Modeling of Spray Wall Impingement and Fuel Film Formation under the Gasoline Direct Injection Condition

2022 ◽  
Author(s):  
junghyun kim ◽  
Jongwon Chung ◽  
Jaeyup Lee ◽  
Sunyoung Moon ◽  
Kyoungdoug Min
Keyword(s):  
Film Formation ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Fuel Film ◽  
Injection Condition ◽  
Wall Impingement

scholarly journals Impingement characteristics of an early injection gasoline direct injection engine: A numerical study

2016 ◽  
Vol 18 (4) ◽  
pp. 378-393 ◽  
Author(s):  
Nicholas J Beavis ◽  
Salah S Ibrahim ◽  
Weeratunge Malalasekera
Keyword(s):  
Liquid Film ◽  
Film Formation ◽  
Direct Injection ◽  
Cylinder Liner ◽  
Gasoline Direct Injection ◽  
Intake Valve ◽  
Direct Injection Engine ◽  
Gasoline Direct Injection Engine ◽  
Start Of Injection ◽  
Early Injection

This article describes the use of a Lagrangian discrete droplet model to evaluate the liquid fuel impingement characteristics on the internal surfaces of an early injection gasoline direct injection engine. This study focuses on fuel impingement on the intake valve and cylinder liner between start of injection and 20° after start of injection using both a single- and a multi-component fuels. The single-component fuel used was iso-octane and the multi-component fuel contained fractions of iso-pentane, iso-octane and n-decane to represent the light, medium and heavy fuel fractions of gasoline, respectively. A detailed description of the impingement and liquid film modelling approach is also provided. Fuel properties, wall surface temperature and droplet Weber number and Laplace number were used to quantify the impingement regime for different fuel fractions and correlated well with the predicted onset of liquid film formation. Evidence of film stripping was seen from the liquid film formed on the side of the intake valve head with subsequent ejected droplets being a likely source of unburned hydrocarbons and particulate matter emissions. Differences in impingement location and subsequent location of liquid film formation were also observed between single- and multi-component fuels. A qualitative comparison with experimental cylinder liner impingement data showed the model to well predict the timing and positioning of the liner fuel impingement.

Effect of ultra-high injection pressure up to 50 MPa on macroscopic spray characteristics of a multi-hole gasoline direct injection injector fueled with ethanol

2017 ◽  
Vol 232 (8) ◽  
pp. 1092-1104 ◽  
Author(s):  
Xiang Li ◽  
Yi-qiang Pei ◽  
Jing Qin ◽  
Dan Zhang ◽  
Kun Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Direct Injection ◽  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Mixture ◽  
Gasoline Direct Injection ◽  
Spray Characteristics ◽  
High Injection ◽  
High Injection Pressure ◽  
Wall Impingement

This research systematically studied the effect of injection pressure on macroscopic spray characteristics of a five-hole gasoline direct injection (GDI) injector fueled with ethanol, especially under ultra-high injection pressure up to 50 MPa. The front and side views of sprays were photographed by the schlieren method using a high-speed camera. Various parameters, including spray development stages, cone angle, penetration, area and irregular ratio, were fully analyzed to evaluate macroscopic characteristics of the whole spray and spray core with varying injection pressure. The results demonstrated that the effect of ultra-high injection pressure on macroscopic spray characteristics was significant. As injection pressure increased from 10 MPa to 50 MPa, the occurrence time of branch-like structure decreased; the cone angle increased little; the area increased significantly; the area ratio dropped by 6.4 and 5.8 percentage points on average for the front view and side view spray, respectively. There was a significant increase in the trend for penetration as the injection pressure rose from 10 MPa to 30 MPa. However, this trend became weak when the injection pressure further increased. The penetration ratio under ultra-high injection pressure was slightly higher than it was under 10 or 20 MPa. Ultra-high injection pressure would not obviously raise the possibility of spray/wall impingement, but led to the impingement quantity increasing to some extent. Increasing injection pressure could enhance the vortex scale, finally resulting in better air/fuel mixing quality. Ultra-high injection pressure was a potential way to improve air/fuel mixture homogeneity for a GDI injector fueled with ethanol.

scholarly journals Modeling the effect of spray/wall impingement on combustion process and emission of DI diesel engine

2009 ◽  
Vol 13 (3) ◽  
pp. 23-33 ◽  
Author(s):  
Samad Jafarmadar ◽  
Shram Khalilarya ◽  
Sina Shafee ◽  
Ramin Barzegar
Keyword(s):  
Diesel Engine ◽  
Film Formation ◽  
Direct Injection ◽  
Combustion Process ◽  
Three Dimensional ◽  
Three Dimensional Modeling ◽  
Wall Film ◽  
Wall Impingement ◽  
Di Diesel Engine ◽  
Fuel Mixing

This work is presented to study the effect of spray impinging on the combustion process and emissions in a direct injection diesel engine at various engine speeds. Computations are carried out using a three-dimensional modeling for sprays, spray-wall interactions, flow field, emission, and combustion process. Results indicate an increase in engine speed leads to increased spray impinging (wall film formation), turbulence intensity and average wall temperature in cylinder. The enhanced air/fuel mixing and intensified evaporation of wall film decreases soot emission by reducing the extent of the fuel rich regions specially in impinging zones. Also at higher engine speeds, combustion is delayed and fuel is consumed in a shorter time period by the enhanced air and fuel mixing. The shorter combustion duration provides less available time for soot and NOx formations. However, only a few attempts have been made to address the effect of impingement of spray with piston walls on the emissions and combustion process. The results of model in addition to approving the corresponding data in the literature are also compared with the experimental data and shown good agreement.

Experimental Investigations on Fuel Spray and Impingement for Gasoline Direct Injection Engines

2021 ◽  
Author(s):  
Hongliang Luo
Keyword(s):  
Cooling System ◽  
Direct Injection ◽  
Fuel Spray ◽  
Fuel Film ◽  
Direct Injection Engines ◽  
Index Matching ◽  
Wall Impingement ◽  
Refractive Index Matching ◽  
Temperature Constant ◽  
And Performance

Spray-wall impingement is a widespread phenomenon applied in many fields, including spray-wall cooling system, spray coating process and fuel spray and atomization in internal combustion engines. In direct-injection spark ignition (DISI), it is difficult to avoid the fuel film on the piston head and cylinder surfaces. The wet wall caused by impingement affects the air-fuel mixture formation process, which finally influence the subsequent combustion efficiency and performance. Therefore, the fuel spray and impingement under gasoline engine-like conditions were characterized. Mie scattering technique was applied to visualize the spray evolution and impingement processes in a high-pressure and high-temperature constant chamber. Meanwhile, the adhered fuel film on the wall was measured by refractive index matching (RIM) under non-evaporation and evaporation conditions considering the effects of different injection pressures, ambient pressures and ambient temperatures. Additionally, the fuel film formation and evaporation evolution models were proposed with the help of these mechanisms.

A numerical–experimental assessment of wall impingement models for spark-ignition direct-injection engines

2019 ◽  
Vol 21 (2) ◽  
pp. 281-301
Author(s):  
Ronald O Grover ◽  
Todd D Fansler ◽  
Andreas Lippert ◽  
Michael C Drake ◽  
Dennis N Assanis
Keyword(s):  
Light Transmission ◽  
Film Formation ◽  
Direct Injection ◽  
Spark Ignition ◽  
Mie Scattering ◽  
Quantitative Agreement ◽  
Atmospheric Conditions ◽  
Direct Injection Engines ◽  
Wall Impingement ◽  
Film Area

Liquid wall impingement in direct-injection engines can cause soot and hydrocarbon emissions as well as reduced combustion efficiency. This study focuses on detailed evaluations of numerical droplet impingement criteria that govern the onset of splash. The five selected splash criteria, which all extrapolate from single-droplet impacts to full sprays, are representative of those currently in use for spark-ignition direct-injection engines. The computations examined the sensitivity of impinging spray simulations to the splash criteria for a high-pressure, direct-injection swirl spray under atmospheric conditions impinging at a 45° angle onto a flat plate. The numerical results were compared to an unusually extensive set of experimental data: Mie scattering and light transmission imaging, plus quantitative refractive index matching measurements of the fuel film area and thickness, and phase Doppler interferometry measurements of droplet size and velocity near the plate. Good qualitative and at least fair quantitative agreement was obtained for the global spray impingement and wall film formation, especially for single-drop criteria that include the effect of viscosity. The film area and shape were insensitive to the splash criteria, illustrating the importance of film thickness measurements for validating simulations. The results also revealed the sensitivity of impingement calculations to droplet arrival frequency when that is taken into account. In general, the comparisons indicated the need to capture the effect of multiple droplets impinging on the wall at irregular frequencies in the criterion, as well as other important physics of the droplet–wall interaction that may mask the true effect of the impingement criterion.

SANDVIK PRESSURFECT

Alloy Digest ◽  
2015 ◽  
Vol 64 (1) ◽  
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Direct Injection ◽  
Heat Treating ◽  
Gasoline Direct Injection ◽  
Fuel System ◽  
Bend Strength ◽  
Low Carbon ◽  
Steel Company

Abstract Sandvik Pressurfect is an austenitic chromium-nickel stainless steel with low carbon content used for high-pressure gasoline direct injection (GDI) fuel system. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as heat treating and machining. Filing Code: SS-1195. Producer or source: Sandvik Steel Company.

Comparative study on combustion and thermodynamics performance of gasoline direct injection (GDI) engine under cold start and warm-up NEDC

2019 ◽  
Vol 181 ◽  
pp. 663-673 ◽  
Author(s):  
Qi Liu ◽  
Jingping Liu ◽  
Jianqin Fu ◽  
Yangyang Li ◽  
Baojun Luo ◽  
...  
Keyword(s):  
Comparative Study ◽  
Direct Injection ◽  
Cold Start ◽  
Gasoline Direct Injection ◽  
Warm Up ◽  
Gdi Engine
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