The Interaction Between the Pilot Diesel and Main NG Injection in an HPDI Engine

2021 ◽  
Author(s):  
N. Diepstraten ◽  
X. L. J. Seykens ◽  
L. M. T. Somers
Keyword(s):  
Initial Temperature ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Low Carbon ◽  
Reactor Model ◽  
Local Conditions ◽  
Diesel Injection ◽  
Homogeneous Reactor ◽  
Small Change ◽  
Combat Climate Change

Abstract High Pressure Direct Injection (HPDI) is a promising combustion concept for the medium- to heavy-duty industry to combat climate change. It uses a pilot diesel injection to ignite the main fuel consisting of Natural Gas (NG). Both fuels are injected directly in the combustion chamber using a dedicated HPDI injector. A significant reduction in carbon dioxide and Particulate Matter is achieved due to the use of the low carbon fuel NG. It is seen in literature that a small change in pilot injection can have profound consequences for the HPDI combustion. This research investigates the interaction between the pilot diesel and main NG injection. A relevant Computational Fluid Dynamics (CFD) simulation environment is setup for this purpose. It is observed that the main NG injection needs a certain pilot trigger to ignite. Furthermore, local conditions are derived to investigate driving factors of the ignition of NG on a fundamental level. A homogeneous reactor model is used to study Ignition Delay (ID) behavior by varying the initial temperature as well as concentrations of radicals H and OH. It is observed that both factors influence the ID. The initial temperature has to be higher than 1110 K in order to ignite the NG under enginelike conditions. It is also observed that species mole fractions H or OH encountered in the CFD simulation can reduce the ID up to 5.5 crank angle degrees at a speed of 1400 RPM.

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.

scholarly journals Complex Valuation of Energy from Agricultural Crops including Local Conditions

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1415
Author(s):  
Václav Voltr ◽  
Martin Hruška ◽  
Luboš Nobilis
Keyword(s):  
Soil Quality ◽  
Environmental Impacts ◽  
Climatic Conditions ◽  
Energy Crops ◽  
Co2 Production ◽  
Low Carbon ◽  
Local Conditions ◽  
Low Carbon Economy ◽  
Silage Maize ◽  
Marginal Areas

This paper provides values of economic, energy and environmental assessments of 20 crops and assesses the relationships of soil-climatic conditions in the example of the Czech Republic. The comparison of main soil quality indicators according to the configuration of land and climate regions is performed on the basis of energy and economic efficiency as well as a comparison of the level of environmental impacts. The environmental impacts are identified based on the assessment of emissions from production and also in the form of soil compaction as an indicator of the relationship to soil quality. As concerns soil properties, of major importance is soil skeleton, slope of land and the depth of soil, which cause an increase in emissions from the energy produced. Substantially better emission parameters per 1 MJ through energy crops, the cultivation of perennial crops and silage maize has been supported. Among energy crops, a positive relationship with the quality of soil is seen in alfalfa, with a significant reduction in soil penetrometric resistance; energy crops are also politically justifiable in competition with other crops intended for nutrition of population. The main advantage of energy crops for the low-carbon economy is their CO2 production to MJ, which is almost half, especially in marginal areas with lower soil depths, slopes and stoniness, which can be included in the new agricultural policy.

CFD Modelling of the Effects of Injection Timing on the Combustion Process and Emissions in an HSDI Diesel Engine

2012 ◽  
Author(s):  
Raouf Mobasheri ◽  
Zhijun Peng
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection Timing ◽  
Cfd Modelling ◽  
Combustion Modeling ◽  
Pressure Trace ◽  
Hsdi Diesel Engine

High-Speed Direct Injection (HSDI) diesel engines are increasingly used in automotive applications due to superior fuel economy. An advanced CFD simulation has been carried out to analyze the effect of injection timing on combustion process and emission characteristics in a four valves 2.0L Ford diesel engine. The calculation was performed from intake valve closing (IVC) to exhaust valve opening (EVO) at constant speed of 1600 rpm. Since the work was concentrated on the spray injection, mixture formation and combustion process, only a 60° sector mesh was employed for the calculations. For combustion modeling, an improved version of the Coherent Flame Model (ECFM-3Z) has been applied accompanied with advanced models for emission modeling. The results of simulation were compared against experimental data. Good agreement of calculated and measured in-cylinder pressure trace and pollutant formation trends were observed for all investigated operating points. In addition, the results showed that the current CFD model can be applied as a beneficial tool for analyzing the parameters of the diesel combustion under HSDI operating condition.

Combining Instantaneous Temperature Measurements and CFD for Analysis of Fuel Impingement on the DISI Engine Piston Top

2009 ◽  
Author(s):  
Kukwon Cho ◽  
Ronald O. Grover ◽  
Dennis Assanis ◽  
Zoran Filipi ◽  
Gerald Szekely ◽  
...  
Keyword(s):  
Film Thickness ◽  
Heat Loss ◽  
Cfd Simulation ◽  
Computational Study ◽  
Fluid Dynamic ◽  
Direct Injection ◽  
Negative Temperature ◽  
Fuel Injector ◽  
Fuel Film ◽  
Film Evaporation

A two-pronged experimental and computational study was conducted to explore the formation, transport, and vaporization of a wall film located on the piston surface within a four-valve, pent roof, direct-injection spark-ignition (DISI) engine, with the fuel injector located between the two intake valves. Negative temperature swings were observed at three piston locations during early injection, thus confirming the ability of fast-response thermocouples to capture the effects of impingement and heat loss associated with fuel film evaporation. Computational Fluid Dynamic (CFD) simulation results demonstrated that the fuel film evaporation process is extremely fast under conditions present during intake. Hence, the heat loss measured on the surface can be directly tied to the heating of the fuel film and its complete evaporation, with the wetted area estimated based on CFD predictions. This finding is critical for estimating the local fuel film thickness from measured heat loss. The simulated fuel film thickness and transport corroborated well temporally and spatially with measurements at thermocouple locations directly in the path of the spray, thus validating the spray and impingement models. Under the strategies tested, up to 23% of fuel injected impinges upon the piston and creates a fuel film with thickness of up to 1.2 μm. In summary, the study demonstrates the usefulness of heat flux measurements to quantitatively characterize the fuel film on the piston top and allows for validation of the CFD code.

CFD Simulation and Wind Tunnel Investigation of a FPSO Offshore Helideck Turbulent Flow

2010 ◽  
Author(s):  
Daniel Fonseca de Carvalho e Silva ◽  
Paulo Roberto Pagot ◽  
Gilder Nader ◽  
Paulo Jose´ Saiz Jabardo
Keyword(s):  
Wind Tunnel ◽  
Particle Image ◽  
Cfd Simulation ◽  
Wind Flow ◽  
Cfd Simulations ◽  
Local Conditions ◽  
British Standard ◽  
Ansys Cfx ◽  
Tunnel Model ◽  
Image Velocimetry

The offshore helideck wind flow is usually subject to many interferences. The helideck airspace velocity and turbulence fields are important issues to promote safe helicopter take-off and landing operations. The current work brings some CFD results of a helideck wind flow 3D-field defined by the local conditions and constrained by the FPSO structure. A discussion about the chosen CFD boundary conditions is also presented. These CFD results are compared with the wind tunnel model-scale velocity and turbulence measurements. The wind tunnel measurements were performed with use of two different techniques: Particle Image Velocimetry (PIV) and Constant Temperature Anemometry (CTA). The British standard CAP437: Offshore Helideck Design Criteria is examined and suggestions are made herein. The CFD simulations were conducted using the ANSYS CFX software.

Combining Instantaneous Temperature Measurements and CFD for Analysis of Fuel Impingement on the DISI Engine Piston Top

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Kukwon Cho ◽  
Ronald O. Grover ◽  
Dennis Assanis ◽  
Zoran Filipi ◽  
Gerald Szekely ◽  
...  
Keyword(s):  
Film Thickness ◽  
Heat Loss ◽  
Cfd Simulation ◽  
Computational Study ◽  
Direct Injection ◽  
Negative Temperature ◽  
Spark Ignition Engine ◽  
Fuel Injector ◽  
Fuel Film ◽  
Film Evaporation

A two-pronged experimental and computational study was conducted to explore the formation, transport, and vaporization of a wall film located at the piston surface within a four-valve, pent-roof, direct-injection spark-ignition engine, with the fuel injector located between the two intake valves. Negative temperature swings were observed at three piston locations during early injection, thus confirming the ability of fast-response thermocouples to capture the effects of impingement and heat loss associated with fuel film evaporation. Computational fluid dynamics (CFD) simulation results indicated that the fuel film evaporation process is extremely fast under conditions present during intake. Hence, the heat loss measured on the surface can be directly tied to the heating of the fuel film and its complete evaporation, with the wetted area estimated based on CFD predictions. This finding is critical for estimating the local fuel film thickness from measured heat loss. The simulated fuel film thickness and transport corroborated well temporally and spatially with measurements at thermocouple locations directly in the path of the spray, thus validating the spray and impingement models. Under the strategies tested, up to 23% of fuel injected impinges upon the piston and creates a fuel film with thickness of up to 1.2 μm. In summary, the study demonstrates the usefulness of heat flux measurements to quantitatively characterize the fuel film on the piston top and allows for validation of the CFD code.

scholarly journals Effect of Injection Pressures on Emissions of Direct Injection Diesel Engine By Using CFD Simulation

2016 ◽  
Vol 13 (05) ◽  
pp. 15-19
Author(s):  
C. Anuradha ◽  
T. Anand Kumar ◽  
Dr. M .Lakshmi Kantha Reddy ◽  
Dr.G. Prasanthi
Keyword(s):  
Diesel Engine ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Direct Injection Diesel Engine ◽  
Injection Pressures

scholarly journals Impact of the Primary Break-Up Strategy on the Morphology of GDI Sprays in 3D-CFD Simulations of Multi-Hole Injectors

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2890 ◽  
Author(s):  
Sparacino ◽  
Berni ◽  
d’Adamo ◽  
Krastev ◽  
Cavicchi ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Direct Injection ◽  
Flow Simulation ◽  
Back Pressure ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Ambient Conditions ◽  
Phase Doppler Anemometry ◽  
Break Up ◽  
Primary Break

The scientific literature focusing on the numerical simulation of fuel sprays is rich in atomization and secondary break-up models. However, it is well known that the predictive capability of even the most diffused models is affected by the combination of injection parameters and operating conditions, especially backpressure. In this paper, an alternative atomization strategy is proposed for the 3D-Computational Fluid Dynamics (CFD) simulation of Gasoline Direct Injection (GDI) sprays, aiming at extending simulation predictive capabilities over a wider range of operating conditions. In particular, attention is focused on the effects of back pressure, which has a remarkable impact on both the morphology and the sizing of GDI sprays. 3D-CFD Lagrangian simulations of two different multi-hole injectors are presented. The first injector is a 5-hole GDI prototype unit operated at ambient conditions. The second one is the well-known Spray G, characterized by a higher back pressure (up to 0.6 MPa). Numerical results are compared against experiments in terms of liquid penetration and Phase Doppler Anemometry (PDA) data of droplet sizing/velocity and imaging. CFD results are demonstrated to be highly sensitive to spray vessel pressure, mainly because of the atomization strategy. The proposed alternative approach proves to strongly reduce such dependency. Moreover, in order to further validate the alternative primary break-up strategy adopted for the initialization of the droplets, an internal nozzle flow simulation is carried out on the Spray G injector, able to provide information on the characteristic diameter of the liquid column exiting from the nozzle.

scholarly journals 2D CFD Simulation of Water Injection Strategies in a Large Marine Engine

2019 ◽  
Vol 7 (9) ◽  
pp. 296 ◽  
Author(s):  
Senčić ◽  
Mrzljak ◽  
Blecich ◽  
Bonefačić
Keyword(s):  
Cfd Simulation ◽  
Soot Formation ◽  
Direct Injection ◽  
Water Injection ◽  
Engine Performance ◽  
Nox Emissions ◽  
Water Emulsion ◽  
Marine Engine ◽  
Soot Emissions ◽  
Injection Strategies

A two-dimensional computational fluid dynamics (2D CFD) simulation of a low-speed two-stroke marine engine simulation was performed in order to investigate the performance of 2D meshes that allow the use of more complex chemical schemes and pollutant formation analysis. Various mesh density simulations were compared with a 3D mesh simulation and with the experimentally obtained cylinder pressure. A heavy fuel model and a soot model were implemented in the software. Finally, the influences of three water injection strategies were simulated and evaluated in order to investigate the capability of the model and the influence of water injection on NOx formation, soot formation, and engine performance. We conclude that the direct water injection strategy reduces NOx emissions without adversely affecting the engine performance or soot emissions. The other two strategies—Intake air humidification and direct injection of fuel–water emulsion—reduced NOx emissions but at the cost of higher soot emissions or reduced engine performance.

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