Criteria

Text:
Display:

Results

Viewing 1 to 30 of 323
2016-04-05
Technical Paper
2016-01-1284
Andrew Burnham, Hao Cai, Michael Wang
A heavy-duty vehicle (HDV) module of the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model has been developed at Argonne National Laboratory. In the past, the life-cycle GREET model has been published extensively and contains data on fuel-cycles and vehicle operation of light-duty vehicles. The addition of the HDV module to the GREET model allows for well-to-wheels (WTW) analyses of advanced technology and alternative fuel heavy-duty vehicles, which has been scarce in the literature. WTW analyses of HDVs becomes increasingly important to understand the impacts of newly enacted and future greenhouse gas (GHG) emission and fuel consumption regulations from the Environmental Protection Agency and the Department of Transportation’s National Highway Traffic Safety Administration on these vehicle types.
2016-04-05
Technical Paper
2016-01-0585
Muhsin M. Ameen, Yuanjiang Pei, Sibendu Som
The primary strength of large eddy simulation (LES) is in directly resolving the instantaneous large-scale flow features which can then be used to study critical flame properties such as ignition, extinction, flame propagation and lift-off. However, validation of the LES results with experimental or direct numerical simulation (DNS) datasets requires the determination of statistically-averaged quantities. This is typically done by performing multiple realizations of LES and performing a statistical averaging among this sample. In this study, LES of n-dodecane spray flame is performed using a detailed combustion model along with a dynamic structure subgrid model. A high-resolution mesh is employed with a cell size of 0.0625 mm in the entire spray and combustion regions. In the first part of this study, two methods of perturbing the LES solutions is examined. The first method consists of changing a random seed which is used in the spray breakup and vaporization models.
2016-04-05
Technical Paper
2016-01-0602
Janardhan Kodavasal, Yuanjiang Pei, Kevin Harms, Stephen Ciatti, Al Wagner, Peter Senecal, Marta García, Sibendu Som
In internal combustion engine computational fluid dynamics (CFD) simulations, uncertainties arise from various sources, such as estimates of model parameters, experimental boundary conditions, estimates of chemical kinetic rates, etc. These uncertainties propagate through the model and result in discrepancies compared to experimental measurements. The relative importance of the various sources of uncertainty can be quantified by performing a sensitivity analysis. In this work, global sensitivity analysis (GSA) was applied to Gasoline Compression Ignition engine simulations to understand the influence of uncertainties from various sources on specific targets of interest—ignition timing, combustion phasing, and emissions. The sensitivity of these targets was evaluated with respect to imposed uncertainties in experimental boundary conditions. In the present study, the sensitivity of the targets to uncertainties in CFD model parameters and chemical kinetic rates was not studied.
2016-04-05
Technical Paper
2016-01-0903
Ram Vijayagopal, Kevin Gallagher, Daeheung Lee, Aymeric Rousseau
The energy density and power density comparisons of conventional fuels and batteries is often taken as an indicator for the comparison of conventional vehicles and electric vehicles. Such an analysis often shows that the batteries are a few order of magnitudes behind fuels like gasoline. However this analysis ignores the impact of powertrain efficiency. When we compare the potential of battery electric vehicles (BEVs) as an alternative for conventional vehicles, it is important to include the energy in the fuel and their storage as well as the eventual conversion to mechanical energy. For comparison purposes we can expect the useful work expected out of a conventional vehicle as well as a BEV is the same, i.e. to drive 300 miles with the payload of about 300 lbs. Both Conventional and BEV will have a much different test weight based on what is needed to convert their respective stored energy to mechanical energy.
2016-04-05
Technical Paper
2016-01-1213
Ram Vijayagopal, Kevin Gallagher, Daeheung Lee, Aymeric Rousseau
The current battery technologies allow an EV with 300 mile range (BEV 300), but the cost of such a vehicle hinders the large scale adoption of this vehicle by consumers. DOE has set aggressive cost targets for battery technologies. At present, no single technology might meet the cost, energy and power requirements of a BEV 300, but a combination of multiple batteries with different capabilities might meet this criteria. This study looks at how such a combination can be implemented in the vehicle simulation model and compares the vehicle manufacturing cost and operating costs of these options. Preliminary analysis shows that there is an opportunity to modestly reduce BEV 300 energy storage system cost, by about 8%, using a battery pack combining an energy battery and a power battery. The baseline vehicle considered in the study uses a single battery sized to meet both power and energy requirements in a BEV 300.
2016-04-05
Technical Paper
2016-01-0794
Reed Hanson, Andrew Ickes, Thomas Wallner
Dual-fuel combustion using port-injection of low reactivity fuel combined with direct injection of a higher reactivity fuel, otherwise known as Reactivity Controlled Compression Ignition (RCCI), has been shown as a method to achieve low-temperature combustion with moderate peak pressure rise rates, low engine-out soot and NOx emissions, and high indicated thermal efficiency. A key requirement for extending to high-load operation is moderating the reactivity of the premixed charge prior to the diesel injection. One way to accomplish this is to use a very low reactivity fuel such as natural gas. In this work, experimental testing was conducted on a 13L multi-cylinder heavy-duty diesel engine modified to operate using RCCI combustion with port injection of natural gas and direct injection of diesel fuel. Natural gas/diesel RCCI engine operation is compared over the EPA Heavy-Duty 13 mode supplemental emissions test with and without EGR.
2016-04-05
Technical Paper
2016-01-1194
Panos D. Prezas, L. Somerville, P Jennings, A McGordon, J. K. Basco, T. Duong, I. Bloom
As electrified vehicles become more common in the market place, consumers would expect to have similar experiences as cars powered by an internal-combustion engine. This is especially true when it comes to “refueling” the vehicle. Refueling an internal combustion vehicle takes up to 10-15 min. On the other hand, fully charging a lithium-ion battery system can take 1-2 h. To meet the expectations set by the internal combustion engine, the battery system would have to be charged at the 4-to-6-C rate. Additionally, if a motorist runs out of gasoline on the highway, 20 L of fuel can be quickly added to the tank, partially refilling the tank and enabling the motorist to get to his next destination. The results of our investigation on the effects of fast-charging commercially-available lithium-ion cells on performance, life and physical condition of the electrodes in the cells in both scenarios, full and partial charging, will be presented.
2016-04-05
Technical Paper
2016-01-0609
Anqi Zhang, Riccardo Scarcelli, Seong-Young Lee, Thomas Wallner, Jeffrey Naber
It is beneficial but challenging to operate spark-ignition engines under highly lean and dilute conditions. The unstable ignition behavior can result in downgraded combustion performance in engine cylinders. Numerical approach is serving as a promising tool to identify the ignition requirements by providing insights into the complex physical/chemical phenomena. An effort to simulate the early stage of flame kernel initiation in lean and dilute fuel/air mixture has been made and discussed in this paper. The simulations are set to validate against laboratory results of spark ignition behavior in a constant volume combustion vessel. In order to present a practical as well as comprehensive ignition model, the simulations are performed by taking into consideration the discharge circuit analysis, the detailed reaction mechanism, and local heat transfer between the flame kernel and spark plug.
2016-04-05
Technical Paper
2016-01-1151
Jongryeol JEONG, Dominik Karbowski, Aymeric Rousseau, Eric Rask
This paper presents the validation of an entire vehicle model of the Honda Accord Plug-in Hybrid Electric Vehicle (PHEV), including thermal aspects. The Honda Accord Plug-in is a series-parallel PHEV with about 21 km of all electric range, and no multi-speed gearbox. Testing of the vehicle was performed at Argonne’s Advanced Powertrain Research Facility, on a chassis dynamometer set in a thermal chamber. First, components (engine, battery, etc.) are modeled using test data and publicly available assumptions. This also includes calibration of the thermal aspects, such as engine efficiency as a function of coolant temperature, or thermal capacity of the engine. In a second phase, the control strategy of the vehicle in normal conditions, especially the energy management, is analyzed, both in charge-depleting and charge-sustaining mode.
2016-04-05
Technical Paper
2016-01-0593
Riccardo Scarcelli, Keith Richards, Eric Pomraning, P. K. Senecal, Thomas Wallner, James Sevik
Reynolds-averaged Navier-Stokes (RANS) modeling is expected to deliver an ensemble-averaged result for the majority of turbulent flows. This could lead to the conclusion that multi-cycle internal combustion engine (ICE) simulations performed using RANS must exhibit a converging numerical solution after a certain number of consecutive cycles. For some engine configurations, unsteady RANS simulations are not guaranteed to deliver an ensemble-averaged result. In this paper it is shown that, when using RANS modeling to simulate multiple engine cycles, the cycle-to-cycle variations (CCV) coming from different initial conditions at each cycle are not damped out even after a large number of cycles. A single-cylinder GDI research engine is simulated using RANS modeling and the numerical results for 20 consecutive engine cycles are evaluated for two specific operating conditions.
2016-04-05
Technical Paper
2016-01-0152
Pierre Michel, Dominik Karbowski, Aymeric Rousseau
Connectivity and automation are increasingly being developed for cars and trucks, aiming to provide better safety and better driving experience. As these technology mature and reach higher adoption rates, they will also have an impact on the energy consumption: connected and automated vehicles (CAVs) may drive more smoothly, stop less and move at faster speeds, thanks to overall improvements to traffic flows. These potential impacts are not well studied and their study tend to focus solely on conventional engine-powered cars, leaving on the side electrified vehicles such as hybrid electric vehicles (HEVs) and battery electric vehicles (BEVs). This work intends to address this issue by analyzing the energy impact of various CAV scenarios on different types of electric vehicles using high-fidelity models. The vehicles, all midsize, one HEV, one BEV and a conventional are modeled in Autonomie, a high-fidelity forward-looking vehicle simulation tool.
2016-04-05
Technical Paper
2016-01-1180
Trevor Crain, Thomas Gorgia, R. Jesse Alley
EcoCAR is North America's premier collegiate automotive engineering competition, challenging students with systems-level advanced powertrain design and integration. The EcoCAR Advanced Vehicle Technology Competition series is organized by Argonne National Laboratory, headline sponsored by the U. S. Department of Energy and General Motors, and sponsored by more than 30 industry and government leaders. In the last competition series, EcoCAR 2, fifteen university teams from across North America were challenged to reduce the environmental impact of a 2013 Chevrolet Malibu by redesigning the vehicle powertrain without compromising performance, safety, or consumer acceptability. This paper examines the results of the EcoCAR 2 competition's emissions and energy consumption (E&EC) on-road test results for several prototype plug-in hybrid electric vehicles (PHEVs). The official results for each vehicle are presented along with brief descriptions of the hybrid architectures.
2016-04-05
Journal Article
2016-01-0901
Richard Barney Carlson, Jeffrey Wishart, Kevin Stutenberg
Laboratory and on-road vehicle evaluation is conducted on four vehicle models to evaluate and characterize the real-world auxiliary loads over a wide range of conditions. The four vehicle models in this study include the Volkswagen Jetta TDI, Mazda 3 i-ELOOP, Chevrolet Cruze Diesel, and Honda Civic GX (CNG). Evaluation was conducted using a chassis dynamometer over standardized drive cycles as well as 12 months of on-road driving across a wide range of road and environmental conditions. The information gathered in the study serves as a baseline to quantify future improvements in auxiliary load reduction technology. The results from this study directly support automotive manufacturers in regards to potential “off-cycle” fuel economy credits as part of the Corporate Average Fuel Economy (CAFE) regulations, in which credit is provided for advanced technologies in which reduction of energy consumption from vehicle auxiliary loads can be demonstrated.
2016-04-05
Journal Article
2016-01-0776
Mateos Kassa, Carrie Hall, Andrew Ickes, Thomas Wallner
Advanced internal combustion engines, although generally more efficient than conventional combustion engines, often encounter limitations in multi-cylinder applications due to cylinder-to-cylinder variations in the combustion process. This study leverages experimental data from an inline 6-cylinder heavy-duty dual fuel engine equipped with a fully-flexible variable intake valve actuation system to study cylinder-to-cylinder variations in power production. The engine is operated with late intake valve closure timings in a dual-fuel combustion mode featuring a port-injection and a direct-injection fueling system. Both dual fuel implementation and late intake valve closing (IVC) timings have been shown to improve thermal efficiency. However, experimental data from this study reveal that when late IVC timings are used on a multi-cylinder dual fuel engine a significant variation in power production across cylinders results and as such, leads to efficiency losses.
2016-04-05
Journal Article
2016-01-0640
Alan Kastengren, Daniel Duke, Andrew Swantek, James Sevik, Katarzyna Matusik, Thomas Wallner, Christopher F. Powell
Understanding the short-lived structure of the plasma that forms between the electrodes of a spark plug is crucial to the development of improved ignition models for SI engines. However, measuring the amount of energy deposited in the gas directly and non-intrusively is difficult, due to the short time scales and small length scales involved. The breakdown of the spark gap occurs at nanosecond time scales, followed by an arc phase lasting a few microseconds. Finally, a glow discharge phase occurs over several milliseconds. It is during the arc and glow discharge phases that most of the heat transfer from the plasma to the electrodes and combustion gases occurs. In this paper, we present the results of a proof of concept experiment that demonstrates the use of time-resolved x-ray radiography to measure the density of the plasma in the spark gap during the glow discharge phase of a conventional transistorized coil ignition system.
2016-04-05
Journal Article
2016-01-0734
Scott A. Skeen, Julien Manin, Lyle M. Pickett, Emre Cenker, Gilles Bruneaux, Katsufumi Kondo, Tets Aizawa, Fredrik Westlye, Kristine Dalen, Anders Ivarsson, Tiemin Xuan, Jose M Garcia-Oliver, Yuanjiang Pei, Sibendu Som, Wang Hu, Rolf D. Reitz, Tommaso Lucchini, Gianluca D'Errico, Daniele Farrace, Sushant S. Pandurangi, Yuri M. Wright, Muhammad Aqib Chishty, Michele Bolla, Evatt Hawkes
The 4th Workshop of the Engine Combustion Network (ECN) was held September 5-6, 2015 in Kyoto, Japan. This manuscript presents a summary of the progress in experiments and modeling among ECN contributors leading to a better understanding of soot formation under the ECN “Spray A” configuration and some parametric variants. Relevant published and unpublished work from prior ECN workshops is reviewed. Experiments measuring soot particle size and morphology, soot volume fraction (fv), and transient soot mass have been conducted at various international institutions providing target data for improvements to computational models. Multiple modeling contributions using both the Reynolds Averaged Navier-Stokes (RANS) Equations approach and the Large-Eddy Simulation (LES) approach have been submitted. Among these, various chemical mechanisms, soot models, and turbulence-chemistry interaction (TCI) methodologies have been considered.
2016-04-05
Technical Paper
2016-01-0314
Larry Michaels, Curtis G. Adams, Michael Juskiewicz
A simulation approach is defined that integrates a military mission assessment tool (OneSAF) to a commercial automotive control/energy consumption development tool (Autonomie). The objective is to enable vehicle energy utilization and fuel consumption impact assessments relative to US Army mission effectiveness and commercial drive cycles. The approach to this integration will be described along with its potential to meet its objectives.
2016-04-05
Journal Article
2016-01-0236
Forrest Jehlik, Eric Rask, Michael Duoba
It is widely understood that cold ambient temperatures negatively impact vehicle system efficiency. This is due to a combination of increased friction (engine oil, transmission, and driveline viscous effects), cold start enrichment, heat transfer, and air density variations. Although the art of quantifying steady state vehicle component efficiency is well understood, transient component efficiencies over dynamic ambient real world conditions is less well understood and quantified. This work characterizes wheel assembly efficiencies of a conventional and electric vehicle over a wide range of ambient conditions. Dynamometer testing over three ambient temperatures and drive cycles was conducted with vehicles instrumented to determine the losses of the output energy of the tire on the dynamometer proportional to the input energy of the half-shafts.
2016-04-05
Journal Article
2016-01-0857
Muhammad Aqib Chishty, Michele Bolla, Evatt Hawkes, Yuanjiang Pei, Sanghoon Kook
The importance of radiative heat transfer on the combustion and soot formation characteristics under nominal ECN Spray A conditions has been studied numerically. The liquid n-dodecane fuel is injected with 1500 bar fuel pressure into the constant volume chamber at different ambient conditions. Radiation from both gas-phase as well as soot particles has been included and assumed as gray. Three different solvers for the radiative transfer equation have been employed: the discrete ordinate method, the spherical-harmonics method and the optically thin assumption. The radiation models have been coupled with the transported probability density function method for turbulent reactive flows and soot, where unresolved turbulent fluctuations in temperature and composition are included and therefore capturing turbulence-chemistry-soot-radiation interactions. Results show that the gas-phase (mostly CO2 ad H2O species) has a higher contribution to the net radiation heat transfer compared to soot.
2016-04-05
Technical Paper
2016-01-0858
Piotr Strek, Daniel Duke, Andrew Swantek, Alan Kastengren, Christopher F. Powell, David P. Schmidt
The salient features of modern gasoline direct injection include cavitation, flash boiling, and plume/plume interaction, depending on the operating conditions. These complex phenomena make the prediction of the spray behavior particularly difficult to understand and predict. The present investigation combines mass-based experimental diagnostics with an advanced, in-house modeling capability in order to provide a multi-faceted study of the Engine Combustion Network's Spray G injector. First, radiography is used to distinguish the actual injector geometry from the nominal geometry used in past works. The actual geometry is used as the basis of multidimensional CFD simulations which are compared to measurements for validation under cold conditions. The influence of nozzle diameter and corner radius are of particular interest. Next, the model is used to simulate flash-boiling conditions, in order to understand how the cold flow behavior corresponds to flashing performance.
2016-04-05
Technical Paper
2016-01-0870
Kaushik Saha, Sibendu Som, Michele Battistoni, Yanheng Li, Eric Pomraning, P. K. Senecal
The present work involves modeling of internal and near-nozzle flows of a Gasoline Direct Injection (GDI) nozzle. The ECN Spray G conditions have been considered for these simulations using the nominal geometry of the Spray G injector. Initially best practices for numerical simulation of the two-phase flow evolution inside and the near-nozzle regions of the Spray G injector are presented for the peak needle lift. Mass flow rate prediction for peak needle lift was in reasonable agreement with experimental data available in the ECN database. Capability of assessing the influence of different thermodynamic conditions on the two-phase flow nature have been established, by predicting non-flashing, moderate flashing and intense flashing and correlating with degree of superheat and non-dimensional numbers such as, Jakob number.
2016-04-05
Journal Article
2016-01-0806
James Sevik, Michael Pamminger, Thomas Wallner, Riccardo Scarcelli, Ronald Reese, Asim Iqbal, Brad Boyer, Steven Wooldridge, Carrie Hall, Scott Miers
In recent times, interest in natural gas as a fuel for light-duty transportation has increased due to its domestic availability and lower cost relative to gasoline. Natural gas, comprised mainly of methane, has a higher knock resistance than gasoline making it advantageous for high load operation. However, the higher resistance to knock can cause ignitability issues at part-load operation leading to an increase in the initial flame development process. Part-load exhaust gas recirculation tolerance can also be affected by the lower flame speed of natural gas. While port-fuel injection of natural gas can lead to a loss in power density due to the displacement of intake air, injecting natural gas directly into the cylinder can reduce such losses. A study was designed and performed to evaluate the potential of natural gas for use as a light-duty fuel.
2016-04-05
Technical Paper
2016-01-0850
Lorenzo Bartolucci, Riccardo Scarcelli, Thomas Wallner, Andrew Swantek, Christopher F. Powell, Alan Kastengren, Daniel Duke
Blending natural gas with gasoline in an internal combustion engines is emerging as a promising way to improve thermal efficiency and reduce exhaust emissions. In the development of such engine platforms, computational fluid dynamics (CFD) plays a fundamental role in the optimization of geometries and operating parameters. One of the most relevant issues in the simulation of direct injection (DI) processes is the prediction accuracy of the gas jet evolution. The simulation of the injection process for a gaseous fuel does not require complex modeling itself, nevertheless describing high-pressure gas jets remains a challenging task. At the exit of the nozzle, the gas is under-expanded, the flow becomes supersonic and shocks occur due to compressibility effects. These phenomena lead to high computational requirements resulting from a high grid resolution and computational time-steps. Timely simulations of gaseous injection thus, become challenging.
2015-10-12
Article
Recognizing the power of technologies such as energy storage and nanotechnology and seeking ways to accelerate their impact, Argonne has created two new collaborative centers that it is hoping will provide an innovative pathway for business and industry to speed discoveries to market.
2015-09-29
Technical Paper
2015-01-2895
Prasad Vegendla, Tanju Sofu, Rohit Saha, Mahesh Madurai Kumar, Long-Kung Hwang
Abstract This paper investigates the aerodynamic influence of multiple on-highway trucks in different platooning configurations. Complex pressure fields are generated on the highways due to interference of multiple vehicles. This pressure field causes an aerodynamic drag to be different than the aerodynamic drag of a vehicle in a no-traffic condition. In order to study the effect of platooning, three-dimensional modeling and numerical simulations were performed using STAR-CCM+® commercial Computational Fluid Dynamics (CFD) tool. The aerodynamic characteristics of vehicles were analyzed in five different platooning configurations with two and three vehicles in single and multiple lanes. A significant Yaw Averaged Aerodynamic Drag (YAD) reduction was observed in both leading and trailing vehicles. YAD was based on the average result of three different yaw angles at 0°, −6° and 6°. In single-lane traffic, YAD reduction was up to 8% and 38% in leading and trailing vehicles, respectively.
2015-09-06
Technical Paper
2015-24-2390
Shashi Aithal, Stefan Wild
Abstract Design and optimization of automotive engines present unique challenges on account of the large design space and conflicting constraints. A notable example of such a problem is optimizing the fuel consumption and reducing emissions over the drive cycle of an automotive engine. There are over twenty design variables (including operating conditions and geometry) for the above-mentioned problem. Conducting design, analyses, and optimization studies over such a large parametric space presents a serious computational challenge. The large design parameter space precludes the use of detailed numerical or experimental investigations. Physics-based reduced-order models can be used effectively in the design and optimization of such problems.
2015-09-01
Technical Paper
2015-01-1796
Andrew Ickes, Reed Hanson, Thomas Wallner
Dual-fuel combustion using port-injected gasoline with a direct diesel injection has been shown to achieve low-temperature combustion with moderate peak pressure rise rates, low engine-out soot and NOx emissions, and high indicated thermal efficiency. A key requirement for extending high-load operation is moderating the reactivity of the premixed charge prior to the diesel injection. Reducing compression ratio, in conjunction with a higher expansion ratio using alternative valve timings, decreases compressed charge reactivity while maintain a high expansion ratio for maximum work extraction. Experimental testing was conducted on a 13L multi-cylinder heavy-duty diesel engine modified to operate dual-fuel combustion with port gasoline injection to supplement the direct diesel injection. The engine employs intake variable valve actuation (VVA) for early (EIVC) or late (LIVC) intake valve closing to yield reduced effective compression ratio.
2015-09-01
Technical Paper
2015-01-1834
Andrew. B Swantek, Daniel J. Duke, Christopher F. Powell, Alan L. Kastengren
Recent advances in x-ray spray diagnostics at Argonne National Laboratory's Advanced Photon Source have made absorption measurements of individual spray events possible. A focused x-ray beam (5×6 μm) enables collection of data along a single line of sight in the flow field and these measurements have allowed the calculation of quantitative, shot-to-shot statistics for the projected mass of fuel sprays. Raster scanning though the spray generates a two-dimensional field of data, which is a path integrated representation of a three-dimensional flow. In a previous work, we investigated the shot-to-shot variation over 32 events by visualizing the ensemble standard deviations throughout a two dimensional mapping of the spray. In the current work, provide further analysis of the time to steady-state and steady-state spatial location of the fluctuating field via the transverse integrated fluctuations (TIF).
2015-09-01
Technical Paper
2015-01-1844
Yuanjiang Pei, Sibendu Som, Prithwish Kundu, Graham M. Goldin
Reynolds-averaged Navier-Stokes (RANS) turbulence model has been used extensively for diesel engine simulations due to its computational efficiency and is expected to remain the workhorse computational fluid dynamics (CFD) tool for industry in the near future. Alternatively, large eddy simulations (LES) can potentially deal with complex flows and cover a large disparity of turbulence length scales, which makes this technique more and more attractive in the engine community. An n-dodecane spray flame (Spray A from Engine Combustion Network) was simulated using a dynamic structure LES model to understand the transient behavior of this turbulent flame. The liquid spray was treated with a traditional Lagrangian method and the gas-phase reaction was closed using a delta probability density function (PDF) combustion model. A 103-species skeletal mechanism was used for n-dodecane chemical kinetic model.
2015-09-01
Technical Paper
2015-01-1849
Muhammad Aqib Chishty, Michele Bolla, Yuanjiang Pei, Evatt R. Hawkes, Sanghoon Kook, Tianfeng Lu
Numerical simulations of soot formation were performed for n-dodecane spray using the transported probability density function (TPDF) method. Liquid n-dodecane was injected with 1500 bar fuel pressure into a constant-volume vessel with an ambient temperature, oxygen volume fraction and density of 900 K, 15% and 22.8 kg/m3, respectively. The interaction by exchange with the mean (IEM) model was employed to close the micro-mixing term. The unsteady Reynolds-averaged Navier-Stokes (RANS) equations coupled with the realizable k-ε turbulence model were used to provide turbulence information to the TPDF solver. A 53-species reduced n-dodecane chemical mechanism was employed to evaluate the reaction rates. Soot formation was modelled with an acetylene-based two-equation model which accounts for simultaneous soot particle inception, surface growth, coagulation and oxidation by O2 and OH.
Viewing 1 to 30 of 323

Filter

  • Range:
    to:
  • Year: