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Viewing 1 to 30 of 5822
2015-04-14
Technical Paper
2015-01-0861
Matthew Younkins, Margaret S. Wooldridge, Brad A. Boyer
Hydrogen fueled internal combustion engines have potential for high thermal efficiencies; however, high efficiency conditions can produce high nitrogen oxide emissions (NOx) that are challenging to treat using conventional 3-way catalysts. This work presents the results of an experimental study to reduce NOx emissions while retaining high thermal efficiencies in a single-cylinder research engine fueled with hydrogen. Specifically, the effects on engine performance of the injection of water into the intake air charge were explored. The hydrogen fuel was injected into the cylinder directly. Several parameters were varied during the study, including the amount of water injected into the intake charge, the amount of fuel injected, the phasing of the fuel injection, the number of fuel injection events, and the ignition timing. The results were compared with expectations for a conventionally operated hydrogen engine where load was controlled through changes in equivalence ratio.
2015-04-14
Technical Paper
2015-01-1730
Luca Romani, Giovanni Vichi, Giovanni Ferrara, Francesco Balduzzi, Paolo Trassi, Jacopo Fiaschi, Federico Tozzi
High specific fuel consumption and pollutant emissions are the main drawbacks of the small crankcase-scavenged two-stroke engine. The symmetrical timing of the scavenging ports combined with a carburetor or an indirect injection system leads to a lower scavenging efficiency than a four-stroke engine and to the short-circuit of fresh air-fuel mixture. The use of fuel supply systems as the indirect injection and the carburetor are the standard solutions for a small two-stroke engine equipment, due to necessity of reducing the complexity, weight, overall dimensions and costs. This paper presents the results of a detailed study on the application of an innovative Low Pressure Direct Injection system (LPDI) to an existing 300 cc cylinder formerly equipped with a carburetor. The proposed solution is characterized by two injectors working at 5 bar of injection pressure.
2015-04-14
Technical Paper
2015-01-0857
Valentin Soloiu, Martin Muinos, Spencer Harp
In this study, a Premixed Charge Compression Ignition (PCCI) obtained by sequential dual fueling strategy of n-butanol port fuel injection (PFI) and direct injection of ULSD#2 was investigated against binary mixtures combustion (defined as premixed in the tank) of n-butanol and ultra-low sulfur diesel (ULSD#2) with the same n-butanol to diesel ratios (35%, 50%, 65% by mass) in an omnivorous compression ignition engine. The hypothesis of the study is that combustion phasing (respectively CA50) can be successfully controlled by the above named strategies. Both fueling strategies controlled the high reactivity of the ULSD#2 and slowed down the chemical reactions with the low cetane number fuel, n-butanol. These processes led to fuel reactivity stratification and an increase in the ignition delay observed as the amount of n-butanol increased.
2015-04-14
Technical Paper
2015-01-0672
Douglas Marriott, Takeshi Ohtomo, Tohru Wako
Predicting sloshing noise as early as possible during the design process has become an increasingly desired simulation for fuel tank suppliers. It enables suppliers to build products directly to customer specifications, at the minimum cost, in a shorter timeframe. Ideally, it needs to be run during the quote stage to avoid hidden obstacles later. The procedure to accurately and efficiently analyze sloshing noise has to date not been fully established and instead relies mostly on indirect acceleration readings to deduce the noise levels. In this paper, we introduce a new technique to analyze the sloshing noise generated in the fuel tank of an automobile to take advantage of the acoustic analysis software using infinite element and finite element methods. This technique is performed by chaining the different software for the analysis of the sloshing behavior and acoustic response together for a multi-discipline simulation result.
2015-04-14
Technical Paper
2015-01-1647
Matthieu Lecompte, Stephane Raux, Jerome Cherel, Vivien Delpech
Euro VI standards for heavy duty vehicles require the use of a DPF in order to fulfill the particulate matter threshold. Although passive regeneration of soot by NO2, promoted by a DOC located upstream the DPF, is preferred, the use of an active regeneration might be required whenever the DPF soot mass trapped increases. Some manufacturers made the choice a fuel injection in the exhaust system in order to generate an exothermic reaction in the DOC that helps to regenerate the particulate filter. This dedicated circuit avoids the use of post-injection which may induce oil dilution by diesel. The DPF regeneration is efficient and the DOC works durably if the exhaust diesel spray is completely vaporized before entering DOC and thoroughly mixed with the exhaust gases. However, ensuring complete evaporation and an optimum mixture distribution in the exhaust line is challenging.
2015-04-14
Technical Paper
2015-01-0831
Wonah Park, Youngchul Ra, Eric Kurtz, Werner Willems, Rolf D. Reitz
The low temperature combustion concept is very attractive for reducing NOx and soot emissions in diesel engines. However, it has potential limitations due to higher combustion noise and CO and HC emissions. A multiple injection strategy is an effective way to reduce unburned emissions and noise in LTC. In this paper, the effect of multiple injection strategies was investigated to reduce combustion noise and unburned emissions in LTC conditions. A hybrid surrogate fuel model was developed and validated, and was used to improve LTC predictions. Triple injection strategies were considered to find the role of each pulse and then optimized. The split ratio of the 1st and 2nd pulses fuel was found to determine the ignition delay. Increasing mass of the 1st pulse reduced unburned emissions and an increase of the 3rd pulse fuel amount reduced noise. It is concluded that the pulse split ratio can be used as a control factor for emissions and noise.
2015-04-14
Technical Paper
2015-01-0847
Xiao Ma, Haoye Liu, Yanfei Li, Zhi Wang, Hongming Xu, Jian-Xin Wang
Stoichiometric Dual-fuel Compression Ignition (SDCI) combustion has good potential both in emission control and thermal efficiency. It was found that split injection of diesel can effectively enlarge the controllable range in combustion phase control and increase the flexibility in the fuel selection. This study focuses on the effects of split injection strategies at low and mid loads in SDCI mode. The impacts of split ratio, the pilot and main injection timing are studied, including their interaction with the available maximum gasoline-to-diesel ratio. The simplified principles of the fuel supply strategy design was promoted to avoid complicated multi-factor optimization. Generally, larger percent of the pilot injection at an early crank angle results in better PM emissions, but the main injection duration should be long enough to supply proper amount of diesel for an optimized combustion phase.
2015-04-14
Technical Paper
2015-01-1731
Yanxiang Yang, Bingqian Tan, Changwen Liu, Ping Zhang, Daguang Xi
Fuel supply unit for small engine management system usually has two ends, pump and injector, in which fuel is mostly metered by controlling the injector and pump is driven mechanically or electrically to produce injection pressure. This paper presents a pump-end control technology for pump-nozzle fuel supply unit, in which the pump is driven and controlled electrically for pressurizing and metering the fuel fed into an engine. The fuel supply unit is composed of a solenoid driven plunger pump and an auto-open nozzle, and it is directly driven by PWM signals from ECU. The pump and nozzle are connected with a high-pressure fuel tube of a length in a large scope. For such a fuel supply unit, the PWM pulse time T1 actuated on the solenoid can only be co-related to the fuel injected amount with large errors because too many factors may affect the result.
2015-04-14
Journal Article
2015-01-0830
Jesus Benajes, Ricardo Novella, Daniela De Lima, Pascal Tribotte
Partially Premixed Combustion (PPC) of fuels in the gasoline octane range has proven its potential to achieve simultaneous reduction in soot and NOX emissions, combined with high indicated efficiencies; while still retaining proper control over combustion phasing with the injection event, contrary to fully premixed strategies. However, the octane range where the ignition properties of a given fuel are optimum depends on the engine operating conditions. Gasoline fuels with high octane number as the commonly available for the public provide a challenge to ensure reliable ignition especially in the low load range, while fuel blends with lower octane numbers present problems for extending the ignition delay in the high load range and avoid the onset of knocking-like combustion. Therefore, it is essential to choose an appropriate fuel and injection strategy to resolve these issues to assure successful PPC operation in the full engine map.
2015-04-14
Journal Article
2015-01-1727
Francesco Balduzzi, Giovanni Vichi, Luca Romani, Giovanni Ferrara, Paolo Trassi, Jacopo Fiaschi, Federico Tozzi
High specific fuel consumption and pollutant emissions are the main drawbacks of the small crankcase-scavenged two-stroke engine. The symmetrical timing of the scavenging ports combined with a carburetor or an indirect injection system leads to a lower scavenging efficiency than a four-stroke engine and to the short-circuit of fresh air-fuel mixture. The use of fuel supply systems as the indirect injection and the carburetor are the standard solutions for a small two-stroke engine equipment, due to necessity of reducing the complexity, weight, overall dimensions and costs. This paper presents the results of a detailed study on the application of an innovative Low Pressure Direct Injection system (LPDI) to an existing 300 cc cylinder formerly equipped with a carburetor. The proposed solution is characterized by two injectors working at 5 bar of injection pressure.
2015-04-14
Journal Article
2015-01-0967
Tingjun Hu, Ho Teng, Xuwei Luo, Bin Chen
Turbocharged gasoline direct injection (GTDI) engines have a flat torque curve with the maximum torque covering a wide engine speed range. Increasing the high-speed-end torque for a GTDI engine provides better acceleration performance to the vehicle powered by the engine but it also leads to longer injection durations to deliver the fuel requested. In this study, results are reported of experimental investigation of impact of fuel injection on dilution of the crankcase oil for a highly-boosted GTDI engine lubricated with SAE 5W30 synthetic engine oil. It is found that the high-speed-end torque for the GTDI engine has a significant influence on fuel dilution because longer injection durations result in impingement of large fuel drops on the piston top and considerable levels of fuel dilution. Test results indicate that the higher the torque at the rated-power, the higher the level of fuel dilution.
2015-04-14
Journal Article
2015-01-0597
Christian Schulz, Tamara Ottenwaelder, Thomas Raffius, Thorsten Brands, Thomas Huelser, Gerd Grunefeld, Stefan Pischinger
Maintaining low NOx emissions over the operating range of diesel engines continues to be a major issue. However, optical measurements of nitric oxide (NO) are lacking particularly in the core of diesel jets, i.e. in the region of premixed combustion close to the spray axis. This is basically caused by severe attenuation of both the laser light and fluorescent emission in laser-induced fluorescence (LIF) applications. Even in non-sooting flames, ultraviolet (UV) light is strongly absorbed by combustion intermediates and products. However, the absorption decreases generally with increasing wavelength. Laser-output extinction is therefore reduced by using a KrF* excimer laser in this work, which provides tunable radiation at about 248 nm. By contrast, laser wavelengths around 226 nm were employed in most previous applications. Extinction of both laser light and LIF emission are additionally reduced by keeping absorption path lengths relatively short in this work.
2015-04-14
Journal Article
2015-01-0521
Yong-Yuan Ku, Ta-Wei Tang, Ko Wei Lin, Steven Chan
With the development of world economy, the shortage in the supply of oil energy as well as the greenhouse effect have become a public concern around the world. The application of biodiesel on vehicle transportation has become the focus of development in many countries. Biodiesel, Fatty Acid Methyl Esters (FAME), is made during the process of transesterification of the animal and vegetable oils. Compared with fossil diesel, biodiesel has some characteristics, such as organic acid, higher water saturation, and oxygen content. From the results of the literatures [1] to [5], it showed that biodiesel would cause the inflation of some plastic and flexible products and the corrosion of metal materials. Metal fuel tanks have the characteristics of high flammability, high impact resistance, and good workability and are often used in commercial vehicles. The corrosion of metal materials is a natural chemical change and it can be influenced by the environment.
2015-04-14
Technical Paper
2015-01-0925
Erik Elmtoft, A. S. (Ed) Cheng, Nick Killingsworth, Russell Whitesides
Injection spray dynamics is known to be of great importance when modeling turbulent multi-phase flows in compression-ignition engines. Two key aspects of spray dynamics are liquid breakup and penetration, both of which are affected by the initial sizes of the injected droplets. In the current study, injection of n-heptane is characterized with droplet sizes smaller than the 100 μm nozzle diameter by using a uniform distribution based on the Sauter Mean Diameter (SMD). This is done for a RANS RNG k-ε turbulence model with a minimum grid size of 125 μm and for a LES-Viscosity turbulence model with a minimum grid size of 62.5 μm. The turbulence models are validated against non-reacting experimental data from the Engine Combustion Network (ECN). Multiple realizations are also performed for LES-Viscosity to represent individual experimental injections. The results show that multi-phase physics of sprays can be adequately captured when the initial size distribution is chosen appropriately.
2015-04-14
Technical Paper
2015-01-0950
Jonas Galle, Roel Verschaeren, Sebastian Verhelst
The need for simulation tools for the internal combustion engine is becoming more and more important due to the complex engine design and increasingly strict emission regulation. This implies models that are able to give more accurate results while keeping the time efforts for calculations at an acceptable level. Fuels consist of a complex mixture of different molecules which cannot realistically be handled in computations. Simplifications are required and are realized using fuel surrogates. The main goal of this work is to show that the choice of the surrogates is of importance if simplified models are used and that the performance strongly depends upon the sensitivity of the fuel properties that refer to the main model hypotheses. This is important as this is usually not taken into consideration by modelers. As a consequence of these influences, too much tuning needs to be done to match experiments with the modeling.
2015-04-14
Journal Article
2015-01-0870
Gabriel Ingesson, Lianhao Yin, Rolf Johansson, Per Tunestal
Gabriel Ingesson, Yin Lianhao, Rolf Johansson, Per Tunestål August 30, 2014 Abstract The combustion timing in internal combustion engines aects fuel consumption, in cylinder peak pressure, engine noise and emission levels. The combination of an in cylinder pressure sensor together with a direct injection fuel system lends itself well for cycle to cycle control of the combustion timing. This paper presents a method of controlling combustion timing by the use of a cycle to cycle injection timing algorithm. At each cycle the current estimated rate of heat release is used to predict the in cylinder pressure changes due to a combustion timing shift. The prediction is then used to obtain a cycle to cycle model that relates combustion timing to indicated mean effective pressure, max pressure and max pressure derivative. Injection timing is then decided by solving an optimization problem involving the obtained model.
2015-04-14
Journal Article
2015-01-0883
Yoshihiro Imaoka, Kiyotaka Shouji, Takao Inoue, Toru Noda
Technologies for improving the fuel economy of gasoline engines have been vigorously developed in recent years for the purpose of reducing CO2 emissions. Increasing the compression ratio for improving thermal efficiency and downsizing the engine based on fuel-efficient operating conditions are good examples of technologies for enhancing gasoline engine fuel economy. A direct-injection system is adopted for most of these engines. Direct injection can prevent knocking by lowering the temperature through fuel evaporation in the cylinder. Therefore, direct injection is highly compatible with downsized engines that frequently operate under severe supercharging conditions for improving fuel economy as well as with high compression ratio engines for which susceptibility to knocking is a disadvantage. On the other hand, direct-injection engines have certain issues such as the need to reduce particulate matter (PM) emissions, and technical measures must be developed for that purpose.
2015-04-14
Technical Paper
2015-01-0878
Guanzhang He, Hui Xie
A two stage turbocharging system is adapted to simulate the power turbine that is installed downstream the charging turbine to further recover waste energy in the exhaust. The potential of energy recovery from the exhaust gas is investigated. The effect of two important controllable factors including injection timing and position of VGT (variable geometry turbocharger) vanes is studied though experiments. The overall fuel consumption benefit, fuel energy distribution, and link efficiency along the energy flow path are involved in the analysis. It is found that total power output of whole system can be enhanced when the exhaust gas is adequate corresponding to the high speed and load engine operating condition. The energy recovered will be counteracted or even less than the power loss of the original engine when low speed and load running condition is considered. The increment of pumping loss plays the dominant role in limiting the further enhancement of total power.
2015-04-14
Technical Paper
2015-01-1163
Gabriel Elias, Stephen Samuel, Alessandro Picarelli
This study details the investigation into the hybridization of engine ancillary systems for 2014+ Le Mans LMP1-H vehicles. This was conducted in order to counteract the new strict fuel-limiting requirements governing the powertrain system employed in this type of vehicles. Dymola 1D vehicle simulation software was used to construct a rectilinear vehicle model with complete ancillary system, and a map based 3.8L, V8, engine and its associated ancillary systems, including oil pumps, water pump and fuel pump and a powertrain system with a full kinetic energy recovery system (KERS) strategy. Appropriate validation strategy was implemented to validate the model. A validated model was used to study the difference in fuel consumption for the conventional ancillary drive off of the internal combustion engine in various situational tests and a hybrid-electric drive for driving engine ancillaries.
2015-04-14
Technical Paper
2015-01-1264
Junseok Chang, Yoann Viollet, Abdullah Alzubail, Amir Faizal Naidu Abdul-Manan, Abdullah Al Arfaj
This paper explores the potential for reducing transport-related greenhouse gas (GHG) emissions by introducing high-efficiency spark-ignition engines with a dual-fuel injection system to customize octane of the fuels based on real-time engine requirements. Recent study [1] shows that 4-6% GHG emissions can be reduced by replacing 2/3 light duty vehicle fleet with high efficiency engines that are designed with higher compression ratio and boost levels. However, this can be only possible if premium gasoline fuel (Research Octane Number, RON=98 or 100) is readily available on a large scale to supply a fleet demand. From a refinery perspective, increasing the octane of the fuels to such high levels could potentially require significant and costly upgrades to the reforming and isomerization units as well as lower gasoline yield, and thus, this is not an economically attractive option for many of the refiners. In our study, we considered different strategy.
2015-04-14
Journal Article
2015-01-0936
Andrew Swantek, Alan Kastengren, Daniel Duke, Zak Tilocco, Nicolas Sovis, Christopher F. Powell
Abstract Recent advancements in x-ray radiography diagnostics for direct injection sprays at Argonne's Advanced Photon Source have allowed absorption measurements of individual spray events, in addition to ensemble-averaged measurements. These measurements offer insight into the shot-to-shot variation of these sprays in the near-nozzle, spray formation region. Three single hole diesel injectors are studied across various injection and ambient pressures, spanning 14 different conditions. We calculated two dimensional maps of the standard deviation in line of sight mass distribution between individual spray events. These illuminated the spatial and temporal extent of variability between spray events. Regions of large fluctuations were observed to move downstream during the initial spray period and reached a steady state location after this initial transient.
2015-04-14
Technical Paper
2015-01-0938
Prashanth Karra, Thomas Rogers, Petros Lappas
The air entrainment process of a compressed natural gas transient fuel jet was investigated in a constant-volume chamber using Schlieren and particle image velocimetry (PIV) techniques. Jet to ambient pressure ratios of 20, 40, and 60 were tested. In each test, nitrogen was used to fill the chamber as an air surrogate before the jet of natural gas was injected. Schlieren high speed videography and PIV experiments were performed at the same conditions. Schlieren mask images were used to accurately identify the jet boundary which was then superimposed onto a PIV image. Vectors adjacent to the Schlieren mask in the PIV image were used to calculate the spatial distribution of the air entrainment at the jet boundary. The effects of ambient density and injection pressure on the air entrainment and contour shape at various parts of the jet are investigated.
2015-04-14
Technical Paper
2015-01-0934
Pascal Tetrault, Etienne Plamondon, Matthieu Breuze, Camille Hespel, Christine Mounaïm-Rousselle, Patrice Seers
Abstract In this paper, a semi-empiric fuel spray tip penetration model is proposed. It is applied to single and double injection strategies taking into account the early and far field penetration. The model is based on the momentum flux as initially proposed by [1] for single injection but it is derived from mean mass flow rate herein. Fuel spray interaction with entrainment air is taken into account for the second injection. The proposed model is calibrated and validated using data from 9 experiments conducted with an indirect piezoelectric diesel injector under various injection strategies. The experiments included 1) injection rate measurements using the Bosch method to determine mean mass flow rate during injector opening as well as obtaining injection duration which are both entry parameters to the model; 2) Fuel spray tip penetrations were measured in a pressure vessel using high speed photography for single and double injection strategies.
2015-04-14
Technical Paper
2015-01-0935
Leonid Tartakovsky, Ran Amiel, Vladimir Baibikov, Mark Veinblat
Abstract This study considers one of the challenges that arise during conversion of gasoline SI engines to ‘heavy fuel’ feeding - worsening engine performance because of intensive fuel film formation on inner surfaces of the intake manifold. A main goal of this study was investigation of an interaction process of a single fuel drop and a fuel jet with the impingement surface. Ultrasonic (US) oscillation of the latter was applied to prevent fuel film formation. Diesel fuel was chosen for our experiments because it causes more problems of mixture formation in SI engines. In the series of experiments with a single drop, effects of the drop size, ultrasound performance and a type of the impingement surface on the drop behavior were studied using a high-speed photography. In experiments with a fuel jet the phenomena of fuel film formation and size distribution of the impinging and reflected droplets were studied using a high-speed photography and PDPA/LDV technique.
2015-04-14
Technical Paper
2015-01-0917
Alessandro Montanaro, Michela Costa, Ugo Sorge, Luigi Allocca
Abstract The work analyses, from both an experimental and a numerical point of view, the impingement of a spray generated from a GDI injector on a hot solid wall. The temperature of the surface is identified as an important parameter affecting the outcome after impact. A gasoline spray issuing from a customized single-hole injector is characterized in a quiescent optically-accessible vessel as it impacts on an aluminum plate placed at 22.5 mm from the injector tip. Optical investigations are carried out at atmospheric back-pressure by a direct schlieren optical set-up using a LED as light source. A synchronized C-Mos high-speed camera captures cycle-resolved images of the evolving impact. The spatial and temporal evolution of the liquid and vapor phases are derived. They serve to define a data base to be used for the validation of a properly formulated 3D CFD model suitable to describe the impact of the fuel on the piston head in a real engine.
2015-04-14
Technical Paper
2015-01-0924
Joseph Camm, Richard Stone, Martin Davy, David Richardson
A model for the evaporation of a multi-component fuel droplet is presented that takes account of temperature dependent fuel and vapour properties, evolving droplet internal temperature distribution and composition, and enhancement to heat and mass transfer due to droplet motion. The effect on the internal droplet mixing of non-ideal fluid diffusion is accounted for. Activity coefficients for vapour-liquid equilibrium and diffusion coefficients are determined using the UNIFAC method. Both well-mixed droplet evaporation (assuming infinite liquid mass diffusivity) and liquid diffusion-controlled droplet evaporation (iteratively solving the multi-component diffusion equation) have been considered.
2015-04-14
Technical Paper
2015-01-0913
Ryo Uchida, Daisuke Tanaka, Toru Noda, Shinya Okamoto, Keiji Ozawa, Tsuneaki Ishima
In a direct injection gasoline engine, the impingement of injected fuel on the oil film, i.e. cylinder liner gives rise to various problems such as abnormal combustion, oil dilution and particulate matter emission. Therefore, in order to solve these problems, it is necessary to have a clear understanding of the impingement behavior of the fuel spray onto the oil film. However, there is little information on the impingement behavior of the fuel droplet onto the oil film, whereas many investigations on the impingement behavior of the fuel droplet onto the fuel film are reported. In this study, fundamental investigations were performed for the purpose of clarifying the impingement behavior of the fuel spray onto the oil film. A single fuel droplet mixed with fluorescence dye was dripped on the oil film. To separately measure the fuel and the oil after impingement, simultaneous Mie scattering and laser-induced fluorescence (LIF) methods were performed.
2015-04-14
Technical Paper
2015-01-0949
Mathis Bode, Tobias Falkenstein, Vincent Le Chenadec, Seongwon Kang, Heinz Pitsch, Toshiyuki Arima, Hiroyoshi Taniguchi
Compared to conventional injection techniques, Gasoline Direct Injection (GDI) has a lot of advantages such as increased fuel efficiency, high power output and emissions levels, which can be more accurately controlled. Therefore, this technique is one of the major topics of today's injection system research. The performance of GDI systems depends on multiple physical processes. The internal flow and the mixing of the coherent liquid stream with the gaseous ambient environment are two examples. Studying these processes is very difficult due to the overall complexity and the involved small length and time scales. Especially the region just after exiting the nozzle, where the primary breakup occurs, is experimentally hardly accessible, but a clear understanding of this region is particularly important, because primary breakup affects multiple other physical processes.
2015-04-14
Technical Paper
2015-01-0946
Yongjin Jung, Julien Manin, Scott Skeen, Lyle M Pickett
A variation in spreading angle of diesel spray from a 3-hole nozzle injector was seen by a long distance microscopy in non-reacting and non-evaporating conditions. The variation from an axial single-hole injector with a nominally identical nozzle size does not occurred in non-reacting or reacting conditions. To investigate the effect of the variation in the spreading angle, liquid penetration length were measured by the Mie scattering in a horizontal configuration to avoid a temperature gradient within the combustion vessel. In addition, the diffused back illumination (DBI) was applied to the vertically injected configuration after matching an ignition delay in both configurations to be similar. Schlieren was employed to quantity the penetration and the spreading angle of vapor jet. The liquid penetration increased gradually after a rapid ramp-up region and starts a hump at around 600 us, which corresponds to the convergence of the spreading angle.
2015-04-14
Technical Paper
2015-01-0948
Le (Emma) Zhao, Ahmed Abdul Moiz, Jeffrey Naber, Seong-Young Lee, Sam Barros, William Atkinson
Liquid spray breakup and atomization, two multi-phase phenomena, strongly affect the ignition and combustion processes. High-speed jet-to-jet impingement in water sprays could be an effective phenomenon for the spray propagation and droplet vaporization. To achieve higher vaporization efficiency, impingement from two-hole nozzles is analyzed in this paper. This paper focuses on investigating vaporization mechanism as a function of the impingement location and the collision breakup process provided by two-hole impinging jet nozzles. CFD (Computational Fluid Dynamics) is adopted to do simulation. Lagrangian model is used to predict jet-to-jet impingement and droplet breakup conditions while KH-RT breakup and O’Rourke collision models are implemented for the simulation.
Viewing 1 to 30 of 5822