽  
Diesel Combustion ◽  
Rapid Compression Machine ◽  
Mixture Formation ◽  
Optical Visualization ◽  
Flame Development ◽  
Rapid Compression

Mixture formation plays as a key element on burning process that strongly affects the exhaust emissions such as nitrogen oxide (NOx) and Particulate Matter (PM). The reductions of emissions can be achieved with improvement throughout the mixing of fuel and air behavior. Measurements were made in an optically-accessible rapid compression machine (RCM) with intended to simulate the actual diesel combustion related phenomena. The diesel combustion was simulated with the RCM which is equipped with the Denso single-shot common-rail fuel injection system, capable of a maximum injection pressure up to 160MPa. Diesel engine compression process could be reproduced within the wide range of ambient temperature, ambient density, swirl velocity, equivalence ratio and fuel injection pressure. The mixture formation and combustion images were captured by the high speed camera. Analysis of combustion characteristics and observations of optical visualization of images reveal that the mixture formation exhibit influences to the ignition process and flame development. Therefore, the examination of the first stage of mixture formation is very important consideration due to the fuel-air premixing process linked with the combustion characteristics. Furthermore, the observation of a systematic control of mixture formation with experimental apparatus enables us to achieve considerable improvements of combustion process and would present the information for fundamental understanding in terms of reduced fuel consumption and exhaust emissions.

scholarly journals Analysis of creation and combustion process of hydrogen-air mixtures by optical method in isochoric chamber

2017 ◽  
Vol 170 (3) ◽  
pp. 121-125
Author(s):  
Marek BRZEŻAŃSKI ◽  
Tadeusz PAPUGA ◽  
Łukasz RODAK
Keyword(s):  
Combustion Chamber ◽  
Flame Front ◽  
Dose Distribution ◽  
Optical Method ◽  
Direct Injection ◽  
Combustion Process ◽  
Variable Composition ◽  
Mixture Formation ◽  
Before And After

The article considers the analysis of combustion process of hydrogen-air mixture of variable composition. Direct injection of hydrogen into the isochoric combustion chamber was applied and the mixture formation took place during the combustion process. The influence of the dose distribution of the fuel supplied before and after ignition on the formation of the flame front and the course of the pressure in the isochoric combustion chamber was discussed. The filming process and registration of pressure in the isochoric chamber during research of combustion process was applied.

Observation on Solid Propellant Ignition Using High Speed Camera: The Effect of Hot Wire Position on the Combustion Flame Contour

2014 ◽  
Vol 71 (2) ◽  
Author(s):  
Wan Khairuddin Wan Ali ◽  
Ang Kiang Long ◽  
Mohammad Nazri Mohd. Jaafar
Keyword(s):  
Solid Propellant ◽  
High Speed ◽  
Flame Structure ◽  
Combustion Process ◽  
Ignition Process ◽  
High Speed Camera ◽  
Hot Wire ◽  
Composite Propellant ◽  
Burning Behavior ◽  
Insight Into

This paper reports on the discovery of unique flame structure of a composite propellant sample under hot wire ignition. The entire combustion process at atmospheric pressure condition was recorded using a high speed camera. Three hot wire orientations were chosen in this experiment for examining their effects on the propellant burning behavior. The results show that the wire orientations are crucial in propellant combustion process, as different flame patterns were observed when the hot wire orientation was altered. This paper provides an important insight into this specific ignition process that can be useful for researchers in the aerospace industry for better design and more realistic simulation results in ignition control.

scholarly journals Experimental Studies of Fuel Injection in a Diesel Engine with an Inclined Injector

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2643
Author(s):  
V. G. Kamaltdinov ◽  
V. A. Markov ◽  
I. O. Lysov ◽  
A. A. Zherdev ◽  
V. V. Furman
Keyword(s):  
Combustion Chamber ◽  
High Speed ◽  
Cone Angle ◽  
Combustion Process ◽  
Experimental Studies ◽  
Uneven Distribution ◽  
Orifice Diameter ◽  
Spray Cone ◽  
Fuel Sprays ◽  
The Difference

Comparative experimental studies of fuel sprays evolution dynamics in a constant volume chamber were carried out with a view to reduce the uneven distribution of diesel fuel in the combustion chamber when the Common Rail injector is inclined. The fuel sprays was captured by a high-speed camera with simultaneous recording of control pulses of camera and injector on an oscilloscope. Two eight-hole diesel injectors were investigated: One injector with identical orifice diameter (nozzle 1) and another injector with four orifices of the same diameter as orifices of nozzle 1 and four orifices of enlarged diameters (nozzle 2). Both injectors were tested at rail pressure from 100 to 165 MPa and injector control pulse width of 1.5 ms. The dynamics of changes in the spray penetration length and spray cone angle were determined. It was found that sprays develop differently in nozzle 1 fuel. The difference in the length of fuel sprays is 10–15 mm. As for nozzle 2, the fuel sprays develop more evenly: The difference in length is no more than 3–5 mm. The difference of the measured fuel spray cone angles for nozzle 1 is 0.5°–1.5°, and for nozzle 2 is 3.0°–4.0°. It is concluded that the differential increase in the diameters of nozzle orifices, the axes of which are maximally deviated from the injector axis, makes it possible to reduce the uneven distribution of fuel in the combustion chamber and improve the combustion process and the diesel performance as a whole.

Visualization of diesel spray and combustion from lateral side of two-dimensional piston cavity in rapid compression and expansion machine

2020 ◽  
pp. 146808742096229
Author(s):  
Chengyuan Fan ◽  
Daoyuan Wang ◽  
Keiya Nishida ◽  
Yoichi Ogata
Keyword(s):  
High Speed ◽  
Combustion Process ◽  
Video Camera ◽  
Lateral Side ◽  
Two Dimensional ◽  
Split Injection ◽  
Compression And Expansion ◽  
Color Video ◽  
Wall Interaction ◽  
Injection Strategies

Effect of spray/wall interaction in a rapid compression and expansion machine on mixture formation, ignition location, and soot generation was investigated. A two-dimensional piston cavity designed as the cross section of a reentrant piston was utilized to observe the spray and combustion process from the lateral side. The experiment was conducted at 120 MPa injection pressure under single and split injection strategies with an ambient gas of 15% O2 concentration. A shadow methodology was applied to investigate the interaction between the fuel spray and the piston cavity. Combined with the natural flame luminosity captured by a high-speed color video camera, the behaviors of the impinging spray and the combustion process were studied. The combustion characteristics of the in-cylinder pressure, heat release and combustion phase were recorded and analyzed simultaneously. The results showed that the split injection strategies effectively softened the heat release trace and promoted the onset of the main combustion. The cool-flame phenomenon was captured by using the high-speed color video camera, and the intense ignition was observed when the pilot spray was controlled to impinge on the lower lip of the piston rim. Moreover, results also showed that further extending the mixing process of the pilot spray is inclined to form a homogeneous mixture which was beneficial for the promotion of low-temperature combustion and the reduction of soot generation. This research provides a detailed investigation on the spray and combustion process and it highlights the significant effect of spray/wall interaction on the subsequent combustion process.

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