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Viewing 1 to 30 of 6085
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.
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
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
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
2011-01-0656
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.
2011-04-12
Technical Paper
2011-01-0240
Saurav Talukdar, Salil Kulkarni
The planar rigid bicycle model is one of the most popular models used in vehicle dynamics. It has widely been used in studying vehicle handling characteristics and designing steering control system for vehicles. This paper analyses a modified dynamic model called the "Elastic Bicycle Model." This model improves upon the classical bicycle model by taking into account the flexibility of the vehicle frame by using concepts from the Euler beam theory. Complete set of the resulting dynamic equations of this model are presented. Non-dimensional versions of the equations are used to investigate the steady state response of the model. Finally, the results of the response study obtained by modeling a small truck with an elastic model and the classical bicycle model are presented. These include the steady state solutions as function of different parameters as well as a transient solution in response to a saw-tooth steering input and a step input. Octave® has been used for simulation purpose.
2011-04-12
Journal Article
2011-01-0183
Brad Hopkins, Saied Taheri
Models for off-road vehicles, such as farm equipment and military vehicles, require an off-road tire model in order to properly understand their dynamic behavior on off-road driving surfaces. Extensive literature can be found for on-road tire modeling, but not much can be found for off-road tire modeling. This paper presents an off-road tire model that was developed for use in vehicle handling studies. An on-road, dry asphalt tire model was first developed by performing rolling road force and moment testing. Off-road testing was then performed on dirt and gravel driving surfaces to develop scaling factors that explain how the lateral force behavior of the tire will scale from an on-road to an off-road situation. The tire models were used in vehicle simulation software to simulate vehicle behavior on various driving surfaces. The simulated vehicle response was compared to actual maximum speed before sliding vs. turning radius data for the studied vehicle to assess the tire model.
2011-04-12
Journal Article
2011-01-0178
Jeff Howell
Vehicles on the road operate in the turbulent flow field resulting from the combined effects of the natural wind and the wakes of other vehicles. While substantial data exists on the properties of the natural wind, much less information is available for the wake properties of road vehicles. The wake information available for road vehicle shapes is mainly restricted to the near wake region, but to understand the vehicle operating environment it is the wake downstream of this region which is of interest. To determine the range of this area of interest requires some knowledge of the decay of the wake properties. From wind tunnel studies using small simple bluff bodies in free stream and in ground proximity the principle wake properties, velocity deficit and peak turbulence intensity have been measured. The maximum velocity deficit is shown to approximately decay with x-2/3, where x is the distance downstream, while turbulence intensity decays at a slightly slower rate.
2011-04-12
Technical Paper
2011-01-0174
Lisa Larsson, Torbjörn Wiklund, Lennart Löfdahl
The aim of the study was to investigate the cooling performance of two cooling package positions for distribution vehicles by using Computational Fluid Dynamics. The first cooling package was positioned in the front of the vehicle, behind the grill and the second position was at the rear of the vehicle. Each case was evaluated by its cooling performance for a critical driving situation and its aerodynamic drag at 90 km/h, where the largest challenge of an alternative position is the cooling air availability. The geometry used was a semi-generic commercial vehicle, based on a medium size distribution truck with a heat rejection value set to a fixed typical level at maximum power for a 13 litre Euro 6 diesel engine. The heat exchangers included in the study were the air conditioning condenser, the charge air cooler and the radiator. It was found that the main problem with the rear mounted cooling installation was the combination of the fan and the geometry after the fan.
2011-04-12
Journal Article
2011-01-0162
Ming Jiang, Huaizhu Wu, Kebing Tang, Minsuk Kim, Sivapalan Senthooran, Heinz Friz, Yingzhe Zhang
The engineering process in the development of commercial vehicles is facing more and more stringent emission regulations while at the same time the market demands for better performance but with lower fuel consumption. The optimization of aerodynamic performance for reduced drag is a key element for achieving related performance targets. Closely related to aerodynamics are wind noise and cabin soiling and both of them are becoming more and more important as a quality criterion in many markets. This paper describes the aerodynamic and aero-acoustic performance evaluation of a Dongfeng heavy truck using digital simulation based on a LBM approach. It includes a study for improving drag within the design of a facelift of the truck. A soiling analysis is performed for each aerodynamic result by calculating the accumulation of particles emitted form the wheels on the cabin. One of the challenges in the development process of trucks is that different cabin types have to be designed.
2011-04-12
Technical Paper
2011-01-0090
Wei Liu, Wenku Shi Sr
In this paper, a Magneto-Rheological (MR) fluid semi-active suspension system was tested on a commercial vehicle, a domestic light bus, to determine the performance improvements compared to passive suspensions. MR fluid is a material that responds to an applied magnetic field with a significant change in its rheological behavior. When the magnetic field is applied, the properties of such a fluid can change from a free-flowing, low viscosity fluid to a near solid, and this change in properties takes place in a few milliseconds and is fully reversible. A quarter suspension test rig was built out to test the nonlinear performance of MR damper. Based on a large number of experimental data, a phenomenological model of MR damper based on the Bouc-Wen hysteresis model was adopted to predict both the force-displacement behavior and the complex nonlinear force-velocity response.
2011-04-12
Technical Paper
2011-01-0651
Joshua Pryor, Matt Pierce, Eric Fremond, Yanick Michou
This paper presents the efforts done by Volvo 3P, through a partnership with ThermoAnalytics Inc, to develop transient thermal simulation methodologies of the under hood of a truck. The verification process for the hot spots analysis currently in use at Volvo 3P is described and the key transient situations for the hot spots analysis are identified: hot shutdown, DPF regeneration and long drive cycle, are currently only covered by physical testing late in the project, contrary to steady-state operating conditions that are already managed through simulations in the early stage of the development phase. The goal of this work is to develop simulation methodologies for these transient situations which are likely to increase the efficiency of the verification process. The key issues to be satisfied are to minimize the model development and the simulation times while achieving an acceptable accuracy level.
2013-05-13
Journal Article
2013-01-2009
Pranab Saha, James Haylett, Ranjit K. Roy
This paper discusses a design of experiments (DOE) analysis that was performed to understand relevant factors that influence the acoustic performance of a sound package part used in the commercial vehicle industry for the floor mat application. The acoustic performance of the sound package part which is a double wall system and constructed of a barrier and cellular decoupler material is expressed in terms of sound transmission loss (STL). An experiment was designed using the Taguchi DOE technique with three factors and three levels to acquire the STL data and is discussed in the paper. The results of the DOE analysis and the confidence in the model are discussed as well as the benefits of predicting expected STL performances are mentioned in the paper.
2013-05-13
Technical Paper
2013-01-2008
Steven Jorro, John Zehme, Sam Mleczko, Eglind Myftiu, Blake Rager
The reduction of full acceleration truck pass-by noise conforming to Type ECE-51 regulation (Reference 1) was predicted in a hemi-anechoic chassis dynamometer chamber with microphone arrays and compared with actual test track results. This gave a close match to the track data, with both showing a 4 dB reduction in the A-weighted overall noise level after identical acoustic treatments were applied. Noise control materials were selected to perform as acoustic barriers and absorbers. These were optimized by analyzing the 1/3 octave spectra, determining dominant frequency bands, in critical source locations and engine speeds, and using combinations that dissipate or contain energy well within those bands. With the truck being stationary while tested, important source locations could be quickly identified both subjectively and with localization tools such as Beamforming.
2013-05-13
Technical Paper
2013-01-2010
Jiantie Zhen, Aaron Brames, Tyler Williams, Clinton Metzger
NVH is gaining importance in the quality perception of off-highway machine performance and operator comfort. Booming noise, a low frequency NVH phenomenon, can be a significant sound issue in an off-highway machine. In order to increase operator comfort by decreasing the noise levels and noise annoyance, a tuned mass damper (TMD) was added to the resonating panel to suppress the booming. Operational deflection shapes (ODS) and experimental modal analysis (EMA) were performed to identify the resonating panels, a damper was tuned in the lab and on the machine to the specific frequency, machine operational tests were carried out to verify the effectiveness of the damper to deal with booming noise.
2013-05-13
Technical Paper
2013-01-2011
Mahender Singh
Refuse Trucks are used to pick up garbage from houses. These trucks have huge robotic arms connected to the frame which are operated by hydraulic mechanism operated by the driver sitting inside the cab of the truck. The operator of the truck controls the robotic arm using a lever. Once the truck is positioned aside the garbage can, the operator moves the robotic arm outwards, grabs hold of the garbage can, picks up the garbage can and dumps the garbage into the truck. During this operation, the frame articulates and moves due to the frame suspension causing the cab to move along with the frame. This operation is performed about 1000 times a day, 5days a week for 12 years which could result in some amount of damage to the cab over its life. Since the time rate of application of the forces during the Automatic Side Loading operation is small compared to the lowest flexible mode of the cab, modal amplification is considered unlikely.
2013-04-08
Technical Paper
2013-01-1343
Marco Mammetti, David Gallegos, Alex Freixas, Jordi Muñoz
The focus of the work is to carry out a study of the relative impact of the rolling resistance measurements on CO₂ emission and fuel consumption reduction for heavy-duty vehicles. For the purpose of the study, friction coefficients of the tires from tire test machine according to UN/ECE Regulation No 117 test procedure have been used. The rolling resistance coefficient has also been obtained from SAE J1263 and SAE J2263 procedure for coast-down determination on proving ground. The fuel consumption has been simulated and tested on the proving ground by following FIGE standard cycle and stabilized speed conditions. A simulation tool has been developed and validated by testing different rolling resistance coefficient tires, analyzing their effect on the fuel consumption. The analysis of the contribution of the tires to fuel consumption achieved on the test track has been correlated with the experimental results and those obtained from the simulation tool.
2013-04-08
Technical Paper
2013-01-1354
Wenguang Wu, Zhengqi Gu
Electric wheel dump trucks are mainly used in open pit mines, where the working environment is very harsh and the driver's continuous working time is extremely long, therefore, the ride comfort of the truck is pretty important. This paper evaluates and optimizes the ride comfort, according to ISO2631, and Chinese standard GB/T4970-1996 and Chinese standard QC/T76.8-1993, while the ride comfort test had been done in a open pit mine. After the test data was analyzed, the results showed that the ride comfort of this truck needs to be improved and optimized. The multi-body system dynamic model was built in MATLAB/SIMULINK for this dump truck, to simulate the realistic working condition using a D-class road, which was reconstructed according to ISO/DIS8608 and Chinese standard GB7031-86, while the simulation results were in coincidence with the test ones.
2013-09-24
Journal Article
2013-01-2474
Helmut Theissl, Alois Danninger, Thomas Sacher, Herwig Ofner, Erwin Schalk
This paper describes a method for optimization of engine settings in view of best total cost of operation fluids. Under specific legal NOX tailpipe emissions requirements the engine out NOX can be matched to the current achievable SCR NOX conversion efficiency. In view of a heavy duty long haul truck application various specific engine operation modes are defined. A heavy duty diesel engine was calibrated for all operation modes in an engine test cell. The characteristics of engine operation are demonstrated in different transient test cycles. Optimum engine operation mode (EOM) selection strategies between individual engine operation modes are discussed in view of legal test cycles and real world driving cycles which have been derived from on-road tests.
2013-09-24
Technical Paper
2013-01-2466
Steffen Daum, Sadanand Bhosale, Gernot Graf, Dipankar Ray
The increasingly stringent emission legislations provide a continuous challenge for the non-road market. In parallel to transient test cycles, increased emission durability as well as real driving emissions must be fulfilled. The enormous diversification of engines within the different power classes as well as the specific operation requirements regarding various duty cycles, robustness and durability, requires specific solutions to meet these legal limits. The publication shows a cost efficient, reliable and durable approach based on the example of a tractor engine jointly developed by Mahindra & Mahindra Ltd. (M&M) and AVL. It was found that a naturally aspirated (NA) application equipped with common rail and combined with cooled exhaust gas recirculation (EGR) is able to fulfill all legal Environmental Protection Agency (EPA) Tier 4 requirements with a minimum effort on the exhaust aftertreatment side by using only a diesel oxidation catalyst.
2013-09-24
Technical Paper
2013-01-2451
Lian Soto Izquierdo, Gian Gomes Marques, Vanessa Balieiro
Studies aimed at partial or total use of renewable fuels in diesel engines has increasingly attracted the interest of the automotive industry, in particular due to its characteristics of strength, durability and greater thermal efficiency. The oil esters derived from biological sources, who receive the generic name for biodiesel, is one of the alternatives used internationally. Their physicochemical properties are similar to diesel oil for providing an acceptable dynamic process of preparation and combustion in the engine. This paper presents and evaluates the results of experimental tests carried out in four trucks used exclusively B20 biodiesel (20% biodiesel and 80% petroleum diesel), and one with B100 (pure biodiesel), in real operating conditions.
2013-09-24
Technical Paper
2013-01-2427
Lorenzo Serrao, Giulio Ornella, Gilberto Burgio, Ettore Cosoli
The paper illustrates the development of a hydraulic hybrid powertrain concept for off-highway vehicles, which is the result of a three-year program at Dana's advanced technology centers. Engineers have conducted extensive simulations and tests while equipping a demonstration vehicle to determine feasibility, develop advanced features, and quantify benefits of hydraulic hybridization for traction. The system concept and operation as well as its development process are illustrated, focusing the system engineering principles and on the model-based approach to system design, control, and energy analysis. Experimental results are provided.
2013-09-24
Technical Paper
2013-01-2418
Sreedhar Reddy, Vignesh T Shekar
There have always been different approaches when it comes to ‘Bus body architecture’. The design approach has gone through different phases namely, chassis based, semi integral, integral and monocoque. Equally varied is the choice of material for bus super structure. The predominantly used ones are - mild steel with galvanization, stainless steel (SS) and aluminum. This paper discusses the rationale behind choosing stainless steel for the complete bus structure. With rapid development in infrastructure and public mass transit system, it has become imperative to have a robust structure for buses that is durable and crash worthy. Among the family of stainless steels, ferritic stainless steel exhibits excellent mechanical properties with corrosion resistance and better strength to weight ratio compared to the galvanized mild steel.
2013-09-24
Technical Paper
2013-01-2417
Lisa Henriksson, Erik Dahl, Peter Gullberg, Lennart Lofdahl
This paper presents results and a Computational Fluid Dynamics (CFD) method for simulation of a detailed louvered fin for a multi-louvered compact heat-exchanger. The airflow was angled at 90°, +30° and −30° relative to the heat-exchanger to evaluate changes in static pressure drop and airflow characteristics. The investigation was based on three heat-exchangers with thicknesses of 52mm and two of 19mm. One period of a detailed louvered fin was simulated for two airflows for each heat-exchanger. The pressure drop data was thereafter compared to experimental data from a full-size heat-exchanger. From the pressure drop and the airflow characteristic results recommendations were made that those kinds of simulations could be defined as steady state, and with the kω-SST turbulence model. For the same heat-exchanger angle the airflow within the core was similar, with a turbulent characteristic behind it.
2013-09-24
Technical Paper
2013-01-2423
Rishikesh Venugopal, Neerav Abani, Ryan MacKenzie
This paper presents analytical and measured results on the effects of injection pattern design on piston thermal management in an Opposed-Piston, Two-Stroke (OP2S) diesel engine. The OP2S architecture investigated in this work comprises two opposing pistons forming an asymmetric combustion chamber with two opposing injectors mounted on the cylinder wall. This unique configuration offers opportunities to tailor the injection pattern to control the combustion heat flux and resulting temperatures on the piston surfaces while optimizing combustion simultaneously. This study utilizes three-dimensional (3D) computational fluid dynamics (CFD) with state-of-the-art spray, turbulence and combustion models that include detailed chemistry to simulate the in-cylinder combustion and the associated flame/wall interactions. In addition, the measurements comprise a real-time thermocouple system, which allows for up to 14 locations to be monitored and recorded on the intake and exhaust pistons.
2013-09-24
Journal Article
2013-01-2421
Donald W. Stanton
With increasing energy prices and concerns about the environmental impact of greenhouse gas (GHG) emissions, a growing number of national governments are putting emphasis on improving the energy efficiency of the equipment employed throughout their transportation systems. Within the U.S. transportation sector, energy use in commercial vehicles has been increasing at a faster rate than that of automobiles. A 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected from 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double.
2013-11-27
Technical Paper
2013-01-2755
Saurabh gupta, Robesh Maity Sr, Shrirang Kulkarni cEng
Paddy farming in India needs extensive water usage. Due to the rapidly declining ground water and ever increasing monsoon uncertainty, there is significant drive on water conservation for paddy farming through sustainable agriculture practices. The wide variability of irrigation water in Indian rice field, as high as 160 mm, necessitates an extra 100 mm of water in the field to provide complete water coverage. This is primarily due to inaccurate manual land leveling, often practiced in Indian paddy farming. In the present work, architecture of laser land leveler has been created by integrating low cost electronics, hydraulics and GPS technology. This paper will provide an overview of the current practices and suitable operating mode to meet the future demand on land leveling. The presentation would compare the laser land leveler with GPS land leveler solution architectures. The technological differences along with individual merits and limitations would be detailed.
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