Injection Engine Research Articles

Shock Propagation Through a Square Injector: Investigation into Rotating-Detonation Engine Injector Dynamics

The rotating detonation engine is perhaps the most promising means to realize pressure-gain combustion in modern engines. The physical processes underpinning the dynamics of the combustion wave are complex, and a lack of understanding of these processes represents a significant barrier to practical implementation of the technology. A significant simplification of the RDE is considered through an abstracted experimental setup. The detonation wave is replaced with a nonreacting shock generated by a shock tube, and the annulus is unwrapped into a single linear channel. Both simplifications make direct visualization of the problem via schlieren imaging tractable. Several performance metrics are used to relate the fluid-dynamic behavior of the shock–injector interaction to the performance of a theoretical rotating detonation engine. The first such metric is “recovery time,” based on the time taken for the injector to return to a fully flowing state after the passage of a detonation wave. The second such metric not only considers the mass flow through the injector exit but also accounts for potential backflow into the injector nozzle that may occur for sufficiently strong waves. Finally, a reactant mass-deficit metric is used to characterize the reduction in mass injection due to the interaction with the wave.

Nb-doped hydrogenated diamond-like carbon coated biodiesel injectors material: Synthesis, structure and properties

Despite the economic and environmental benefits of biodiesel, it poses significant challenges, including coking on metal surface and increased wear on diesel engine injector nozzles. Therefore, this study investigates the synthesis of niobium-doped diamond-like carbon (Nb-DLC) coatings on two types of injector nozzle materials (viz. H13 steel, AISI 420 stainless steel) using the Closed-Field Unbalanced Magnetron Sputtering (CFUBMS) technique. Comprehensive characterizations, including microstructural analysis, crystal structure evaluation, hardness assessment, and tribological property assessment, were conducted. The Nb-DLC coatings demonstrated a stable friction coefficient, with values four times lower than that of the substrate materials. The present findings demonstrate significant enhancements in terms of structural composition, crystalline phase, hardness, friction coefficients, and adhesion properties due to the Nb-DLC coatings. Therefore, Nb-DLC coated materials could be the promising candidate material for biodiesel engine injector nozzle applications. This emphasizes their potential to contribute significantly to the sustainable consolidation of biodiesel within automotive engine.

Waste-recovered quaternary blends: Enhancing engine performance through hydrogen induction by varied injection timing and pressure for sustainable practices

This study explores sustainable energy solutions by utilizing waste-recovered quaternary blends of Scenedesmus obliquus, waste plastics, n-octanol, and hydrogen induction to enhance engine performance. This research aims to address this imperative by proposing a novel blend that not only repurposes waste materials but also leverages hydrogen induction to augment the combustion characteristics of a single cylinder Kirloskar engine's injection timing and injection pressure. The waste plastic is recovered by the pyrolysis method and Scenedesmus obliquus by the transesterification process. The study revealed that out of all the blends, the fuel at 23° before Top Dead Center (bTDC) and 210 bar outperformed all blends with 1.99% better brake thermal efficiency than diesel. The lowest brake specific energy consumption observed was 10.753.35 MJ/kW-hr at 23° bTDC and 240 bar injection pressure, which was 160.38 kJ/kW-hr higher than diesel. Fuel Injection Timing at 23° bTDC at 170 bar shows a 42 ppm decrease for Scenedesmus Obliquus Waste Plastic Octanol 50% (SOWPOCT50) mix compared to diesel. At fuel injection timing (FIT) timing, 23° bTDC and a pressure of 240 bar Injection Pressure (IP), the SOWPOCT50 mixture lowered 0.097 g/h Carbon Monoxide (CO) concentration to diesel. This enormous increase in efficiency and reduction in emission paved a potential replacement source for neat diesel towards the Sustainable Development Goals.

Experimental Investigations of the Hydrogen Injectors on the Combustion Characteristics and Performance of a Hydrogen Internal Combustion Engine

Hydrogen is regarded as an ideal zero-carbon fuel for an internal combustion engine. However, the low mass flow rate of the hydrogen injector and the low volume heat value of the hydrogen strongly restrict the enhancement of the hydrogen engine performance. This experimental study compared the effects of single-injectors and double-injectors on the engine performance, combustion pressure, heat release rate, and the coefficient of variation (CoVIMEP) based on a single-cylinder 0.5 L port fuel injection hydrogen engine. The results indicated that the number of hydrogen injectors significantly influences the engine performance. The maximum brake power is improved from 4.3 kW to 6.12 kW when adding the injector. The test demonstrates that the utilization of the double-injector leads to a reduction in hydrogen obstruction in the intake manifold, consequently minimizing the pumping losses. The pump mean effective pressure decreased from −0.049 MPa in the single-injector condition to −0.029 MPa in the double-injector condition with the medium loads. Furthermore, the double-injector exhibits excellent performance in reducing the coefficient of variation. The maximum CoVIMEP decreased from 2.18% in the single-injector configuration to 1.92% in the double-injector configuration. This result provides new insights for optimizing hydrogen engine injector design and optimizing the combustion process.

Review on Performance and Emissions Characteristics of Compression Ignition Engine Fueling Non-Edible Vegetable Oil

The tremendous exhaustion of resources, a surprising price increase of petroleum fuel and worldwide ecological issues implement to find renewable fuel for compression ignition engine. Non-edible vegetable oils have proven consensus to opt as a replacement for diesel fuel due to comparable properties and less-pollutant characteristics. Using Unmixed Untreated Non-edible Vegetable Oil (UUNVO) in the CI engine matches the needs of a sustainable future and restricts the intensifying cost involved in biodiesel production. This paper aims to review the influence of various UUNVO (Karanja, Jatropha, Neem, Linseed, Mahua and Rubber Seed etc.) on the important performance parameters and emission level of diesel engine. UUNVO can be fuelled to the unmodified CI engine. However, the viscosity of UUNVO is reasonably higher compare to diesel fuel at room temperature, which deteriorates the engine performance and exhaust emission. Minor changes in the injection line for preheating the UUNVO and operating parameters are the way to improve it. It can clearly understand here that preheated UUNVOs typically increase NOx emissions and decrease PM, HC, and CO emissions level compared to standard diesel. UUNVO can substitute diesel fuel completely for short-duration operation. With the long-duration operation, UUNVO produces problems like poor engine performance, injector chocking, and erosion of piston crown, rings, cylinder liner, and other internal parts, and degradation of the lubricant. Problems raised due to durability can be minimized by controlling operational parameters.

Multi-objective cooperation optimization research on dynamic response and energy loss of high-speed solenoid valve for diesel engine injector

The dynamic response and operational reliability of high-speed solenoid valve (HSV) for diesel engine injector are the main indicators to measure their performance. At high-frequency, the eddy current energy and Joule energy generated by the HSV will be converted into heat, which has a significant impact on the service life of HSV. The optimization of HSV involves the interaction between energy loss and the dynamic response of HSV. To optimize the HSV dynamic response time considering energy loss, the HSV work process simulation model was established in this paper, and the model was verified based on armature lift experimental data. Without changing the structural parameters of the HSV, the four parameters of electroconductibility, spring stiffness, damping coefficient, and coil resistance were selected as the key parameters affecting the dynamic response and energy loss. The response surface models (RSMs) of opening response time, closing response time, eddy current energy and Joule energy of the HSV were constructed by using the smoothing spline-analysis of variance method. The multi-objective cooperation optimization of HSV under the interaction of dynamic response characteristics and energy loss was completed by using non-dominated sorting genetic algorithms. After optimization, the opening and closing response times of HSV were reduced by 15.1% and 16.6% respectively, while the eddy current energy and Joule energy were reduced by 5.2% and 48.4% respectively. In this paper, the dynamic response and energy loss were jointly optimized. The presented results provide theory instruction for multi-objective cooperative optimization of HSV.

Development of an ammonia-biodiesel dual fuel combustion engine's injection strategy map using response surface optimization and artificial neural network prediction

The study intends to calibrate the compression ignition (CI) engine split injection parameters as efficiently. The goal of the study is to find the best split injection parameters for a dual-fuel engine that runs on 40% ammonia and 60% biodiesel at 80% load and a constant speed of 1500 rpm with the CRDi system. To optimize and forecast split injection settings, the RSM and an ANN model are created. Based on the experimental findings, the RSM optimization research recommends a per-injection timing of 54 °CA bTDC, a main injection angle of 19 °CA bTDC, and a pilot mass of 42%. As a result, in comparison to the unoptimized map, the split injection optimized calibration map increases BTE by 12.33% and decreases BSEC by 6.60%, and the optimized map reduces HC, CO, smoke, and EGT emissions by 15.68%, 21.40%, 18.82, and 17.24%, while increasing NOx emissions by 15.62%. RSM optimization with the most desirable level was selected for map development, and three trials were carried out to predict the calibrated map using ANN. According to the findings, the ANN predicted all responses with R > 0.99, demonstrating the real-time reproducibility of engine variables in contrast to the RSM responses. The experimental validation of the predicted data has an error range of 1.03–2.86%, which is acceptable.

Deep convolutional autoencoders for the time–space reconstruction of liquid rocket engine flames

The integration of high-fidelity numerical simulations into the rocket engine design-cycle promises to cut costs in an ever more competitive launch market. Although still being intractable in the optimization of most of combustion devices, their potential can be harnessed via appropriate reduced order models (ROMs). In recent years, significant progress has been made in the ROM literature through the adoption of non-linear methods, coming from the realm of deep learning. These methods promise to deliver where conventional linear techniques, such as Proper Orthogonal Decomposition (POD), fall short due to their inherent qualities.In the current work, we carry out a first attempt to develop purely data-driven emulators for a shear-coaxial liquid rocket engine injector. In particular, a Convolutional Neural Network autoencoder (CNN-AE) with a Multi-Layer Perceptron (MLP) latent dynamics encoder architecture is considered. The main objective is to assess the capacity of autoencoders based models to reconstruct, in time and space, the instantaneous temperature field of a non-canonical, complex, reactive, flow configuration. The data used is made of Large Eddy Simulations (LES) of three distinct, real-life inspired, injector configurations.The autoencoder based models show superior reconstruction capabilities compared to POD with similar latent-space dimension. Moreover, the time–space reconstructed fields preserve the spectral content of the snapshots, with only a small loss in gain at high frequencies. These results serve as proof-of-concept for further developments on surrogate models of liquid rocket engine injectors.

ИССЛЕДОВАНИЕ ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ АЛЬТЕРНАТИВНЫХ СЫРЬЕВЫХ ИСТОЧНИКОВ В КАЧЕСТВЕ ЭНЕРГОНОСИТЕЛЕЙ ДЛЯ ДВС

The areas of application of synthetic oil fractions and fatty acid methyl esters (FAME) were determined. Conducted: Research on two types of alternative fuels has been carried out: 1 – various fractions of synthetic oil obtained using the Fischer-Tropsch method; 2 – mixed fuels (B7) based on hydrotreated petroleum diesel fraction with the addition of 7% FAME of rapeseed oil. The prospects for their use as an additive to petroleum fuels are shown based on the results of tests of various fractions of synthetic oil. Since the main disadvantages of biodiesel and mixed fuels are poor oxidative stability and a tendency to form deposits, studies of the effectiveness of the antioxidant additive Agidol-1 in mixed fuel with the addition of 7% rapeseed oil FAME under test conditions on an OSV-M non-engine unit were carried out. The positive effect of the antioxidant additive Agidol-1 on the reduction of high-temperature deposits on the bottoms of injectors when operating on mixed fuels containing up to 7% FAMEs has been established. Quantitative assessment of deposits on the bottom of the spray nozzle was carried out using an FT-801 IR-Fourier spectrometer with a wide-range infrared microscope. Based on the results obtained at OSV-M using IR-Fourier spectrometry, the promise of using the antioxidant additive Agidol-1 to reduce deposits on the injectors of engines operating on mixed fuels was shown.

Analysis of Changes in the Opening Pressure of Marine Engine Injectors Based on Vibration Parameters Recorded at a Constant Torque Load.

This article deals with the problems related to the difficulties in the vibration diagnostics of modern marine engines. The focus was on the injection system, with a particular emphasis on injectors. An unusual approach to the implementation of research enabling the smooth regulation of the opening pressure of the mechanical injector during engine operation at a constant load was presented. This approach obtained repeatability of conditions for subsequent measurements, which is very difficult to achieve when using the classic approach that forces the injector to be disassembled after each test.

Quasi-Two-Dimensional Simulation of a Rotating Detonation Engine Combustor and Injector

A numerical simulation of an annular rotating detonation engine with stoichiometric hydrogen–oxygen is performed. A generic, well-posed, and easily implemented approach using a quasi-two-dimensional method to model the area variations through the rotating detonation engine’s injector and combustor is presented. The detonation–injector interaction is studied for the case with a ratio of four between the combustor and injector’s throat areas. A shock wave is formed in the divergent portion of the injector due to the high backpressure created by the detonation in the combustor. A Favre-averaged steady-state analysis of stream lines and particle paths reveals that the shock causes an irrecoverable loss of stagnation pressure. Stagnation pressure gain in the combustor is insufficient to make up for the loss, and the flow leaves the engine with lower stagnation pressure than in the plenum.

Homogeneous Field Measurement and Simulation Study of Injector Nozzle Internal Flow and Near-Field Spray

The homogeneous field measurement of internal flow and spray of internal combustion engine injector nozzles under high pressure has always been one of the difficulties in experimental research. In this paper, an actual-size aluminum alloy nozzle is designed, and the simultaneous measurement of internal flow and near-field spray is successfully realized with the help of synchrotron radiation X-ray phase contrast imaging technology under an injection pressure of 30~90 MPa. For a 0.25 mm aperture nozzle, different radii of the inlet corner can induce different cavitation layer thicknesses, and the measured flow section shrinkage ratio is 0.70. The flow characteristics in the nozzle are entirely connected to the jet characteristics, indicating a tight correlation between internal flow and jet morphology. Finally, the internal cavitation of the nozzle was studied by the CFD simulation, and the simulation results are in good agreement with the experiment.

Analysis of the structure of the atomized fuel spray with marine diesel engine injector in the early stage of injection

This paper presents the results of the experimental research of the atomized fuel spray with the marine diesel engine injector in the constant volume chamber. The specificity of the phenomena occurring in the marine engine cylinder was the reason to use the optical visualisation method in the studies – the Mie scattering technique. This work presents an analysis of the influence of different geometry of outlet orifice and opening pressures of marine diesel injector on the macrostructure of the fuel spray. In the results, it was observed that the increased L/D ratio of the outlet orifice of the injector caused: an increase in the spray cone angle and a decrease in the spray tip penetration in the early stage of injection. Furthermore, it was defined that the characteristic of spray tip penetration over time was power, whereas the spray cone angle over time was a logarithmic function.

Numerical Study of Ammonia Spray with a GDI Engine Injector

With the aim of expanding the knowledge on liquid ammonia sprays, this paper investigates the injection process of ammonia through Computational Fluid Dynamics (CFD) using the Lagrangian particle method, within the Reynolds Averaged Navier Stokes (RANS) approach for turbulence modeling. Numerical results and experimental data are compared in terms of liquid and vapor tip penetration, local values of Sauter Mean Diameter (SMD) and global spray morphology. This model validation process allows to build a predictive simulation framework for ammonia injection. In order to explore also the flash boiling phenomenon, results of CFD simulations of ammonia spray and the comparison with experimental data are presented for different conditions, ranging from non-flashing regimes to flash boiling conditions. Breakup model constants need to be markedly tuned for each regime, and established values for traditional fuels, like gasoline, appear not to work well with ammonia. Ultimately, this study highlights that capturing spray local details (such as local SMD values) across all the regimes with a single model or setup is still challenging, especially with a new fuel such as ammonia, whose properties differ by a large amount from more established values for hydrocarbons.

Production of HHO gas in the water-electrolysis unit and the influences of its introduction to CI engine along with diesel-biodiesel blends at varying injection pressures

Hydrogen has been identified as a clean and renewable energy source that has a significant potential to replace fossil fuels. The effective production of hydrogen on a commercial scale, however, presents a vital obstacle in today's world. Water splitting electrolysis, which offers high energy conversion and storage capabilities, has emerged as a promising approach for achieving the efficient hydrogen production to address this issue. This experimental research focuses on the production of hydrogen-oxygen gas through the electrolysis process. HHO gas provides promising benefits in terms of better combustion and lower emissions. Therefore, it also focuses on how best HHO gas can be utilized in diesel engines to improve the performance and to reduce the emissions. HHO gas produced at 60 L per hour through electrolysis process is mixed with air in a mixing chamber. Also, Palm munja methyl ester of 10% and diesel fuel of 90% was volumetrically blended to get B10 biodiesel. Therefore, totally four test fuels (Diesel, Diesel + HHO, B10, and B10 + HHO) were tested on a single-cylinder Kirloskar water-cooled direct injection diesel engine under different engine speeds ranging from 1447 to 1550 rpm. The engine injector pressure was varied from 200, 220, and 240 bar during the experiments with an interval of 20 bar. The engine has been modified for hydrogen and oxygen inlet at the entrance manifold 6 cm away at an angle of 30°. The results shows that at 200 bar injection pressure with B10 + HHO blend exhibits better performance and released lower emissions. The performance results also show that the brake thermal efficiency was improved up to 14.16%, and the brake power was increased by 3.22%, while the brake-specific fuel consumption is reduced by 11.53%. The emission results show that CO, HC, NOx, and CO2 emissions were reduced by 20.87%, 11.47%, 1.96%, and 5.22%, respectively. Therefore, it can be concluded that B10 + HHO provides better performance and the lowest emissions compared with other blends.

Potential of ethanol and butanol in reducing deposits of DISI engine injectors

The operation of conventional (hydrocarbon) fuels causes certain effects in the internal combustion engine. Despite the satisfactory efficiency of internal combustion engines, their fuel systems, particularly the injectors, are subject to constant fouling. The article analyzes the possibility of reducing the deposit of high-pressure gasoline injectors using the alcohol addition of ethanol and butanol. The study was conducted under the engine and non-engine conditions. Fuel injection timing was analyzed when fueling with different mixtures, and non-engine analyses were conducted to determine changes affecting the injectors. The results indicate the possibility of reducing injector hole coking using ethanol and butanol as a 20% additive to the base fuel.

Investigation of full-scale porous injector plate transpiration cooling coupled with combustion in high-thrust H2/O2 rocket engines

The high chamber pressure and large heat flux impose greater demands on the structure cooling and thermal protection of the future high-thrust H2/O2 rocket engine. To investigate the applicability of transpiration cooling on the full-scale injector plate in the high-thrust rocket engine, a numerical model is presented, in which the porous region and the mainstream hot gas region are directly coupled. The local equilibrium model and eddy dissipation model are considered. The numerical model is validated by transpiration cooling experiments for a subscale rocket engine injector plate. Then, the numerical simulation of transpiration cooling for the high-thrust H2/O2 rocket engine injector plate shows that the transpiration cooling with 13% of the total hydrogen mass flow rate can reduce the gas side temperature of the injector plate by about 150 K and reduce the thermal penetration depth to 9.2% of the plate thickness. Moreover, As the coolant mass flow rate increase from 4% to 13%, the gas side temperature of the plate decreases from 735 K to 668 K and the cooling effectiveness rises. The lower the coolant inlet temperature, the lower the plate temperature, but the higher the cooling effectiveness. Besides, the plate temperature drops with the decreases of the thermal conductivity of the porous media.

Analysis Of Injector Flowing On Auxiliary Engine On KMP. Portlink

Auxiliary Engine is an engine in which air is compressed to a high enough temperature to ignite diesel fuel injected into the cylinder, where combustion and emission drive pistons which convert the chemical energy in the fuel into mechanical energy. Good fogging is needed in diesel engines, in order to get maximum power. The condition of the injectors on the Auxiliary Engine greatly affects the condition of the Auxiliary Engine itself. The presence of injector damage can affect the operating conditions of the Auxiliary Engine, so the condition of the injectors must always be maintained. The research method that the author uses in the preparation of this thesis is a qualitative research method as a data analysis technique to analyze the problems that exist in the Auxiliary Engine, namely what factors cause injector damage to the Auxiliary Engine, the impact and what efforts are made to overcome these factors. Of these problems by systematically identifying various factors on human factors, environment, methods, machines to formulate strategies to be taken. Based on the results of research that has been done by the author on the ship KMP. PORTLINK, it can be concluded that the damage to the injector on the Auxiliary Engine is caused by two factors, namely the high operational schedule of the ship, and the infrequent maintenance of the Auxiliary Engine injector and the use of inappropriate fuel. To overcome these factors, maintenance can be carried out according to PMS time, as well as good filtering on low-quality fuel. Based on the results of research that has been done by the author on the ship KMP. PORTLINK, it can be concluded that the damage to the injector on the Auxiliary Engine is caused by a clogged nozzle and looseness in the injector component.

Effect of fuel injection timing on performance and emissions with a dedicated direct injector in a hydrogen engine

In this study, hydrogen fuel was injected directly into a cylinder using a prototype of a dedicated hydrogen direct injector (HDI). The effects of fuel injection timing and amount of hydrogen fuel injected on engine output performance and emissions (e.g., nitrogen oxides and carbon dioxide) were investigated by varying the fuel injection timing from before top dead center (BTDC) 190 crank angle degree (CAD) toward BTDC 60 CAD. Strategies for maximizing the engine’s output performance when an after-treatment system for nitrogen oxide removal catalysts is not used were assessed. When using the HDI, a torque improvement result (up to 35.9%) can be obtained even under the condition that the hydrogen supply pressure was half as low as compared to the case of using a gasoline direct injector for hydrogen fuel. Under the condition of retarded fuel injection timing, a locally rich mixture is formed to increase the emission of nitrogen oxides at a level of 50 ppm or higher. The engine oil is burned to affect the emission of carbon dioxide (CO2), which is proportional to the load.

Limitations of cetane number to predict transient combustion phenomena in high-pressure fuel sprays

Fundamental understanding of in-cylinder processes in diesel engines is important to screen emerging biofuels and advanced combustion modes that can reduce greenhouse gas emissions and regulated pollutants including soot. In this study, the role of fuel properties on spray development and combustion is investigated by systematically isolating chemical and thermophysical effects. Three different fuels are considered, two with similar chemical properties and two with similar thermophysical properties with one fuel common to both groups. Experiments are performed in a constant-pressure flow chamber designed to provide stable test conditions and facilitate acquisition of at least 150 injections in quick succession for each fuel under reacting high-pressure, high-temperature ambient conditions using a modified conventional diesel engine injector. High speed optical diagnostics including rainbow schlieren deflectometry, OH* chemiluminescence, and a two-color pyrometry system are employed to simultaneously image the transient spray and reacting jets. Image analysis is performed to determine liquid length, vapor penetration length, timing and location of first stage and main ignition events, lift-off location, total soot mass, and more. Results show that fuels with similar chemical properties or cetane number (CN) exhibit similar delay times for first stage and main ignition events as may be expected, but very different liquid length, first stage and main ignition locations, lift-off length, apparent turbulent flame speed, and soot formation. As such, the ability to characterize candidate biofuels with CN or other parameters derived from simple flame configurations is called into question. In this study, thermophysical properties controlling the liquid length are identified as the main contributing factor for the observed differences.