The Research on Multi-dimensional Numerical Analog Computation of Diesel Spray and Combustion Process

2010 ◽  
Author(s):  
Wen-ming Cheng ◽  
Gang Li ◽  
Jie Peng
Keyword(s):  
Combustion Process ◽  
Diesel Spray ◽  
Analog Computation

Combustion Process of Diesel Spray in High Temperature Air

1995 ◽  
Author(s):  
Yiming Wang ◽  
Guocai Shu ◽  
Changlin Yang ◽  
Yincheng Ju ◽  
Kuihan Zhao
Keyword(s):  
High Temperature ◽  
Combustion Process ◽  
Diesel Spray

scholarly journals CHARACTERIZATION OF DIESEL SPRAY IMAGES USING A SHAPE PROCESSING METHODOLOGY

2011 ◽  
Vol 24 (2) ◽  
pp. 95 ◽  
Author(s):  
Cecile Petit ◽  
Wolfgang Reckers ◽  
Jean-Marie Becker ◽  
Michel Jourlin
Keyword(s):  
Combustion Process ◽  
Diesel Spray ◽  
Spray Structure ◽  
Shape Coding ◽  
Spray Plume ◽  
Shape Processing ◽  
Air Mixing ◽  
Efficient Combustion ◽  
And Behavior

In Diesel engines, a key element in achieving a clean and efficient combustion process is a proper fuel-air mixing, which is a consequence of the fuel spray development and fuel-air interaction inside the engine combustion chamber. The spray structure and behavior are classically described by the length (penetration) and width (angle) of the spray plume but these parameters do not give any clue on the geometrical injection center and on the spray symmetry. The purpose of this paper is to find out original tools to characterize the Diesel spray: the virtual spray origin is the geometrical injection center, which may (or may not) coincide with the injector axis. Another interesting point is the description of the Diesel spray in terms of symmetry: the spray plume internal and external symmetry characterize the spray and the injector performance. Our approach is first to find out the virtual spray origin: after the image segmentation, the spray is coded with the Freeman code and with an original shape coding from which the moments are derived. The symmetry axes are then computed and the spray plumes are discarded (or not) for the virtual spray origin computation, which is derived from a Voronoi diagram. The last step is the internal and external spray plume symmetry characterization thanks to correlation and mathematical distances.

scholarly journals Phenomenological modeling of diesel spray with varying injection profile

2018 ◽  
Vol 233 (11) ◽  
pp. 2780-2790 ◽  
Author(s):  
Long Liu ◽  
Yan Peng ◽  
Xiuzhen Ma ◽  
Naoto Horibe ◽  
Takuji Ishiyama
Keyword(s):  
Mass Flow Rate ◽  
Flow Rate ◽  
Momentum Flux ◽  
Combustion Process ◽  
Injection Rate ◽  
Diesel Spray ◽  
Sectional Area ◽  
Cross Sectional ◽  
Spray Penetration ◽  
Fuel Mass

Accurate and quick prediction of spray characteristics such as spray penetration is paramount for the understanding and quantitative analysis of the combustion process in diesel engines, in order to perform parametric study on advanced combustion process in diesel engines, zero-dimensional diesel spray model is often used for the prediction of the spray evolution. In this study, a previous zero-dimensional diesel spray model applied for the spray penetration prediction including the part after the end of injection with a constant injection rate was extended to the cases with varying injection rate. The effective injection velocity was introduced into the previous spray model, which is defined as the ratio of the momentum flux and fuel mass flow rate over the spray tip cross-sectional area. Combined with this definition, the analysis of effective injection rate and its response time was performed during and after the end of injection. After that, the fuel mass flow rate and momentum flux over the spray tip cross-sectional area were derived for varying injection rate even after the end of injection based on the momentum and fuel mass conservation along the spray axis, and further the spray penetration. Finally, the developed model was validated by comparing with the experimental data.

Large Eddy Simulation of Diesel Spray Combustion With a Multi-Component Drop Vaporization Model

2017 ◽  
Author(s):  
Xiaohua Ren ◽  
Lei Zhang ◽  
Zhongli Ji
Keyword(s):  
Experimental Data ◽  
Large Eddy Simulation ◽  
Combustion Process ◽  
Dynamic Structure ◽  
Diesel Spray ◽  
Grid Turbulence ◽  
Fuel Droplets ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Les Model

Large-eddy simulation (LES) of diesel spray and combustion was performed to study its improvement in the simulation of engine in-cylinder dynamics compared to the Reynolds-averaged simulation. For the LES, the dynamic structure approach was used to model the sub-grid turbulence and its interaction with the moving droplets in the spray. A multicomponent vaporization model (MCV) based on the continuous thermodynamics approach and a gamma distribution to describe the distribution of the numerous fuel components, was used to simulate the vaporization of diesel fuel droplets. The MCV model was imbedded into the LES framework in the KIVA-4 program. Using this LES model, a non-evaporative spray in a constant-volume chamber was first simulated. More realistic spray structures and improved agreements in the spray penetration with the experimental data were obtained by the LES compared to a Reynolds-averaged simulation of the same spray. A further simulation of an evaporative diesel spray and the subsequent combustion process using both LES and MCV models was also performed. Improved agreements with the experimental data in the spray structures and soot distributions were also observed using both models.

Effect of Jet-Jet Angle on Combustion Process of Diesel Spray in an RCEM

2020 ◽  
Author(s):  
Hyun Jo ◽  
Taichi Ishikawa ◽  
Naoto Horibe ◽  
Jun Hayashi ◽  
Hiroshi Kawanabe ◽  
...  
Keyword(s):  
Combustion Process ◽  
Diesel Spray

Effects of split ratio of diesel spray injection on mixture formation and combustion process

2021 ◽  
pp. 095440702110143
Author(s):  
Samir Chandra Ray ◽  
Jaeheun Kim ◽  
Scinichi Kakami ◽  
Keiya Nishida ◽  
Yoichi Ogata
Keyword(s):  
High Speed ◽  
Dwell Time ◽  
Equivalence Ratio ◽  
Soot Formation ◽  
Combustion Process ◽  
Air Entrainment ◽  
Diesel Spray ◽  
Injection Timing ◽  
Mixture Formation ◽  
Split Ratio

The effects of the split ratio on the mixture formation and combustion process of a diesel spray in a constant-volume chamber were experimentally investigated. A commercial seven-hole injector was used in this experiment. The effects of the mass-dependent split ratio and dwell time were observed when the total fuel injection was 5.0 mg/hole. Three split ratios were considered: 3:7, 5:5 and 7:3, while the dwell time of 120 µs was fixed for every condition. A laser absorption-scattering technique was adopted to examine the formation of mixtures with regarding to the equivalence ratio. A high-speed video camera was used to observe natural flame luminosity, and a two-colour pyrometer system was employed to evaluate the temperature and soot concentrations in the flame. Among the distribution ratios tested in this study, the 7:3 split ratio exhibited the best performance for the lean mixture formation considering the overall equivalence ratio distribution. The air entrainment wave at the end of injection timing of the first injection caused the fuel near the nozzle to lean at a rapid rate. The soot formation process for the 3:7 and 5:5 split ratios was observed because the second injection fuel caught the flame of the previous injections; this deteriorated the combustion region and influenced soot formation. The result also revealed that for the 7:3 split ratio, accelerated the soot deduction rate to the cycle of soot oxidation during the combustion period.

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