Fuel Injection Research Articles

Effect of Different Fuels on Combustion Instabilities in an Annular Combustor

Abstract Combustion instability in annular combustors of jet engines is a recurring issue. In this study, the characteristics of instabilities for different fuels are investigated by combining the instability maps obtained in a laboratory-scale annular combustor equipped with multiple swirling spray injectors (MICCA-spray) and flame describing functions (FDFs) from a single sector configuration (SICCA-spray). Two types of liquid fuels are injected as hollow cone sprays: heptane, which is fairly volatile, and dodecane, which is less volatile. Experiments are also conducted with gaseous propane, perfectly premixed with air, which serves as a reference. An instability map is systematically drawn by varying the global equivalence ratio and thermal power. The data indicate that the amplitude and frequency of instabilities depend, for the same operating point, on the fuel injection conditions (premixed or spray) and fuel type. Overall trends show that premixed propane is unstable in a broad operating domain. Injection of liquid fuels induces changes in flame time lag that modifies the unstable regions. For heptane, the instability map is closer to the propane reference map, whereas dodecane exhibits wider stable regions. An attempt is made to understand these features by examining the FDF, which gives the ratio of relative fluctuations in heat release rate to the relative fluctuations in velocity. The FDFs measured in a single sector configuration give access to gain and phase information that can be used to determine unstable bands and calculate an instability index guiding the interpretation of the differences in instabilities of the three fuels.

Method and System for Testing the Working Characteristics of Vehicle Fuel Injector

Background: The vehicle fuel injector directly affects the power performance, emission characteristics and economic efficiency of the engine. At present, several testing standards are stipulated on accurate measurement of the working characteristics of fuel injectors. Objective: The purpose of this study is to provide an efficient patent about the method and system for testing the working characteristics of a vehicle fuel injector. Methods: Two key techniques are significant to establish a standard test environment. The patent about the pressure control approach and the injector driving method was proposed. The adaptive fuzzy PID approach was applied to control pressure. An adaptive multi-functional driver was designed and developed for both the voltage-driven and current-driven port fuel injectors. Results: The experiments on the two key technologies were conducted. During the dynamic flow test, the settling time using the system was 1ms. For the static flow test, the settling time was 1 s. The maximum changing rate of pressure fluctuation was 1%. Then, the system was verified by test on the flow characteristics and dynamic response of the voltage-driven and current-driven injectors. The linear deviation of each dynamic flow curve was between ± 3% to ± 6%. Furthermore, the deviation of the dynamic flow curves from the repeated test was small. The maximum deviation of the static flow results was less than 4% and the dynamic response of the injector varied with the change of the pressure. Conclusion: The system meets the requirements of the related standards. The experimental results prove that the system is stable and reliable.

Injection and Atomization of Diesel Fuel and Rapeseed Oil in Diesel Engine

A comparative analysis of properties of petroleum diesel fuel and rapeseed oil is carried out. Numerical studies of the influence of fuel properties on the injection process of fuel are carried out by using ANSYS Fluent. The steady flow of these fuels in the flow channel of an injector nozzle for a 4-stroke turbocharged diesel engine D-245.12S (with cylinder bore-to-stroke ratio 11/12.5) was simulated at the maximum injector needle lift of 0.32 mm. The flow characteristics of petroleum diesel fuel and rapeseed oil - mass fuel consumption, injection velocity, turbulent kinetic energy at the nozzle hole outlet, and the total volume concentration of fuel vapors in the nozzle hole were obtained. The relationship between the turbulent kinetic energy at the nozzle hole outlet and the parameters of the fuel spray fineness is studied. Numerical studies of the relationship between the spray cone angle and the turbulent kinetic energy at the nozzle hole outlet were carried out. A correlation between fuel spraying parameters and the turbulent kinetic energy at the nozzle hole outlet was proposed.

Numerical and Experimental Analysis of Combustion Characteristics of Gas Turbine Engines

Advanced computational fluid dynamics (CFD) methods were used to carry out the numerical analysis. It was created a three-dimensional CFD model to represent the intricate flow and combustion processes inside the gas turbine engine. Fuel injection, combustion kinetics, and the effects of turbulence were all taken into account by the model. In order to analyse several combustion factors, such as temperature distribution, species concentrations, and flame propagation, numerical simulations were run.Experimentation was done in order to verify the numerical results and understand the combustion properties better. To simulate the operational circumstances of a gas turbine engine, a test setup was created. Measurements of combustion parameters, including pressure, temperature, and emissions, were made and compared to the numerical forecasts. The computational model might then be verified and improved as a result.The findings of this study offer insightful information about how gas turbine engines behave during combustion. The temperature distribution, species concentrations, and flame propagation within the engine were all correctly predicted by the numerical models. The experimental observations showed good agreement with the expected values, confirming the accuracy of the numerical model. This thorough examination aids in the comprehension of gas turbine engine combustion processes and can be used as a foundation for future design enhancements and performance enhancements.

Impact of Fuel Injection Distribution on Flame Holding in a Cavity-Stabilized Scramjet

This study investigated the impact of fuel injection distribution on flame stabilization and heat release in a cavity-stabilized scramjet. Experiments were conducted using a hydrogen air heater that provided vitiated air at an average stagnation temperature of 1570 K and stagnation pressure of 12.7 atm, accelerated to a Mach number of 2.2 at the combustor entrance. Ethylene was injected using two fuel injection locations, one upstream of the cavity and another in the cavity. Three different fuel injection distributions were studied for global equivalence ratios of 0.2, 0.3, and 0.4. Measurements included high-speed chemiluminescence and shadowgraph, as well as wall-mounted pressure transducers. It was found that when the cavity fuel flow rate was low, the flame stabilized on the cavity shear layer and resulted in a gradual pressure rise in the combustor. A sufficiently high fuel flow rate in the cavity led to flame stabilization upstream of the cavity, in the fuel jet wake, and a more confined combustion zone. Shadowgraph imaging showed that injection of the fuel from the cavity floor at a sufficient momentum penetrated the shear layer over the cavity and enabled flame propagation upstream of the cavity. It was concluded that the heat release distribution and pressure profile in the combustor could be significantly influenced by the fuel injection distribution through its impact on the flame stabilization mode.

Development of a Small Aviation Two-stroke Kerosene Engine Fuel Injection Controller

Background: The study of kerosene fuel for gasoline engines is of great significance to the supply, management, storage, transportation of military fuel, as well as its safety. A small aviation twostroke kerosene engine fuel injection controller is the key technology of kerosene engines. It is very important to improve the performance of kerosene engine by controlling the air-fuel ratio accurately. Objective: In this study, the initial injection pulse spectrum was firstly obtained by numerical calculation in the absence of kerosene injection pulse spectrum, and then the injection controller was designed based on the initial injection pulse spectrum. Methodology: Firstly, a numerical model of the whole engine was established by using BOOST software. The air mass flow data of the inlet was obtained through numerical calculation. The amount of initial engine fuel injection was calculated according to the requirements of air-fuel ratios in each working condition, from which an initial injection pulse spectrum was obtained. Then, based on Freescale 16-bit embedded micro-controller MC9S12DP512, a kerosene engine fuel injection controller was developed, together with the circuit. According to the initial fuel injection pulse spectrum, a twodimensional interpolation algorithm was developed by using assembly language and C language mixed programming, and the anti-electromagnetic interference ability of the controller was further enhanced. Finally, the accuracy of the initial injection pulse spectrum and the performance and reliability of the injection controller of the kerosene engine were verified by the kerosene engine bench test. Results: The experimental results show that the numerical model was accurate, and the development time of the injection controller reduced by using the numerical model to calculate the initial injection pulse spectra. Conclusion: The developed controller was observed to be stable and reliable, which can meet the control requirement.

Effects of Diesel Fuel Nano-Additives on Friction and Wear Properties of Precision Coupled Parts of a Diesel Engine Fuel Injection System

Due to the unique redox characteristic of CeO2, the addition of CeO2 in diesel fuel reduces diesel engine emissions; however, its influence on the friction and wear performance of fuel injection systems is not clear. In this work, CeO2 was synthesized and modified. CeO2–diesel fuel blends with different concentrations were prepared. The dispersion stability of the CeO2 and modified CeO2 in diesel fuel blends was measured. The results indicated that the dispersion stability of the modified CeO2 in diesel fuel was improved. The effects of adding modified CeO2 to diesel fuel on the friction and wear properties of the fuel injector body were studied. Test results showed that the friction coefficients of all of the diesel fuel blends were the same after running in at normal temperature. At high temperature, the friction coefficients of diesel fuel blends with 10, 25, 50, and 100 ppm CeO2 added were reduced by 14.03, 25.27, 24.31, and 10.58%, respectively, compared with that of neat diesel fuel. Both the width and maximum depth of the wear scar were reduced to different degrees, and the diesel fuel blend dosed with 25 ppm CeO2 had the best antiwear ability at normal temperature and high temperature.HIGHLIGHTSThe morphology of modified CeO2 was spherical and relatively uniform.The dispersion stability of modified CeO2 in diesel fuel was improved.The addition of CeO2 in diesel fuel improved the friction and wear performance.With an increase in CeO2, the range of improvement first increased and then decreased.The diesel fuel blend with 25 ppm CeO2 added showed the best friction and wear performance.

Modern Technologies for Micro-drilling of the Fuel Injector Nozzle used in Motor Vehicles - A Review of the Literature

To cope with the pollution norms and an improvement of the combustion of the internal combustion engines, high-quality holes with diameters smaller than 145 µm are needed for the manufacture of fuel injection nozzles. The current practice of using drilling by electro-discharge machining of fuel injection nozzles is limited in terms of the size of the hole it can efficiently produce and the time required for drilling. In addition, the cost of the tool is high. This paper presents an investigation into a sequential laser and electro-discharge micro-drilling technique for the manufacture of fuel injection nozzles. A pilot hole drilled with a laser is removed by electrodischarge. It was found that this hybrid process eliminated the problems of reformed and heat-affected areas usually associated with the laser drilling process. The new process has allowed a reduction in total drilling time compared to standard electro-discharge machining drilling, as less material is removed from the electro-discharge machining. The quality of the holes is as good as direct electro-discharge machining drilling. This technique has allowed valuable cost savings and increased production capacity for the manufacture of the fuel injector nozzle.

Diagnosing the technical condition of modern diesel injectors using thermal infrared cameras

Fuel injectors are the most damage-sensitive component of the diesel fuel injection system in self-ignition engines. Therefore, an important issue is their diagnosis for the proper assessment of their wear condition. The paper presents a method involving the use of an image from a thermal imaging camera to assess the technical condition of injectors used in common rail injection systems. Four injectors, whose technical condition was known, were tested. Three of them were characterized by a common fault they had damaged control valve seats, while one of the injectors was fully functional. In order to precisely assess their technical condition, the injectors were tested on a test bench. While the injectors were working, the temperature of the body in the place of the control valve was measured at a constant time interval. The conducted research has shown that there is a relationship between the rate of temperature rise of the damaged injectors’ body and their maximum temperatures, and the injection dose expenditure and the overflow expenditure.

Optimization of Combustion Characteristics and Fuel Injection Timing of a New Type Dual-Pit Combustor Rotary Engine

Optimization of Combustion Characteristics and Fuel Injection Timing of a New Type Dual-Pit Combustor Rotary Engine

Experimental and Numerical Investigation on Spray Diffusion and Gas-Fuel Mixing of Ducted Fuel Injection Under Evaporating Conditions

Experimental and Numerical Investigation on Spray Diffusion and Gas-Fuel Mixing of Ducted Fuel Injection Under Evaporating Conditions

Conversion Of Carbureted Fuel Supply Into Electronic Fuel Injection System

Conversion Of Carbureted Fuel Supply Into Electronic Fuel Injection System

Experimental Study of the Addition of Methane in Biomass Gasification Producer Gas in an Optically Accessible Spark Ignition Engine with Port Fuel Injection

Experimental Study of the Addition of Methane in Biomass Gasification Producer Gas in an Optically Accessible Spark Ignition Engine with Port Fuel Injection

吸気管噴射用マルチホールノズルの噴霧微粒化過程（第3 報） -液滴生成過程のモデリング-

吸気管噴射用マルチホールノズルの噴霧微粒化過程（第3 報） -液滴生成過程のモデリング-

Visualization and Simulation Study on Impacts of Wall Roughnesson Spray Characteristics of Ducted Fuel Injection

Visualization and Simulation Study on Impacts of Wall Roughnesson Spray Characteristics of Ducted Fuel Injection

Effect of Fuel Injection Timing and Injection Pressure on Performance in a Hydrogen Direct Injection Engine

Effect of Fuel Injection Timing and Injection Pressure on Performance in a Hydrogen Direct Injection Engine

Present Status of Fusion Fuel Injection System and Neutron Generation

Present Status of Fusion Fuel Injection System and Neutron Generation

Adaptive Backstepping Control of Ship Speed Tracking and Hybrid Mode Selection

Abstract This paper investigates the application of adaptive backstepping control to a hybrid power system for ship propulsion, using a main diesel engine in conjunction with a battery for auxiliary power supply. Fuel injection delay to the diesel engine is estimated based on Pade approximation, and the pure-feedback term in the ship speed dynamics is approximated by Radial Basis Function (RBF) Neural Network. The closed-loop system is proved to be uniformly ultimately bounded.

Study on Characteristics Optimization of Combustion and Fuel Injection of High-Power Diesel Engine Based on Orthogonal Method

Study on Characteristics Optimization of Combustion and Fuel Injection of High-Power Diesel Engine Based on Orthogonal Method

Effects of injection pressure on performance & emission characteristics of CI engine using graphene oxide additive in bio-diesel blend

Abstract In the present study, the effects of graphene oxide (GO) Nanoparticles and Injection Pressures on Performance and Emissions of a diesel engine fueled with Sapota seed biodiesel were investigated. Fuel injection pressure plays a vital role in enhancing engine performance & emission characteristics. Biodiesel's two blends were made with Sapota Seed Oil (10% & 20%) mixed with Diesel (90% and 80%), respectively termed as B10 and B20. The GO Nano-particles of 50 ppm concentration were mixed with these two blends and named as (B10GO50, B20GO50) and later did engine testing with 200 and 220 bar injection pressures. Experiments were performed at a constant 1500 rpm speed at loads of 0, 25, 50, 75, 100 (%), but varying Fuel injection pressures. From the experiments, we obtained values for various parameters, such as BSFC, BTE, Carbon monoxide (CO), Hydrocarbon (HC), Carbon dioxide (CO2), and Nitrogen oxide (NOx). We have noticed from the data that, as the injection pressure rises, the atomization increases. As a result, we observed that NOx Emissions had reduced significantly by 39%. Moreover, we determined less CO and HC emissions in the blends B20GO50 and B10GO50 with 200 and 220 bar than the Diesel. From the Investigation, it can be concluded that biodiesel can be used as an alternative to the diesel engine without any engine modifications.