Comparison of Spray Formation of a Multi and a Single Hole Gasoline Direct Injector

2021 ◽  
Author(s):  
Malki Maliha ◽  
Heiko Kubach ◽  
T. Koch
Keyword(s):  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Computing Time ◽  
Fuel Mixture ◽  
Nozzle Geometry ◽  
Experimental Investigations ◽  
Fuel Temperature ◽  
Fuel Mass ◽  
Spray Formation

Abstract Direct injection in internal combustion engines is often realized with a multi hole injector which forms a spray pattern consisting of multiple jets with a small distance between their origin. This leads to an interaction of adjacent spray jets. The spray characteristic is significantly influenced by this interaction, and can considerably change the fuel evaporation and with it the emission behavior with varying number of holes or hole nozzle geometry [8]. Experimental investigations, especially if a good optical access to a single jet is necessary, often needs to use a comparable injector with a reduced number of holes. In addition to that, 3D-CFD simulation models can also use a reduction of spray jet number for a partial consideration of fuel mixture to reduce the computing time. For these cases a determination of the correlation between spray formation and reduced nozzle holes is important. In this work the spray patterns of an original 6-hole gasoline DI-injector and, after closing of 5 holes, the resulting 1-hole injector were compared. The fuel mass flow through one hole can change due to a change of hydrodynamic effects inside the nozzle and leads to a correcting factor for the injecting time, to get comparable fuel mass flows. The penetration depth, droplet speed, size and spatial distribution were measured. Additional investigations of the influence of the fuel pressure and fuel temperature were carried out.

Qualitative Estimation Criterion of Direct Injection Diesel Engines Performance Prediction for Stationary and Industrial Applications

2014 ◽  
Vol 659 ◽  
pp. 205-210
Author(s):  
Vladimir Mărdărescu ◽  
Nicolae Ispas ◽  
Mircea Nastasoiu
Keyword(s):  
Diesel Engines ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Internal Combustion ◽  
Industrial Applications ◽  
Nozzle Geometry ◽  
Technical Solution ◽  
Test Bed ◽  
Injection Pump

Our approach is to define as accurately as possible, the opportunities of forecasting the environmental and energetically qualities of direct injection Diesel engines for stationary and industrial applications. This research requires the validation of new energy solutions or injection process. Knowing that test bench research of internal combustion engines is a task that requires highly qualified personnel and very expensive equipment for investigate the combustion process, a research program to define the best technical solution involves significant costs. The energetically solution of an internal combustion engine, similar to those examined in this paper, is defined by the following guidelines and parameters: - Control of mixture formation; - Compression ratio; - Average swirl intake number channel; - Geometry of the intake and exhaust cams; - Diagram of distribution; - Drive cam type injection pump; - Geometry of the combustion chamber; - Type and nozzle geometry (sack configuration and l / d ratio ); - Needle stroke; - The diameter and length of the injection pipe; - Amount of injector opening pressure (for hydraulic injectors); - Type of delivery valve; - Time of injection. Based on experience gained during the test at the test bed, we proposed a criterion for assessing qualitative performance of Diesel class discussed above. This criterion refers to environmental and energetically performance, as a prediction of performance at nominal regime, after shorten tests with cold engine.

scholarly journals NUMERICAL ANALYSIS OF THE AIR-FUEL MIXTURE IN INDIRECT AND DIRECT INJECTION OF FOUR-STROKE ENGINES

2019 ◽  
Vol 18 (2) ◽  
pp. 89
Author(s):  
G. G. Narcizo ◽  
D. A. Miranda
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Direct Injection ◽  
Fuel Mixture ◽  
Combustion Efficiency ◽  
Simulation Software ◽  
Injection System ◽  
Scholarly Work ◽  
Ansys Fluent ◽  
Dynamics Simulations

The quality of the air-fuel mixture in internal combustion engines directly affects the combustion efficiency, therefore a good design of the combustion chamber combined with the correct fuel injection system, can provide a better use of this mixture and increase the efficiency of the engine. Considering these aspects, this scholarly work presents a comparative study of the indirect injection system and direct fuel injection, analyzing the way the mixture behaves in these two conditions. For this, the Ansys Fluent simulation software was used, in which were applied computational fluid dynamics simulations of the air-fuel mixture. The objective of this scholarly work is to contribute to the development of the injection systems, enabling the improvement of new studies and developments of new nozzle models can be performed.

scholarly journals Inner Selective Non-Catalytic Reduction Strategy for Nitrogen Oxides Abatement: Investigation of Ammonia Aqueous Solution Direct Injection with an SI Engine Model

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2742
Author(s):  
Fengshuo He ◽  
Xiumin Yu ◽  
Yaodong Du ◽  
Zhen Shang ◽  
Zezhou Guo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Nitrogen Oxides ◽  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Catalytic Reduction ◽  
Fluid Dynamic ◽  
Direct Injection ◽  
Ammonia Nitrogen ◽  
Ammonia Content ◽  
Engine Model

This study contributes to a method based on an aqueous solution of ammonia direct injection for NOx emissions control from internal combustion engines. Many previously published studies about deNOx technology are based on selective catalytic reduction (SCR), but only few deal with inner selective non-catalytic reduction (inner SNCR) technology, which is an intensive improvement of selective non-catalytic reduction (SNCR) applied in the in-cylinder purification procedure. Before numerical calculations were carried out, the computational fluid dynamic (CFD) simulation model was validated with steady-state experimental results. The main results revealed that with the increasing concentration of aqueous solution of ammonia, nitrogen oxides gradually decrease, and the largest decline of NOx is 65.1% with little loss of cylinder peak pressure. Unburned hydrocarbon (UHC) and carbon monoxide (CO) may increase using inner SNCR, and soot emissions show a decreased tendency. However, there is little change when ammonia content varies. Ulteriorly, refining the direct injection phase is of great help to inner SNCR technology to enhance the reduction of NOx and reduce NH3 oxidation and NH3 slipping.

Modeling Sealing in Transient Injector Simulations

2017 ◽  
Author(s):  
Chinmoy Mohapatra ◽  
Gabriel Jacobsohn ◽  
Eli Baldwin ◽  
David Schmidt
Keyword(s):  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Fuel Injection ◽  
Direct Injection ◽  
Internal Flow ◽  
Adaptive Mesh ◽  
Small Cells ◽  
Valve Lift ◽  
Needle Valve ◽  
Computational Domain

The early and late portions of transient fuel injection have proven to be a rich area of research, especially since the end of injection can create a disproportionate amount of emissions in direct injection internal combustion engines. A perennial challenge in simulating the internal flow of fuel injectors is the valve opening and closure event. In a typical adaptive-mesh CFD simulation, the small gap between the needle valve and the seat must be resolved with very small cells, resulting in extremely expensive computations. Capturing complete closure usually involves a topological change in the computational domain. In this work we present a more gradual and easily-implemented model of closure that avoids spurious water-hammer effects. The algorithm is demonstrated with a simulation of a gasoline direct injector operating under cavitating conditions. The results include the the first simulation of a multiple injection event known to the authors. The results show cavitation at low valve lift. Further, they reveal post-closure dynamics that result in dribble, which is expected to contribute to unburned hydrocarbon emissions.

Nozzle for Oscillating Direct Injection in H2 Internal Combustion Engines

MTZ worldwide ◽  
2021 ◽  
Vol 82 (7-8) ◽  
pp. 42-45
Author(s):  
Bernhard Bobusch ◽  
Thomas Ebert ◽  
Anja Fink ◽  
Oliver Nett
Keyword(s):  
Internal Combustion Engines ◽  
Direct Injection ◽  
Internal Combustion ◽  
Combustion Engines

scholarly journals Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2729
Author(s):  
Ireneusz Pielecha ◽  
Sławomir Wierzbicki ◽  
Maciej Sidorowicz ◽  
Dariusz Pietras
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Injection System ◽  
Rapid Compression Machine ◽  
Process Indicators ◽  
Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

Effect of altitude conditions on combustion and performance of a turbocharged direct-injection diesel engine

2021 ◽  
pp. 095440702110262
Author(s):  
Zhentao Liu ◽  
Jinlong Liu
Keyword(s):  
Diesel Engine ◽  
High Altitude ◽  
Diesel Engines ◽  
Direct Injection ◽  
Pressure Rise ◽  
Ambient Conditions ◽  
Allowable Limit ◽  
Spray Formation ◽  
Direct Injection Diesel Engine ◽  
And Performance

Market globalization necessitates the development of heavy duty diesel engines that can operate at altitudes up to 5000 m without significant performance deterioration. But the current scenario is that existing studies on high altitude effects are still not sufficient or detailed enough to take effective measures. This study applied a single cylinder direct injection diesel engine with simulated boosting pressure to investigate the performance degradation at high altitude, with the aim of adding more knowledge to the literature. Such a research engine was conducted at constant speed and injection strategy but different ambient conditions from sea level to 5000 m in altitude. The results indicated the effects of altitude on engine combustion and performance can be summarized as two aspects. First comes the extended ignition delay at high altitude, which would raise the rate of pressure rise to a point that can exceed the maximum allowable limit and therefore shorten the engine lifespan. The other disadvantage of high-altitude operation is the reduced excess air ratio and gas density inside cylinder. Worsened spray formation and mixture preparation, together with insufficient and late oxidation, would result in reduced engine efficiency, increased emissions, and power loss. The combustion and performance deteriorations were noticeable when the engine was operated above 4000 m in altitude. All these findings support the need for further fundamental investigations of in-cylinder activities of diesel engines working at plateau regions.

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.

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