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Viewing 1 to 30 of 20059
2010-10-25
Technical Paper
2010-01-2214
Xianjing Li, Liguang Li, Yongzheng Sun, Zongjie Hu, Jun Deng
Plug-in hybrid electric vehicles (PHEVs) provide significantly improvement in fuel economy over conventional vehicles as well as reductions in greenhouse gas and petroleum. Numerous recent reports regarding control strategy, power train configuration, driving pattern, all electric range (AER) and their effects on fuel consumption and electric energy consumption of PHEVs are reported. Meanwhile, the control strategy for engine start-stop and mileage between recharging events from the electricity grid also has an important influence on the petroleum displacement potential of PHEVs, but few reports are published. In this paper, a detailed simulation model is set up for a plug-in series hybrid electric vehicle (PSHEV) employing the AVL CRUISE. The model was employed to predict the AER of the baseline PSHEV using rule-based logical threshold switching control strategy.
2010-09-28
Technical Paper
2010-32-0041
Jih Houh Lee, Horizon Gitano, Hock Seng Eu, Ahmad Syazli Mohd Khalil
Existing drive cycles do not correlate well with actual drive cycles in developing countries due to differences in vehicle mixes, and traffic flow patterns. Several distinct drive cycles were identified in Malaysia namely the urban, suburban, rural, highway and delivery drive cycles. Several methods were used in generating drive cycles including direct observation, motorcyclist surveys, vehicle shadowing with on-board wheel speed measurement and data logging. These drive cycles were compared to existing European, United States, world harmonized motorcycle drive cycles and evaluated for fuel consumption. Results indicate that the Malaysian drive cycles are capable predicting actual vehicle fuel mileage within +/− 10% for a wide range of vehicles, while the European drive cycle results in a 20%deviation from the actual vehicle fuel mileage.
2010-09-28
Technical Paper
2010-32-0078
Taib Iskandar Mohamad, Ali Yusoff, Shahrir Abdullah, Mark Jermy, Matthew Harrison, How Heoy Geok
Compressed natural gas (CNG) has been widely used as alternatives to gasoline and diesel in automotive engines. It is a very promising alternative fuel due to many reasons including adaptability to those engines, low in cost, and low emission levels. Unfortunately, when converting to CNG, engines usually suffer from reduced power and limited engine speed. These are due to volumetric loss and slower flame speed. Direct injection (DI) can mitigate these problems by injecting CNG after the intake valve closes, thus increasing volumetric efficiency. In addition, the high pressure gas jet can enhance the turbulence in the cylinder which is beneficial to the mixing and burning. However, conversion to direct fuel injection (DFI) requires a costly modification to the cylinder head to accommodate the direct injector and also can involve piston crown adjustment. This paper discusses a new alternative to converting to DFI using a device called Spark Plug Fuel Injector (SPFI).
2010-09-28
Technical Paper
2010-32-0069
Gustavo Fontana, Fabio Bozza, Enzo Galloni, Daniela Siano
In this paper, an experimental and numerical analysis of combustion process and knock occurrence in a small displacement spark-ignition engine is presented. A wide experimental campaign is preliminarily carried out in order to fully characterize the engine behavior in different operating conditions. In particular, the acquisition of a large number of consecutive pressure cycle is realized to analyze the Cyclic Variability (CV) effects in terms of Indicated Mean Effective Pressure (IMEP) Coefficient of Variation (CoV). The spark advance is also changed up to incipient knocking conditions, basing on a proper definition of a knock index. The latter is estimated through the decomposition and the FFT analysis of the instantaneous pressure cycles. Contemporary, a quasi-dimensional combustion and knock model, included within a whole engine one-dimensional (1D) modeling framework, are developed. Combustion and knock models are extended to include the CV effects, too.
2010-10-19
Technical Paper
2010-01-2335
Jeffrey D. Rupp, Anthony G. King
Successful demonstrations of fully autonomous vehicle operation in controlled situations are leading to increased research investment and activity. This has already resulted in significant advancements in the underlying technologies necessary to make it a practical reality someday. Not only are these idealized events sparking imaginations with the potential benefits for safety, convenience, fuel economy and emissions, they also embolden some to make somewhat surprising and sometimes astonishing projections for their appearance on public roads in the near future. Are we now ready for a giant leap forward to the self-driving car with all its complexity and inter-dependencies? Humans will need to grow with and adapt to the technological advancements of the machine and we'll deeply challenge our social and political paradigms before we're done. Even if we as engineers are ready, is the driving public ready?
2010-10-05
Technical Paper
2010-01-2041
Bernard J. Simon
The transition towards a ‘Green Economy’ puts pressure on automakers to improve the fuel economy of their vehicles. Fuel economy is complicated vehicle attribute impacted by a large number of factors, not limited to vehicle weight, rolling resistance, aerodynamic drag, engine efficiency, drive train losses, accessory loading, and performance targets embodied in the controls strategy. Due to the number and complexity of contributing factors, fuel economy benchmarking, target setting and technology evaluation can be difficult. This paper introduces two new vehicle attributes: miles per kilowatt-hour (mpk) and kilowatt-hours per gallon (kpg) which, when multiplied together, calculate mpg. These parameters are derived from emissions and fuel economy certification data posted by the EPA on their website. This paper then shows how these parameters can be used to characterize and benchmark vehicles, set targets for new vehicles, and project future technology trends.
2010-10-25
Technical Paper
2010-01-2151
Atsushi Matsumoto, Yi Zheng, Xing-Bin Xie, Ming-Chia Lai, Wayne Moore
Because of their robustness and cost performance, multi-hole gasoline injectors are being adopted as the direct injection (DI) fuel injector of choice as vehicle manufacturers look for ways to reduce fuel consumption without sacrificing power and emission performance. To realize the full benefits of direct injection, the resulting spray needs to be well targeted, atomized, and appropriately mixed with charge air for the desirable fuel vapor concentration distributions in the combustion chamber. Ethanol and ethanol-gasoline blends synergistically improve the turbo-charged DI gasoline performance, especially in down-sized, down-sped and variable-valve-train engine architecture. This paper presents the spray imaging results from two multi-hole DI gasoline injectors with different design, fueled with pure ethanol (E100) or gasoline (E0), under homogeneous and stratified-charge conditions that represent typical engine operating points.
2010-10-05
Technical Paper
2010-01-2033
Gergis W. William
Currently, the chassis assembly contributes about 73 percent of the overall weight of a 14.63 m long haul trailer. This paper presents alternative design concepts for the structural floor of a van trailer utilizing sandwich panels with various material and geometric characteristics of the core layer in order to reduce its weight significantly below that of the current design configuration. The main objective of the new designs is to achieve optimal tradeoffs between the overall structural weight and the flexural stiffness of the floor. Various preliminary design concepts of the core designs were compared on the basis of a single section of the core structure. Six different designs were analyzed by weight, maximum displacement and maximum stress under bending and torsion loads. Each concept was kept uniform by length, thickness, loading and boundary conditions. Each design concept was examined through testing of scaled model for floor assemblies.
2010-10-05
Technical Paper
2010-01-2039
Stargel Doane, Drew Landman, Richard M. Wood
A computer simulation was developed to investigate the effect of wind on test track estimation of heavy truck fuel efficiency. Monte Carlo simulations were run for various wind conditions, both with and without gusts, and for two different vehicle aerodynamic configurations. The vehicle configurations chosen for this study are representative of typical Class 8 tractor trailers and use wind tunnel measured drag polars for performance computations. The baseline (control) case is representative of a modern streamlined tractor and conventional trailer. The comparison (test) case is the baseline case with the addition of a trailer drag reduction device (trailer skirt). The integrated drag coefficient, overall required power, total fuel consumption, and average rate of fuel consumption were calculated for a heavy truck on an oval test track to show the effect of wind on test results.
2010-10-05
Technical Paper
2010-01-2040
Mathew Heinecke, Jeremy Beedy, Kevin Horrigan, Raja Sengupta
The importance of fuel economy and emission standards has increased rapidly with high fuel costs and new environmental regulations. This requires analysis techniques capable of designing the next generation long-haul truck to improve both fuel efficiency and cooling. In particular, it is important to have a predictive design tool to assess how exterior design changes impact aerodynamic performance. This study evaluates the use of a Lattice Boltzmann based numerical simulation and the National Research Council (NRC) Canada's wind tunnel to assess aerodynamic drag on a production Volvo VNL tractor-trailer combination. Comparisons are made between the wind tunnel and simulation to understand the influence of wind tunnel conditions on truck aerodynamic performance. The production VNL testing includes a full range of yaw angles to demonstrate the influence of cross wind on aerodynamic drag.
2010-10-25
Technical Paper
2010-01-2238
Yongli Qi, Hao Liu, Kenneth Midkiff, Paulius Puzinauskas
Today's engine and combustion process development is closely related to the intake port layout. Combustion, performance and emissions are coupled to the intensity of turbulence, the quality of mixture formation and the distribution of residual gas, all of which depend on the in-cylinder charge motion, which is mainly determined by the intake port and cylinder head design. Additionally, an increasing level of volumetric efficiency is demanded for a high power output. Most optimization efforts on typical homogeneous charge spark ignition (HCSI) engines have been at low loads because that is all that is required for a vehicle to make it through the FTP cycle. However, due to pumping losses, this is where such engines are least efficient, so it would be good to find strategies to allow the engine to operate at higher loads.
2010-10-25
Technical Paper
2010-01-2239
Yongli Qi, Hao Liu, Kenneth Midkiff, Paulius Puzinauskas
Hybrid vehicle engines modified for high exhaust gas recirculation (EGR) are a good choice for high efficiency and low NOx emissions. Such operation can result in an HEV when a downsized engine is used at high load for a large fraction of its run time to recharge the battery or provide acceleration assist. However, high EGR will dilute the engine charge and may cause serious performance problems such as incomplete combustion, torque fluctuation, and engine misfire. An efficient way to overcome these drawbacks is to intensify tumble leading to increased turbulent intensity at the time of ignition. The enhancement of turbulent intensity will increase flame velocity and improve combustion quality, therefore increasing engine tolerance to higher EGR. It is accepted that the detailed experimental characterization of flow field near top dead center (TDC) in an engine environment is no longer practical and cost effective.
2010-04-12
Technical Paper
2010-01-0540
Pouria Mehrani, Harry C. Watson
Cyclic variability in spark ignition engine combustion, especially at high dilution through lean burn or high EGR rates, places limits on in-cylinder NOx reduction and thermal efficiency. Flame wrinkling, resulting from interactions with turbulence, is a potential source of cyclic variations in turbulence. Previous studies have shown that flame kernels are subject to significant distortions when they are smaller than the integral length scale of turbulence. With the assumption that flame development is not subject to noticeable variations, after it reaches the integral length scale, the authors have shown that turbulent-burning-caused combustion variability can be successfully modeled as a function of laminar flame speed and turbulence intensity. This paper explores the contributions of flame wrinkling to flame kernel growth variation. As the kernel growth problem is complex, this study only explores one of the many aspects of the problem.
2010-04-12
Technical Paper
2010-01-0544
Kentaro Watanabe, Shingo Ito, Tadashi Tsurushima
Gasoline engines employ various mechanisms for improvement of fuel consumption and reduction of exhaust emissions to deal with environmental problems. Direct fuel injection is one such technology. This paper presents a new quasi-dimensional combustion model applicable to direct injection gasoline engine. The Model consists of author's original in-cylinder turbulence and mixture homogeneity sub model suitable for direct fuel injection conditions. Model validation results exhibit good agreement with experimental and 3D CFD data at steady state and transient operating conditions.
2011-04-12
Technical Paper
2011-01-0269
Adam Bryant, Joseph Beno, Damon Weeks
Battlefield reconnaissance is an integral part of today's integrated battlefield management system. Current reconnaissance technology typically requires land based vehicle systems to observe while stationary or, at best, significantly limits travel speeds while collecting data. By combining current Canadian Light Armored Vehicle based reconnaissance systems with the Center for Electromechanics (CEM) electronically controlled active Electromechanical Suspension System (EMS), opportunities exist to substantially increase cross-country speeds at which useful reconnaissance data may be collected. This report documents a study performed by The University of Texas Center for Electromechanics with funding from L3-ES to use existing modeling and simulation tools to explore potential benefits provided by EMS for reconnaissance on the move.
2011-04-12
Journal Article
2011-01-0334
Jim Cowart, Matthew Carr, Pat Caton, Lars Stoulig, Dianne Luning-Prak, Andrew Moore, Leonard Hamilton
Synthetic diesel fuels from Fischer-Tropsch or hydrotreating processes have high cetane numbers with respect to conventional diesel fuel. This study investigates diesel combustion characteristics with these high cetane fuels. A military jet fuel (JP-5 specification), a Fischer-Tropsch (FT) synthetic diesel, and normal hexadecane (C16), a pure component fuel with defined cetane number of 100, are compared with operation of conventional military diesel fuel (F-76 specification). The fuels are tested in a AM General GEP HMMWV engine, an indirect-injection, largely mechanically-controlled diesel engine. Hundreds of thousands of these are in current use and are projected to be in service for many years to come. Experimental testing showed that satisfactory operation could be achieved across the speed-load operating map even for the highest cetane fuel (normal hexadecane). The JP-5, FT, and C16 fuels all showed later injection timing.
2011-04-12
Technical Paper
2011-01-0258
Yang Yang, William Liou, James Sheng, David Gorsich, Sudhakar Arepally
Ground vehicle subjecting to a blast can sustain vehicle damages and occupant injuries. Direct blast thermal and force loadings compromise vehicle structural integrity and cause damages. Computer simulations of vehicle blast wave damages can be obtained by solving the gas dynamics of the blast wave and the structural dynamics of the vehicle, through a projection of the wave's impact on the vehicle structure. There are various possible ways that the blast can cause injuries to the vehicle occupants, such as direct collision with objects instantly accelerated by the blast pressure and impact by the secondary shock waves transmitted through the platform structure. This paper describes a parallel computer simulation methodology that can potentially be applied to predict the structure damage and the associated occupant kinematics during a blast event by solving the multi-physics problem of fluid dynamics, solid dynamics, and multi-body dynamics.
2011-04-12
Technical Paper
2011-01-0266
J.Y. Wong
With growing globalization of the economy, to gain a competitive edge in world markets shortening the product development cycle is crucial. Virtual product development is, therefore, being actively pursued in the off-road vehicle industry. To implement this process successfully, the development of comprehensive and realistic computer-aided methods for performance and design evaluation of off-road vehicles is of vital importance. To be useful to the engineer in industry for the development and design of new products, the computer-aided methods should take into account all major vehicle design parameters and pertinent terrain characteristics. They should be based on the understanding of the physical nature and the mechanics of vehicle-terrain interaction. Their capabilities should be substantiated by test data.
2011-04-12
Technical Paper
2011-01-0436
Alejandra Paola Polanco, Luis Munoz
In this paper the comfort sensitivity to the variation of the inertia parameters is studied. For the theoretical approach, two computational models that predict the comfort response of a vehicle are developed and verified. These models are used to study the effect of a change on the inertial properties of the car on its comfort response. The models are developed on a commercial multi-body package and also implementing handwritten equations with a numerical integration algorithm. The influence of the inertial properties on comfort is also experimentally studied. Both approaches use two different road patterns as input generating a roll and pitch excitation. An allowed uncertainty on the inertia properties is proposed, based on the sensitivity to those properties.
2011-04-12
Journal Article
2011-01-0437
Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies.
2011-04-12
Technical Paper
2011-01-0399
Andre Ferrarese, Jason Bieneman, David J. Domanchuk, Thomas Smith, Thomas Stong, Peter Einberger
Changing emission legislation limits are challenging the engine developers in many aspects. Requirement to improve combustion and engine efficiency have resulted in increased loads and higher levels of abrasive particles within the engine environment. Concerning piston rings and piston ring grooves, such engine modifications are leading to critical tribological conditions and side wear is becoming a key issue in the design of these components. Historically one of the most common forms of side wear protection on piston rings has been chromium plate. This solution has limitations on durability (low thickness) and on topography (rough surfaces). In response to these limitations, nitrided stainless steel top rings have been used to improve the side protection; it is harder and typically has a smoother surface finish when compared to chromium coating.
2011-04-12
Technical Paper
2011-01-0390
Naoki Kurimoto, Masayuki Suzuki, Mutsumi Yoshino, Yoshiaki Nishijima
A response surface model of a diesel spray, parameterized by the internal geometries of a nozzle, is established in order to design the nozzle geometries optimally for spray mixing. The explanatory variables are the number of holes, the hole diameter, the inclined angle, the hole length, the hole inlet radius, K-factor and the sac diameter. The model is defined as a full second-order polynomial model including all the first-order interactions of the variables, and a total of 40 sets of numerical simulations based on D-optimal design are carried out to calculate the partial regression coefficients. Partial regression coefficients that deteriorate the estimate accuracy are eliminated by a validation process, so that the estimate accuracy is improved to be ±3% and ±15% for the spray penetration and the spread, respectively. Then, the model is applied to an optimization of the internal geometries for the spray penetration and the spray spread through a multi-objective genetic algorism.
2011-04-12
Technical Paper
2011-01-0675
Riccardo Scarcelli, Thomas Wallner, Nicholas Matthias, Victor Salazar, Sebastian Kaiser
This paper performs a parametric analysis of the influence of numerical grid resolution and turbulence model on jet penetration and mixture formation in a DI-H2 ICE. The cylinder geometry is typical of passenger-car sized spark-ignited engines, with a centrally located single-hole injector nozzle. The simulation includes the intake and exhaust port geometry, in order to account for the actual flow field within the cylinder when injection of hydrogen starts. A reduced geometry is then used to focus on the mixture formation process. The numerically predicted hydrogen mole-fraction fields are compared to experimental data from quantitative laser-based imaging in a corresponding optically accessible engine. In general, the results show that with proper mesh and turbulence settings, remarkable agreement between numerical and experimental data in terms of fuel jet evolution and mixture formation can be achieved.
2011-04-12
Technical Paper
2011-01-0676
Fuming Xiao, Ghazi A. Karim
The dual-fuel engine represents in principle a simple flexible approach to employing gaseous fuels in conventional diesel engines. Compared to the use of hydrogen in spark ignition engines, there is relatively limited information about its effect when present as a supplementary fuel in suitably modified conventional compression ignition engines. This is especially for engines of the IDI type and when employing only low concentrations of hydrogen in the intake air while retaining the injection of large diesel fuel quantities. In the present contribution, a 3D-CFD model based on KIVA 3, developed with a “reduced” detailed chemical kinetics of 294 elementary reaction steps with 79 chemical species for diesel fuel combustion which includes 20 steps for the oxidation of hydrogen, is outlined.
2011-04-12
Journal Article
2011-01-0681
Ming-Chia Lai, Yi Zheng, Xing-Bin Xie, Seoksu Moon, Zunping Liu, Jian Gao, Xusheng Zhang, Kamel Fezzaa, Jin Wang, Junmei Shi
It is well know that the internal flow field and nozzle geometry affected the spray behavior, but without high-speed microscopic visualization, it is difficult to characterize the spray structure in details. Single-hole diesel injectors have been used in fundamental spray research, while most direct-injection engines use multi-hole nozzle to tailor to the combustion chamber geometry. Recent engine trends also use smaller orifice and higher injection pressure. This paper discussed the quasi-steady near-nozzle diesel spray structures of an axisymmetric single-hole nozzle and a symmetric two-hole nozzle configuration, with a nominal nozzle size of 130 μm, and an attempt to correlate the observed structure to the internal flow structure using computational fluid dynamic (CFD) simulation. The test conditions include variation of injection pressure from 30 to 100 MPa, using both diesel and biodiesel fuels, under atmospheric condition.
2011-04-12
Technical Paper
2011-01-0657
Bashar AbdulNour, Mark Doroudian, Mohsen Battoei-Avarzaman
The performance of ground vehicles of all types is influenced by the cooling and ventilation of the engine compartment. An increased heat load into the engine compartment occurs after engine shut down. Heat is transferred from the hot components within the engine compartment by natural convection to the surrounding air and by radiation to the adjacent surfaces. The heat is then dissipated to the ambient mostly by convection from the exterior surfaces. The objective of this study is to develop a Computational Fluid Dynamics (CFD) simulation methodology to predict the airflow velocity and temperature distributions within the engine compartment, as well as the surface temperature of critical engine components during the after-boil condition. This study was conducted using a full-scale, simplified engine compartment of an armored combat vehicle. Steady-state simulation was performed first to predict the condition prior to engine shut down.
2011-04-12
Technical Paper
2011-01-0656
Jason A. Lustbader, John P. Rugh, Brianna R. Rister, Travis S. Venson
In the United States, intercity long-haul trucks idle approximately 1,800 hrs per year primarily for sleeper cab hotel loads, consuming 838 million gallons of diesel fuel [1]. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working on solutions to this challenge through the CoolCab project. The objective of the CoolCab project is to work closely with industry to design efficient thermal management systems for long-haul trucks that keep the cab comfortable with minimized engine idling. Truck engine idling is primarily done to heat or cool the cab/sleeper, keep the fuel warm in cold weather, and keep the engine warm for cold temperature startup. Reducing the thermal load on the cab/sleeper will decrease air conditioning system requirements, improve efficiency, and help reduce fuel use. To help assess and improve idle reduction solutions, the CoolCalc software tool was developed.
2010-04-12
Technical Paper
2010-01-1140
Shawky Hegazy, Corina Sandu
This paper presents a six degree of freedom full vehicle model simulating the testing of heavy truck suspensions to evaluate the ride comfort and stability using actual characteristics of gas charged single tube shock absorbers. The model is developed using one of the commercial multi-body dynamics software packages, ADAMS. The model incorporates all sources of compliance: stiffness and damping with linear and non-linear characteristics. The front and the rear springs and dampers representing the suspension system were attached between the axles and the vehicle body. The front and the rear axles were attached to a wheel spindle assembly, which in turn was attached to the irregular drum wheel, simulating the road profile irregularities. As a result of the drum rotation, sudden vertical movements were induced in the vehicle suspension, due to the bumps and rebounds, thus simulating the road profile.
2010-04-12
Technical Paper
2010-01-1135
Krishna Prasad Balike, Subhash Rakheja, Ion Stiharu
Automotive suspensions invariably exhibit asymmetric damping properties in compression and rebound, which is partly attributed to asymmetric damping and in-part to the suspension linkage kinematics together with tire lateral compliance. Although automotive suspensions have invariably employed asymmetric damping, the design guidelines and particular rationale for such asymmetry has not been explicitly defined. The influences of damper asymmetry together with the suspension kinematics and tire lateral compliance on the dynamic responses of a vehicle are investigated analytically under bump and pothole excitations, and the results are interpreted in view of potential design guidance. A quarter-car kineto-dynamic model of the road vehicle employing a double wishbone type suspension comprising a strut with linear spring and multiphase asymmetric damper is formulated for the analyses.
2010-04-12
Technical Paper
2010-01-1139
Mike J. Johnston, Rob Rieveley, Jennifer Johrendt, Bruce Minaker
Though the purpose of a vehicle's suspension is multi-faceted and complex, the fundamentals may be simply stated: the suspension exists to provide the occupants with a tolerable ride, while simultaneously ensuring that the tires maintain good contact with the ground. At the root of the familiar ride/handling compromise, is the problem that tuning efforts which improve either grip or handling are generally to the detriment of the other. This study seeks to set forth a clear means for examining the familiar ride/handing compromise, by first exploring the key ideas of these terms, and then by describing the development of content-rich metrics to permit a direct optimization strategy. For simplicity, the optimization problem was examined in a unilateral manner, where heave (vertical; z-axis) behaviour is examined in isolation, though the methods described herein may be extended to pitch and roll behaviour as well.
Viewing 1 to 30 of 20059

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