Three-Dimensional Simulation of Gaseous Fuel Injection Through a Hybrid Approach

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
L. Andreassi ◽  
A. L. Facci ◽  
S. Ubertini
Keyword(s):  
Fuel Injection ◽  
Combustion Engine ◽  
Direct Injection ◽  
Hybrid Approach ◽  
Three Dimensional ◽  
Air Entrainment ◽  
Gaseous Fuel ◽  
Injection System ◽  
Injection Process ◽  
Dimensional Simulation

Direct injection of gaseous fuel has emerged to be a high potential strategy to tackle both environmental and fuel economy requirements. However, since the electronic gaseous injection technology is rather new for automotive applications, limited experience exists on the optimum configuration of the injection system and the combustion chamber. To facilitate the development of these applications computer models are being developed to simulate gaseous injection, air entrainment, and the ensuing combustion. This paper introduces a new method for modeling the injection process of gaseous fuels in multidimensional simulations. The proposed model allows holding down grid requirements, thus, making it compatible with the three-dimensional simulation of an internal combustion engine.

A Multidimensional Model to Simulate Direct Gaseous Fuel Injection in Internal Combustion Engines

2009 ◽  
Author(s):  
L. Andreassi ◽  
A. L. Facci ◽  
S. Ubertini
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Combustion Process ◽  
Three Dimensional ◽  
Air Entrainment ◽  
Internal Combustion ◽  
Numerical Results ◽  
Gaseous Fuel ◽  
Injection System

As a consequence of the endless price growing of oil, and oil derivate fuels, automotive industry is experiencing a concerning decreasing in sales. Accordingly, in order to meet customer needs, there is every day a greater interest in solutions for increasing engine efficiency. On the other hand the growing attention to environmental problems leads to increasingly restrictive regulations, such as European EURO 4 and EURO 5. Direct injection of gaseous fuel has emerged to be a high potential strategy to tackle both environmental and fuel economy requirements. However since the electronic gaseous injection technology is rather new for automotive applications, limited experience exists on the optimum configuration of the injection system and the combustion chamber. To facilitate the development of these applications computer models are being developed to simulate gaseous injection, air entrainment and the ensuing combustion. This paper introduces a new method for modelling the injection process of gaseous fuels in multi-dimensional simulations. The proposed model allows holding down grid requirements, thus making it compatible with the three-dimensional simulation of an internal combustion engine. The model is validated and calibrated by comparing numerical results with available experimental data. To highlight the potential applications, some numerical results of the three-dimensional combustion process in a gas engine are presented.

Inline Pump Internal Flow Characterization for Optimized Diesel Injection

2008 ◽  
Author(s):  
G. Chiatti ◽  
O. Chiavola ◽  
F. Palmieri
Keyword(s):  
Formation Control ◽  
Fuel Injection ◽  
Three Dimensional ◽  
Internal Flow ◽  
Injection Rate ◽  
Local Pressure ◽  
Injection Process ◽  
Flow Characterization ◽  
Dimensional Simulation ◽  
And Performance

The injection process optimization plays a key role in diesel engine development activities, both for pollutant formation control and performance improvement. The present paper focuses on relatively small diesel units, equipped with fully mechanical injection systems; in detail, the considered system layout is based on the use of spring injectors; the amount of delivered fuel is controlled by the positioning of the pump plunger groove. The paper highlights the role of the inline pump and the influence of fuel characteristics on the system operation. By means of a three-dimensional numerical flow study, the behavior of pump fuel passages and delivery valve is simulated. Then, on the basis of the system features, a complete lumped/one-dimensional numerical model is realized, in which the discharge coefficients evaluated through the three-dimensional simulation are employed. Fuel injection rate and local pressure time histories are investigated, paying specific attention to the occurrence of the relevant phenomena in the system components. Obtained results are compared with experimental data.

CFD and Optical Investigations of Fluid Dynamics and Mixture Formation in a DI-H2ICE

2010 ◽  
Author(s):  
Riccardo Scarcelli ◽  
Thomas Wallner ◽  
Hermann Obermair ◽  
Victor M. Salazar ◽  
Sebastian A. Kaiser
Keyword(s):  
Mole Fraction ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Direct Injection ◽  
Three Dimensional ◽  
Symmetry Plane ◽  
Injection Velocity ◽  
Compression Stroke ◽  
Commercial Code ◽  
Wall Interaction

This paper reports the validation of a three-dimensional numerical simulation of the in-cylinder processes during gas-exchange, injection, and compression in a direct-injection, hydrogen-fueled internal combustion engine. Computational results from the commercial code Fluent are compared to experimental data acquired by laser-based measurements in a corresponding optically accessible engine. The simulation includes the intake-port geometry as well as the injection event with its supersonic hydrogen jet. The cylinder geometry is typical of passenger-car sized spark-ignited engines. Gaseous hydrogen is injected from a high-pressure injector with a single-hole nozzle. Numerically and experimentally determined flow fields in the vertical, central symmetry plane are compared for a series of crank angles during the compression stroke, with and without fuel injection. With hydrogen injection, the fuel mole-fraction in the same data plane is included in the comparison as well. The results show that the simulation predicts the flow field without injection reasonably well, with increasing numerical-experimental disagreement towards the end of the compression stroke. The injection event completely disrupts the intake-induced flow, and the simulation predicts the post-injection velocity fields much better than the flow without injection at the same crank-angles. The two-dimensional tumble ratio is evaluated to quantify the coherent barrel motion of the charge. Without fuel injection, the simulation significantly over-predicts tumble during most of the compression stroke, but with injection, the numerical and experimental tumble ratio track each other closely. The evolution of hydrogen mole-fraction during the compression stroke shows conflicting trends. Jet penetration and jet-wall interaction are well captured, while fuel dispersion appears under-predicted. Possible causes of this latter discrepancy are discussed.

A Phenomenological Model for Combustion and Emissions in Small Bore, High Speed, Direct Injection Diesel Engines

2005 ◽  
Author(s):  
N. A. Henein ◽  
I. P. Singh ◽  
L. Zhong ◽  
Y. Poonawala ◽  
J. Singh ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Phenomenological Model ◽  
High Speed ◽  
Gas Flow ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Injection Process ◽  
Wide Range

This paper introduces a phenomenological model for the fuel distribution, combustion, and emissions formation in the small bore, high speed direct injection diesel engine. A differentiation is made between the conditions in large bore and small bore diesel engines, particularly regarding the fuel impingement on the walls and the swirl and squish gas flow components. The model considers the fuel injected prior to the development of the flame, fuel injected in the flame, fuel deposited on the walls and the last part of the fuel delivered at the end of the injection process. The model is based on experimental results obtained in a single-cylinder, 4-valve, direct-injection, four-stroke-cycle, water-cooled, diesel engine equipped with a common rail fuel injection system. The engine is supercharged with heated shop air, and the exhaust back pressure is adjusted to simulate actual turbo-charged diesel engine conditions. The experiments covered a wide range of injection pressures, EGR rates, injection timings and swirl ratios. Correlations and 2-D maps are developed to show the effect of combinations of the above parameters on engine out emissions. Emphasis is made on the nitric oxide and soot measured in Bosch Smoke Units (BSU).

scholarly journals Modelling and simulation of working processes in Wankel engine with direct hydrogen injection system

2015 ◽  
Vol 161 (2) ◽  
pp. 42-52
Author(s):  
Władysław MITIANIEC
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Compression Process ◽  
Injection Process ◽  
High Pollution ◽  
Spatial System ◽  
Scavenge Process ◽  
Wankel Engine ◽  
Inertia Forces

Wankel engines were very attractive in automotive sector almost forty years ago because of small dimensions, compactness, simple design, smoothness of engine work and lack of vibration caused by inertia forces. The disadvantage of such engine was very high pollution, especially of hydrocarbons and carbon monoxide and high fuel consumption. These disadvantages can be eliminated by applying of direct injection of hydrogen and in the aviation sector by applying of fuel with high octane number also at a direct injection system. The main objective of the work is modelling of the thermodynamic process taking place during the scavenge process in such engine. At assumed geometry of the engine, initial and boundary conditions the change of engine parameters such as pressure, temperature, density, heat exchange and volume are calculated on the base of zero-dimensional model as a function of rotation angle of the piston. Forming of the mixture during fuel injection process in compression process gives information about the air excess ratio. The presented model is applicable for different sort of fuels. This work is introduction to a broader analysis of the processes in spatial system. Application of hydrogen reduces of toxic components emission from such engine, but decreases also engine power.

Effect of Piston Crevices on the Numerical Simulation of a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark-Ignition Operation

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Iolanda Stocchi ◽  
Jinlong Liu ◽  
Cosmin Emil Dumitrescu ◽  
Michele Battistoni ◽  
Carlo Nazareno Grimaldi
Keyword(s):  
Heat Release ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Direct Injection ◽  
Three Dimensional ◽  
Spark Ignition ◽  
Combustion Model ◽  
Heavy Duty ◽  
Compression Ignition Engine ◽  
Heavy Duty Diesel

Three-dimensional computational fluid dynamics internal combustion engine simulations that use a simplified combustion model based on the flamelet concept provide acceptable results with minimum computational costs and reasonable running times. Moreover, the simulation can neglect small combustion chamber details such as valve crevices, valve recesses, and piston crevices volume. The missing volumes are usually compensated by changes in the squish volume (i.e., by increasing the clearance height of the model compared to the real engine). This paper documents some of the effects that such an approach would have on the simulated results of the combustion phenomena inside a conventional heavy-duty direct injection compression-ignition engine, which was converted to port fuel injection spark ignition operation. Numerical engine simulations with or without crevice volumes were run using the G-equation combustion model. A proper parameter choice ensured that the numerical results agreed well with the experimental pressure trace and the heat release rate. The results show that including the crevice volume affected the mass of a unburned mixture inside the squish region, which in turn influenced the flame behavior and heat release during late-combustion stages.

scholarly journals Free Stream Behavior of Hydrogen Released from a Fluidic Oscillating Nozzle

Fluids ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 245
Author(s):  
Anja Fink ◽  
Oliver Nett ◽  
Simon Schmidt ◽  
Oliver Krüger ◽  
Thomas Ebert ◽  
...  
Keyword(s):  
Free Stream ◽  
Combustion Engine ◽  
Direct Injection ◽  
Combustion Process ◽  
Vertical Direction ◽  
Spray Angle ◽  
Transport Sector ◽  
Flow Measurements ◽  
Injection Process ◽  
Bottom Dead Center

The H2 internal combustion engine (ICE) is a key technology for complete decarbonization of the transport sector. To match or exceed the power density of conventional combustion engines, H2 direct injection (DI) is essential. Therefore, new injector concepts that meet the requirements of a H2 operation have to be developed. The macroscopic free stream behavior of H2 released from an innovative fluidic oscillating nozzle is investigated and compared with that of a conventional multi-hole nozzle. This work consists of H2 flow measurements and injection tests in a constant volume chamber using the Schlieren method and is accompanied by a LES simulation. The results show that an oscillating H2 free stream has a higher penetration velocity than the individual jets of a multi-hole nozzle. This behavior can be used to inject H2 far into the combustion chamber in the vertical direction while the piston is still near bottom dead center. As soon as the oscillation of the H2 free stream starts, the spray angle increases and therefore H2 is also distributed in the horizontal direction. In this phase of the injection process, spray angles comparable to those of a multi-hole nozzle are achieved. This behavior has a positive effect on H2 homogenization, which is desirable for the combustion process.

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