scholarly journals Numerical study for the spray characteristics of diesel engine powered by biodiesel fuels under different injection pressures

Author(s):  
Mohamed F. Al-Dawody ◽  
◽  
Khaled A. Al-Farhany ◽  
Naseer H. Hamza ◽  
Dhafer A. Hamzah ◽  
...  

Great attention is directed towards the study of the spray phenomena theoretically and experimentally due to its dramatic effect on the combustion process that occurred in an internal combustion engine, in particular, the diesel engine. The spray macroscopic characteristic of diesel engines fueled with two different biodiesel fuels in addition to nominal diesel under various injection pressures has been investigated numerically in this work. The selected biofuels are Rapeseed methyl ester (RME), Waste cooking oil methyl ester (WCOME). The Russian simulation software Diesel-RK is used in this work. Four different injection pressures are used which are 200, 500, 800 and 1000 bar respectively. It is found that RME has higher spray penetration with a narrow spray angle due to high viscosity and large momentum compared to diesel fuel. The results reported that biodiesels have greater Sauter mean diameter (SMD) compared to pure diesel because of their higher viscosity and surface tension. Promising reduction in SMD comes with WCOME as the injection pressure increases. Cylinder pressure along with heat release is reduced in the case of biodiesel due to the reduction in heating values. The lowest ability to produce smoke is recorded for WCOME where 93% reduction is achieved followed by a 57% reduction for RME as compared to diesel. The obtained results are compared with the results of other researcher and the convergence between them is observed.

Author(s):  
Luigi Allocca ◽  
S. Alfuso ◽  
A. Montanaro ◽  
G. Valentino ◽  
M. Lolli

In this paper a comparative investigation between two different injectors for Common Rail diesel apparatus has been carried out in terms of transient response and spray pattern for different injection strategies. Performances of an innovative Magneti Marelli (MM) gasoline derived injector have been evaluated against the Bosch generation injectors for multiple strategies. Both injectors have operated on an automotive apparatus controlled by a Programmable Electronic Control Unit to set injection strategies in terms of pulses number, duration and dwell time. The working mode of the two injectors is completely different: the Bosch injector is activated by the inner fuel hydraulic circuit while the Magneti Marelli one operates a direct control of the needle lift through the solenoid currents. The Bosch nozzle characteristics are 5 holes, 150° spray angle, and 0,13 mm diameter. The MM injector main characteristics are low hydraulic losses, simple component structure and ready use of the fuel at the nozzle opening being able to control small fuel flow rates (0.1 mg/str) in the injection pressures range 20–70 MPa. The geometry of the nozzle is quite similar to the Bosch one being a 5 hole, 150° spray angle, 0.12 mm diameter. Single, pilot+main and pilot+split main strategies have been explored for the two injectors at 50 and 60 MPa injection pressures investigating the spray behavior for two amounts of injected fuel (5.0 and 6.5 mg/str). The systems have been characterized in terms of injected fuel rate as well spatial and temporal behavior of the emerging jets from the nozzle. Images of the spray have been collected by a synchronized CCD camera at different time from the start of injection. The jets have evolved in an optically accessible high pressure vessel at ambient temperature as well in an optically accessible single-cylinder 2-stroke Diesel engine extracting the fuel spray parameters from the collected images applying a digital processing techniques. Due to the diverse mechanism of the injector actuation, a different temporal and spatial fuel distribution has been registered for the two apparatuses. These could strongly influence the air/fuel mixture formation and combustion process with effect on the emissions. Preliminary engine tests performed on a light duty direct injection diesel engine, equipped with the MM injector, have highlighted the potential of the MM injector to handle acceptable engine performances.


Author(s):  
Jagdish Nargunde ◽  
Chandrasekharan Jayakumar ◽  
Anubhav Sinha ◽  
Naeim A. Henein ◽  
Walter Bryzik ◽  
...  

An investigation was conducted on a 0.42 liter single cylinder diesel engine equipped with a common rail fuel injection system to evaluate the influence of the swirl motion on JP-8 fuel combustion. Engine tests were performed under steady state conditions of 5 bar IMEP and 1500 RPM. Two different swirl ratios of 1.44 and 7.12 were applied at injection pressures ranging from 400 to 1200 bar. The apparent rate of heat release (ARHR) curve is analyzed to determine the effect of swirl on combustible mixture formation, auto-ignition, premixed and diffusion controlled combustion fractions. An attempt is made to correlate between the swirl ratio and different combustion and emissions parameters at different injection pressures. The emissions included the gaseous fractions and particulates. Two types of particulate matter were measured: Accumulation mode particles (AMPs) and Nucleation mode particles (NMPs). The results indicate that ignition delay duration of JP-8 increases as the swirl ratio increases influencing the overall combustion process and engine out emissions.


Fluids ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 245
Author(s):  
Anja Fink ◽  
Oliver Nett ◽  
Simon Schmidt ◽  
Oliver Krüger ◽  
Thomas Ebert ◽  
...  

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.


Author(s):  
Jonathan Dolak ◽  
Deep Bandyopadhyay

The objective of this research was to optimize an Electro-Motive Diesel (EMD) large-bore, two-cycle diesel engine (710 cubic inches of displacement per cylinder) at high load to minimize soot, nitrogen oxide (NOx) and fuel consumption. The variables considered were the number of spray-hole nozzles per injector, including spray angle and piston bowl geometry, for a range of injection pressures. Analytical simulations were conducted for a calibrated EMD 710 Tier 2 engine and a few of the top-performing cases were studied in detail. CONVERGE™, a commercially available, advanced combustion simulation software was used in this analysis. A surface deforming tool, Sculptor®, was used to obtain various piston bowl geometries. MiniTab® was utilized for statistical analysis. Results show that optimal combinations of injection variables and piston bowl shape exist to simultaneously reduce emissions and fuel consumption compared to Tier 2 EMD 710 engines. These configurations will be further tested in a single-cylinder test cell and presented later. This investigation shows the importance of bowl geometry and spray targeting on emissions and fuel consumption for large-bore, two-stroke engines with high power density.


2013 ◽  
Vol 744 ◽  
pp. 35-39
Author(s):  
Lei Ming Shi ◽  
Guang Hui Jia ◽  
Zhi Fei Zhang ◽  
Zhong Ming Xu

In order to obtain the foundation to the research on the Diesel Engine YN4100QB combustion process, exhaust, the optimal design of combustion chamber and the useful information for the design of exhaust muffler, the geometric model and mesh model of a type internal combustion engine are constructed by using FIRE software to analyze the working process of internal combustion engine. Exhaust noise is the main component of automobile noise in the study of controlling vehicle noise. It is primary to design a type of muffler which is good for agricultural automobile engine matching and noise reduction effect. The present car mufflers are all development means. So it is bound to cause the long cycle of product development and waste of resources. Even sometimes not only can it not reach the purpose of reducing the noise but also it leads to reduce the engine dynamic. The strength of the exhaust noise is closely related to engine combustion temperature and pressure. The calculation and initial parameters are applied to the software based on the combustion model and theory. According to the specific operation process of internal combustion engine. Five kinds of common operation condition was compiled. It is obtained for the detailed distribution parameters of combusted gas temperature pressure . It is also got for flow velocity of the fields in cylinder and given for the relation of the parameters and crankshaft angle for the further research. At the same time NOx emissions situation are got. The numerical results show that not only does it provide the 3D distribution data in different crank shaft angle inside the cylinder in the simulation of combustion process, but also it provides a basis for the engine combustion ,emission research, the optimization design of the combustion chamber and the useful information for the designs of muffler.


2021 ◽  
pp. 146808742110442
Author(s):  
Sebastian Welscher ◽  
Mohammad Hossein Moradi ◽  
Antonino Vacca ◽  
Peter Bloch ◽  
Michael Grill ◽  
...  

Due to increasing climate awareness and the introduction of much stricter exhaust emission legislation the internal combustion engine technology faces major challenges. Although the development and state of technology of internal combustion engines generally reached a very high level over the last years those need to be improved even more. Combining water injection with a diesel engine, therefore, seems to be the next logical step in developing a highly efficient drive train for future mobility. To investigate these potentials, a comprehensive evaluation of water injection on the diesel engine was carried out. This study covers >560 individual operating points on the test bench. The tests were carried out on a single-cylinder derived from a Euro 6d four-cylinder passenger car with the port water injection. Furthermore, a detailed pressure trace analysis (PTA) was performed to evaluate various aspects regarding combustion, emission, etc. The results show no significant effects of water injection on the combustion process, but great potential for NOx reduction. It has been shown that with the use of water injection at water-to-fuel rates of 25%, 50%, and 100%, NOx reduction without deterioration of soot levels can be achieved in 62%, 40%, and 20% of the experiments, respectively. Furthermore, water injection in combination with EGR offers additional reduction in NOx emissions.


2021 ◽  
Vol 312 ◽  
pp. 07022
Author(s):  
Alfredo Lanotte ◽  
Vincenzo De Bellis ◽  
Enrica Malfi

Nowadays there is an increasing interest in carbon-free fuels such as ammonia and hydrogen. Those fuels, on one hand, allow to drastically reduce CO2 emissions, helping to comply with the increasingly stringent emission regulations, and, on the other hand, could lead to possible advantages in performances if blended with conventional fuels. In this regard, this work focuses on the 1D numerical study of an internal combustion engine supplied with different fuels: pure gasoline, and blends of methane-hydrogen and ammonia-hydrogen. The analyses are carried out with reference to a downsized turbocharged two-cylinder engine working in an operating point representative of engine operations along WLTC, namely 1800 rpm and 9.4 bar of BMEP. To evaluate the potential of methane-hydrogen and ammonia-hydrogen blends, a parametric study is performed. The varied parameters are air/fuel proportions (from 1 up to 2) and the hydrogen fraction over the total fuel. Hydrogen volume percentages up to 60% are considered both in the case of methane-hydrogen and ammonia-hydrogen blends. Model predictive capabilities are enhanced through a refined treatment of the laminar flame speed and chemistry of the end gas to improve the description of the combustion process and knock phenomenon, respectively. After the model validation under pure gasoline supply, numerical analyses allowed to estimate the benefits and drawbacks of considered alternative fuels in terms of efficiency, carbon monoxide, and pollutant emissions.


2014 ◽  
Vol 543-547 ◽  
pp. 425-428
Author(s):  
Jian Ying Dai ◽  
Dong Ling Xiao

In the paper firstly analyzes the engine combustion theory, for the numerical analysis for engine cylinder pressure to provide the basis. This paper makes use of the FIRE simulation software to analyze the shrinkage mouth combustion engine under different working condition of the fuel injection advance Angle of the characteristics of the combustion process and exhaust process, after got the mixture combustion in cylinder gas pressure range and emissions, for the next step muffler simulation model is established by applying the method of finite element and acoustical noise analysis provides the basis of the parameters, shorten product development cycle.


Author(s):  
M. Yilmaz ◽  
H. Koten ◽  
M. Zafer Gul

Nowadays, automotive industries focused on clean diesel combustion in their combustion processes are investigated for their potential to achieve near zero particulate and NOx (Nitrogen oxides) emissions. Their main disadvantages are increased level of unburned hydrocarbons (HC) and carbon monoxide (CO) emissions, combustion control at high load, power output and limited operating range. The simulation of the air flow, spray and combustion in an internal combustion engine were prepared for a single cylinder of a nine-liter, six cylinder diesel engine. Many times the geometry is complex because moving pistons and valves are involved, which makes it difficult to generate structured mesh. In-cylinder spray-air motion interaction, a Lagrangian multiphase model has been applied in a heavy-duty CI engine under direct injection conditions. A comprehensive model for atomization of liquid sprays under high injection pressures has been employed. Three dimensional CFD calculations of the intake, compression and power strokes have been carried out with different spray angle, spray profile and start of injection. A new combustion model ECFM-3Z (Extended Coherent Flame Model) developed at IFP is used for combustion modeling. Finally, a calculation on an engine configuration with compression, spray injection and combustion in a direct injection Diesel engine is presented. In this study, exhaust emissions, and particularly the emission of NOx, CO and soot derived from premixed combustion are investigated, and the relationship between combustion and emission characteristics are showed. The calculated CFD simulation in different combustion cases was compared. The cases were prepared by changing the parameters: start of injection, spray angle and spray profile. Modeling of combustion proposed in the present study can be outlined as follows. NOx concentration is decreased by combustion of a over lean-mixture modeled by the pre-injection. Most of pre-mixture is combusted by main-injection, and therefore the amount of pre-injection and main-injection come into prominence. The results are greatly in agreement qualitatively with the previous experimental and computational studies in the literature.


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