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Viewing 1 to 30 of 5837
2015-04-14
Technical Paper
2015-01-1163
Gabriel Elias, Stephen Samuel, Alessandro Picarelli
Abstract 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 vehicle. Dymola 1D vehicle simulation software was used to construct a rectilinear vehicle model with a map based 3.8L V8 engine and its associated ancillary systems, including oil pumps, water pump and fuel pump as well as a full kinetic energy recovery system (ERS). 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
2015-01-1350
Peng Liu, Liyun Fan, De Xu, Xiuzhen Ma, Enzhe Song
Abstract High-speed solenoid valve (HSV) is one of the most critical components of electronic control fuel system for diesel engine, whose dynamic response characteristics have a direct impact on the key performance indicators of diesel engine. For the improvement of dynamic response speed of HSV, a design method of multi-objective optimization based on response surface methodology and genetic algorithm (GA) is employed. Firstly, the finite element model (FEM) of HSV was developed and verified. Secondly, the second order polynomial response surface model (RSM) of the electromagnetic force was constructed by the method of optimal latin hypercube design along with the FEM of HSV, taking the key structural parameters of armature and iron core as variables. Then the multi-objective optimization mathematical model (MOMM) of HSV based on RSM was analyzed and established, taking the electromagnetic force and the mass of armature as objectives.
2015-04-14
Technical Paper
2015-01-1270
Philip Anderson, Mohammed Aslam, Partab Jeswani
Abstract In the current state of the art automotive fuel pumps there is only one channel on each side of the impeller. For high flow and pressure applications the size of such pumps becomes excessive. In order to reduce the size to a manageable level it may be necessary to have two or more channels on each side. But the problem with a multichannel pump is that the peak efficiency of each channel happens at a different operating point and the overall pump efficiency may not be that good. This problem can be overcome by synchronizing the channels. In a synchronous pump the channel diameter and cross sectional area of channels are such that the peak efficiency happens at the same operating point and the overall pump efficiency is improved. In this paper we derive the governing equations for flow, pressure and efficiency and layout a methodology for synchronizing the channels.
2015-04-14
Technical Paper
2015-01-1267
Jae-Cheon Lee, Hao Liu, Yoo-Jeong Noh, Hyun Myung Shin, Yong Nam Shin, Myung Kweon Kang
Abstract A high-pressure fuel pump in a GDI (Gasoline Direct Injection) engine has been increasingly applied on passenger vehicles because of its high fuel efficiency and reduction of exhaust emissions. The design specifications of principal components of GDI high-pressure pump should be validated prior to the manufacturing. This study presents the analytical results of the specifications for the design of a GDI pump of Motonic Co. by using computational model based simulation. The results are largely divided into two parts. First, cam-follower dynamics with the proper design of cam profile, and second, the discharge flow performance of the pump in consideration of the characteristics of inlet control valve.
2015-04-14
Technical Paper
2015-01-1273
Shunsuke Aritomi, Hiroyasu Kuniyoshi, Kenichirou Tokuo, Satoshi Usui, Atsuji Saito, Yuta Saso
Abstract A recent trend in high-pressure gasoline pumps is increasing the outlet pressure. One of the most important topics for increasing this pressure is improving volumetric efficiency. Therefore, the purpose of this research is to quantify the breakdown of efficiency loss factors and to suggest a new design for improving volumetric efficiency. Authors developed a method of quantifying the efficiency loss breakdown of high-pressure gasoline pumps by using 1D fluid pressure simulation results and conducting evaluation experiments regarding sensitivity. Authors separated pump movement into three phases; suction, compression, and delivery. Authors then investigated the loss factors in each phase. As a result, authors obtained an equation for predicting the final output volume. The equation consists of a limit output volume and other types of leakage volumes.
2015-04-14
Technical Paper
2015-01-1730
Luca Romani, Giovanni Vichi, Giovanni Ferrara, Francesco Balduzzi, Paolo Trassi, Jacopo Fiaschi, Federico Tozzi
Abstract High specific fuel consumption and pollutant emissions are the main drawbacks of the small crankcase-scavenged two-stroke engine. The symmetrical port timing 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 is the standard solution for small two-stroke engine equipment, due to the 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) on an existing 300 cm3 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
2015-01-1731
Yanxiang Yang, Bingqian Tan, Changwen Liu, Ping Zhang, Daguang Xi
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, is studied. The unit is composed of a solenoid driven plunger pump, a high-pressure fuel tube, and an auto-open nozzle, and only the pump is propelled by PWM power from an ECU. To achieve a higher metering accuracy, a metering theory deciding the fuel discharging rate was developed by studying the system using a physical-mathematical model. The developed so called T3 theory makes the fuel supply unit with excellent metering consistency under various conditions, which can meet the requirement of fuel supply unit application to small engine management system. The study reveals that an electrically characterized variable, T3, which is associated with the net output energy, can directly results in a mass discharge.
2015-04-14
Technical Paper
2015-01-0749
J. Sureshkumar, Ganesan Venkitachalam, J M Mallikarjuna, R Elayaraja
Abstract In gasoline direct injection (GDI) engines, air-fuel mixture homogeneity plays a major role on engine performance, especially in combustion and emission characteristics. The performance of the engine largely depends on various engine operating parameters viz., start of injection, duration of injection and spark timing. In order to achieve faster results CFD is becoming a handy tool to optimize and understand the effect of these parameters. Therefore, this study aims on evaluating the two injection parameters viz., single and split injection to evaluate different flame characteristics. Novelty in this study is to define five different parameters which are called α, β, γ, δ and η the details of which are explained in the paper. In order to understand the flame characteristics, these five parameters are found to be very useful.
2015-04-14
Technical Paper
2015-01-0831
Wonah Park, Youngchul Ra, Eric Kurtz, Werner Willems, Rolf D. Reitz
Abstract 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, 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 distribution 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
Abstract Stoichiometric dual-fuel compression ignition (SDCI) combustion has superior potential in both emission control and thermal efficiency. Split injection of diesel reportedly shows superiority in optimizing combustion phase control and increasing flexibility in fuel selection. This study focuses on split injection strategies in SDCI mode. The effects of main injection timing and pilot-to-total ratio are examined. Combustion phasing is found to be retarded in split injection when overmixing occurs as a result of early main injection timing. Furthermore, an optimised split injection timing can avoid extremely high pressure rise rate without great loss in indicated thermal efficiency while maintaining soot emission at an acceptable level. A higher pilot-to-total ratio always results in lower soot emission, higher combustion efficiency, and relatively superior ITE, but improvements are not significant with increased pilot-to-total ratio up to approximately 0.65.
2015-04-14
Technical Paper
2015-01-0393
Alessandro d'Adamo, Fabio Berni, Sebastiano Breda, Mattia Lugli, Stefano Fontanesi, Giuseppe Cantore
Abstract Engine downsizing is gaining popularity in the high performance engine market sector, where a new generation of highly downsized engines with specific power outputs around or above 150 HP/litre is emerging. High-boost and downsizing, adopted to increase power density and reduce fuel consumption, have to face the increased risks of pre-ignition, knock or mega-knock. To counterbalance autoignition of fuel/air mixture, such engines usually operate with high fuel enrichments and delayed (sometimes negative) spark advances. The former is responsible for high fuel consumption levels, while the latter reduces performance and induces an even lower A/F ratio (below 11), to limit the turbine inlet temperature, with huge negative effects on BSFC.
2015-04-14
Technical Paper
2015-01-0458
Subrata Sarkar, Sudarshan Kumar, Atul Singhal, Surbhi Kohli, Kailash Golecha, Jubin George
Abstract The objective of this paper is to provide a robust design solution for a Jet pump which is used for fuel removal from an Active Drain Liquid Trap (ADLT). This jet pump can work for both Gasoline and Diesel based automobiles. The major focus area of this paper, is improvement in the robustness of Jet pump performance parameters, such as motive flow and induced flow. A design study for such a two fuel application was first initiated using Taguchi's robust design approach. In order to reduce the inventory complexity and cost, a common design possibility was then addressed. Two approaches for robust design have been discussed, namely the Taguchi Methodology (Orthogonal Cross Array based design) and the Dual RSM (Response Surface Methodology) Technique. Results show that the Dual RSM provides improved performance with reduced variation, as compared to Taguchi's approach.
2015-04-14
Technical Paper
2015-01-0857
Valentin Soloiu, Martin Muinos, Spencer Harp
Abstract 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
2015-01-0861
Matthew Younkins, Margaret S. Wooldridge, Brad A. Boyer
Abstract 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
2015-01-0747
Aimin Du, Zhongpan Zhu, Chuanchuan Chu, Mengmeng Li
Abstract The improvement of environmental performance by gasoline direct injection (GDI) engine is remarkable. But the gas mixture formation process, which greatly affects the combustion of direct injection spark ignition (DISI) engines, still has a lot of areas left unclear. In this paper, a CFD model of air intake, fuel spray atomization and mixture formation process of a certain GDI engine was developed and experimentally verified for DISI injection study. The effects of injector spray layout and injection strategy on mixture quality of DISI engine were analyzed by respective simulation of three different injectors T1470, T1471, T1472. Results show that the mixture quality can be improved with appropriate injector spray orifices layout.
2015-04-14
Technical Paper
2015-01-0844
Sanghyun Chu, Jeongwoo Lee, Jaehyuk Cha, Hoimyung Choi, Kyoungdoug Min
Abstract The alternative fuel jet propellant 8 (JP-8, NATO F-34) can be used as an auto-ignition source instead of diesel. Because it has a higher volatility than diesel, it provides a better air-fuel premixing condition than a conventional diesel engine, which can be attributed to a reduction in particulate matter (PM). In homogeneous charged compression ignition (HCCI) or dual-fuel premixed charge compression ignition (PCCI) combustion or reactivity controlled compression ignition (RCCI), nitrogen oxides (NOx) can also be reduced by supplying external exhaust gas recirculation (EGR). In this research, the diesel and JP-8 injection strategies under conventional condition and dual-fuel PCCI combustion with and without external EGR was conducted. Two tests of dual-fuel (JP-8 and propane) PCCI were conducted at a low engine speed and load (1,500 rpm/IMEP 0.55 MPa).
2015-04-14
Technical Paper
2015-01-0843
Anand Nageswaran Bharath, Yangdongfang Yang, Rolf D. Reitz, Christopher Rutland
Abstract While Low Temperature Combustion (LTC) strategies such as Reactivity Controlled Compression Ignition (RCCI) exhibit high thermal efficiency and produce low NOx and soot emissions, low load operation is still a significant challenge due to high unburnt hydrocarbon (UHC) and carbon monoxide (CO) emissions, which occur as a result of poor combustion efficiencies at these operating points. Furthermore, the exhaust gas temperatures are insufficient to light-off the Diesel Oxidation Catalyst (DOC), thereby resulting in poor UHC and CO conversion efficiencies by the aftertreatment system. To achieve exhaust gas temperature values sufficient for DOC light-off, combustion can be appropriately phased by changing the ratio of gasoline to diesel in the cylinder, or by burning additional fuel injected during the expansion stroke through post-injection.
2015-04-14
Technical Paper
2015-01-1070
Hanzhengnan Yu, Yong Guo, Donghai Li, Xingyu Liang, Ge-Qun Shu, Yuesen Wang, Xiangxiang Wang, Lihui Dong
Abstract Impingement of injected fuel spray against the cylinder liner (wall wetting) is one of the main obstacles that must be overcome in order for early injection Homogeneous Charge Compression Ignition (EI HCCI) combustion. In the strategies to reduce or prevent wall wetting explored in the past, limiting the spray cone angle was proved to be a useful approach. This paper is presented to study the effect of the spray cone angle on the mixture formation, particularly the region near the cylinder wall (wall wetting region), and CO/Soot emissions of an EI HCCI diesel engine. Three-dimensional modeling was performed in AVL FIRE code. The calculation grid was divided into three regions which were defined as the combustion chamber region, the wall wetting region, and the central regions. The history of the CO/soot mass of each region and the equivalent ratio/temperature (φ-T map) of wall wetting region were analyzed.
2015-04-14
Technical Paper
2015-01-0745
Petter Dahlander, Stina Hemdal
Abstract To contribute to knowledge required to meet new emission requirements, relationships between multiple injection parameters, degrees of fuel stratification, combustion events, work output and flame luminosity (indicative of particulate abundance) were experimentally investigated using a single-cylinder optical GDI engine. A tested hypothesis was that advancing portions of the mass injected would enhance the fuel-air mixing and thus reduce flame luminescence. An outward-opening piezo actuated fuel injector capable of multiple injections was used to inject the fuel using different triple injection strategies, with various combinations of late and earlier injections leading to various degrees of fuel stratification. Sprays and combustion events were captured using two high-speed cameras and cylinder pressure measurements.
2015-04-14
Technical Paper
2015-01-0764
Seokwon Cho, Namho Kim, Jongwon Chung, Kyoungdoug Min
Abstract Ethanol is becoming more popular as a fuel component for spark-ignited engines. Ethanol can be used either as an octane enhancer of low RON gasoline or splash-blended with gasoline if a single injector is used for fuel injection. If two separate injectors are used, it is possible to inject gasoline and ethanol separately and the addition of ethanol can be varied on demand. In this study, the effect of the ethanol injection strategy on knock suppression was observed using a single cylinder engine equipped with two port fuel injectors dedicated to each side of the intake port and one direct injector. If the fuel is injected to only one side of the intake port, it is possible to form a stratified charge. The experiment was conducted under a compression ratio of 12.2 for various injection strategies.
2015-04-14
Technical Paper
2015-01-1647
Matthieu Lecompte, Stephane Raux, Jerome Cherel, Vivien Delpech
Abstract Euro VI standards for heavy duty vehicles require the use of a DPF in order to comply with the particulate matter emission limit. 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 soot mass trapped in the DPF increases. Some manufacturers made the choice of having 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 in-cylinder 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 the DOC and is 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
2015-01-0878
Guanzhang He, Hui Xie
Abstract The performance of three different electric turbo-compounding systems under both steady and driving cycle condition is investigated in this paper. Three configurations studied in this paper are serial turbo-compounding, parallel turbo-compounding and electric assisted turbo-compounding. The electric power, global gain of the whole system (engine and power turbine) under steady operating condition is firstly studied. Then investigation under three different driving cycles is conducted. Items including fuel consumption, engine operating point distribution and transient response performance are analyzed among which the second item is done based on statistic method combined with the results obtained under steady operating conditions. Study under steady condition indicates that electric assisted turbo-compounding system is the best choice compared with the other two systems.
2015-04-14
Technical Paper
2015-01-1264
Junseok Chang, Yoann Viollet, Abdullah Alzubail, Amir Faizal Naidu Abdul-Manan, Abdullah Al Arfaj
Abstract 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 the octane of the fuels based on real-time engine requirements. It is assumed that a vehicle was equipped with two fuel tanks and two injection systems; one port fuel injection and one direct injection line separately. Each tank carried low octane and high octane fuel so that real-time octane blending was occurred in the combustion chamber when needed (Octane On-Demand: OOD). A refinery naphtha was selected for low octane fuel (RON=61), because of its similarity to gasoline properties but a less processed, easier to produce without changing a refinery configuration. Three oxygenates were used for high octane knock-resistant fuels in a direct injection line: methanol, MTBE, and ETBE.
2015-04-14
Journal Article
2015-01-0893
Michael D. Kass, Chris Janke, Raynella Connatser, Sam Lewis, James Keiser, Timothy Theiss
Abstract The compatibility of plastic materials used in fuel storage and dispensing applications was determined for an off-highway diesel fuel and a blend containing 20% bio-oil (Bio20) derived from a fast pyrolysis process. Bio20 is not to be confused with B20, which is a diesel blend containing 20% biodiesel. The feedstock, processing, and chemistry of biodiesel are markedly different from bio-oil. Plastic materials included those identified for use as seals, coatings, piping and fiberglass resins, but many are also used in vehicle fueling systems. The plastic specimens were exposed to the two fuel types for 16 weeks at 60°C. After measuring the wetted volume and hardness, the specimens were dried for 65 hours at 60°C and then remeasured to determine extent of property change. A solubility analysis was performed to better understand the performance of plastic materials in fuel blends composed of bio-oil and diesel.
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
2015-01-0919
Timothy H. Lee, Yilu Lin, Han Wu, Lei Meng, Alan Hansen, Chia-Fon Lee
Abstract Recent research has shown that butanol, instead of ethanol, has the potential of introducing a more suitable blend in diesel engines. This is because butanol has properties similar to current transportation fuels in comparison to ethanol. However, the main downside is the high cost of the butanol production process. Acetone-butanol-ethanol (ABE) is an intermediate product of the fermentation process of butanol production. By eliminating the separation and purification processes, using ABE directly in diesel blends has the potential of greatly decreasing the overall cost for fuel production. This could lead to a vast commercial use of ABE-diesel blends on the market. Much research has been done in the past five years concerning spray and combustion processes of both neat ABE and ABE-diesel mixtures. Additionally, different compositions of ABE mixtures had been characterized with a similar experimental approach.
2015-04-14
Technical Paper
2015-01-0911
Juliane Wetzel, Michael Henn, Mark Gotthardt, Hermann Rottengruber
Abstract The optimization of the mixture formation represents great potential to decrease fuel consumption and emissions of spark-ignition engines. The injector and the nozzle are of major importance in this concern. In order to adjust the nozzle geometry according to the requirements an understanding of the physical transactions in the fuel spray is essential. In particular, the primary spray break-up is still described inadequately due to the difficult accessibility with optical measuring instruments. This paper presents a methodology for the characterization of the nozzle-near spray development, which substantially influences the entire spray shape. Single hole injectors of the gasoline direct injection (GDI) with different nozzle hole geometries have been investigated in a high pressure chamber by using the MIE scattering technique. To examine the spray very close to the nozzle exit a long-distance microscope in combination with a Nd:YAG-laser was used.
2015-04-14
Technical Paper
2015-01-0914
Ehsan Tootoonchi, Gerald Micklow
Abstract Understanding the physics and chemistry involved in diesel combustion, with its transient effects and the inhomogeneity of spray combustion is quite challenging. Great insight into the physics of the problem can be obtained when an in-cylinder computational analysis is used in conjunction with either an experimental program or through published experimental data. The main area to be investigated to obtain good combustion begins with the fuel injection process and the mean diameter of the fuel particle, injection pressure, drag coefficient, rate shaping etc. must be defined correctly. The increased NOx production and reduced power output found in engines running biodiesel in comparison to petrodiesel is believed to be related to the different fuel characteristics in comparison to petroleum based diesel. The fuel spray for biodiesel penetrates farther into the cylinder with a smaller cone angle. Also the fuel properties between biodiesel and petrodiesel are markedly different.
2015-04-14
Technical Paper
2015-01-0913
Ryo Uchida, Daisuke Tanaka, Toru Noda, Shinya Okamoto, Keiji Ozawa, Tsuneaki Ishima
Abstract 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
2015-01-0925
Erik Elmtoft, A. S. (Ed) Cheng, Nick Killingsworth, Russell Whitesides
Abstract Injection spray dynamics is known to be of great importance when modeling turbulent multi-phase flows in diesel 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 liquid n-heptane is characterized with initial droplet sizes with diameters on the order of 0.10 - 0.25 nozzle diameters. This is done for a Reynolds Averaged Navier-Stokes (RANS) RNG k-ε turbulence model with a minimum grid size of 125 μm and for a Large Eddy Simulations (LES) viscosity turbulence model with a minimum grid size of 62.5 μm. The results of both turbulence models are validated against non-reacting experimental data from the Engine Combustion Network (ECN). The results show that the injected droplet sizes have a significant impact on both liquid and vapor penetration lengths.
Viewing 1 to 30 of 5837