Display:

Results

Viewing 1 to 30 of 3045
2017-07-10
Technical Paper
2017-28-1921
Jyotirmoy Barman
Engine down speeding is rapidly picking up momentum in the many segment of world market. Numerous engines down speeding packages from OEM have been tailored to take advantage of the increased efficiencies associated with engine down speeding. Running at a lower rpm provides numerous advantages. The most obvious of these is reduced fuel consumption, since the engine can spend more time running within its optimum efficiency range. By down speeding, the engine is made to run at low speeds and with high torques. For the same power the engine is operated at higher specific load (BMEP) which results in higher efficiency and reduced fuel consumption (BSFC). The reasons for increased fuel efficiency are reduced engine friction due to low piston speeds, reduced relative heat transfer and increased thermodynamic efficiency.
2017-06-05
Technical Paper
2017-01-1791
David Neihguk, Shreyas Fulkar
Abstract Parametric model of a production hybrid (made up of reactive and dissipative elements) muffler for tractor engine is developed to compute the acoustic Transmission Loss (TL). The objective is to simplify complex muffler acoustic simulations without any loss of accuracy, robustness and usability so that it is accessible to all product development engineers and designers. The parametric model is a 3D Finite Element Method (FEM) based built in COMSOL model builder which is then converted into a user-friendly application (App) using COMSOL App builder. The uniqueness of the App lies in its ability to handle not only wide range of parametric variations but also variations in the physics and boundary conditions. This enables designers to explore various design options in the early design phase without the need to have deep expertise in a specific simulation tool nor in numerical acoustic modeling.
2017-06-05
Technical Paper
2017-01-1835
Nader Dolatabadi, Ramin Rahmani, Stephanos Theodossiades, Homer Rahnejat, Guy Blundell, Guillaume Bernard
Abstract Clutches are commonly utilised in passenger type and off-road heavy-duty vehicles to disconnect the engine from the driveline and other parasitic loads. In off-road heavy-duty vehicles, along with fuel efficiency start-up functionality at extended ambient conditions, such as low temperature and intake absolute pressure are crucial. Off-road vehicle manufacturers can overcome the parasitic loads in these conditions by oversizing the engine. Caterpillar Inc. as the pioneer in off-road technology has developed a novel clutch design to allow for engine downsizing while vehicle’s performance is not affected. The tribological behaviour of the clutch will be crucial to start engagement promptly and reach the maximum clutch capacity in the shortest possible time and smoothest way in terms of dynamics. A multi-body dynamics model of the clutch system is developed in MSC ADAMS.
2017-06-05
Technical Paper
2017-01-1837
Paul R. Donavan, Carrie Janello
Abstract Acoustic beamforming was used to localize noise sources on heavy trucks operating on highways in California and North Carolina at a total of 20 sites. Over 1,200 trucks were measured under a variety of operating conditions, including cruise on level highways, on upgrades, down degrades, low speed acceleration, and for various speeds and pavements. The contours produced by the beamforming measurements were used to identify specific source contributions under these conditions and for a variety of heavy trucks. Consistently, the highest noise levels were seen at the tire-pavement interface, with lesser additional noise radiated from the engine compartment. Noise from elevated exhaust stacks was only documented for less than 5% of the trucks measured. The results were further reduced to produce vertical profiles of noise levels versus height above the roadway. The profiles were normalized to the highest noise level at ground level.
2017-06-05
Technical Paper
2017-01-1871
Nobutaka Tsujiuchi, Masahiro Akei, Akihito Ito, Daisuke Kubota, Koichi Osamura
Abstract This paper describes new method for selecting optimal field points in Inverse-Numerical Acoustic analysis (INA), and its application to construction of a sound source model for diesel engines. INA identifies the surface vibration of a sound source by using acoustic transfer functions and actual sound pressures measured at field points located near the sound source. When measuring sound pressures with INA, it is necessary to determine the field point arrangement. Increased field points leads to longer test and analysis time. Therefore, guidelines for selecting the field point arrangement are needed to conduct INA efficiently. The authors focused on the standard deviations of distance between sound source elements and field points and proposed a new guideline for optimal field point selection in our past study. In that study, we verified the effectiveness of this guideline using a simple plate model.
2017-06-05
Technical Paper
2017-01-1875
Martino Pigozzi, Flavio Faccioli, Carlo Ubertino, Davide Allegro, Daniel Zeni
Abstract Within recent years, passenger comfort has become a main focus of the automotive industry. The topic is directly connected with acoustics, since sounds and noises have a major impact on the well-being of vehicle occupants. So-called “noise control” focuses on directly optimizing acoustic comfort by implementing innovative materials or geometries for automotive components and systems. One possibility to optimize the acoustics within a vehicle is connected to the phenomenon of sloshing in Selective Catalytic Reduction (SCR) tanks. Sloshing is a noise which is generated during normal driving situations by the motion of the Diesel Exhaust Fluid (DEF) in the tank. Until now, no procedure for measuring sloshing noise in SCR tanks has been defined, and neither a specific acoustic target which the SCR tanks need to fulfil.
2017-04-11
Journal Article
2017-01-9176
Jitesh Shukla, A Grinspan, Jeyanthi subramanian
Abstract Lifting axles are auxiliary axles that provide increased load carrying capacity in heavy commercial vehicles. Lift axle gives better fuel efficiency as well as it reduces the operational costs by means of increasing the loading carrying capacity. These axles are raised when the vehicle is in unloaded condition, thus increasing the traction on remaining wheels and reducing the tire wear which in turn lower down the maintenance cost of the vehicle. Lifting height and force requires to lift the whole mechanism and are two main considerable factors to design the lifting axle mechanism. Although in India currently, the use of lift mechanism of single tire with continuous axle is more common. But in the case of pusher axle, continuous axle is unable to lift more after certain height because of the draft angle of the propeller shaft, and single tire axle which has less load carrying capacity up to 6T (Tons).
2017-03-28
Technical Paper
2017-01-1333
Sasikumar P, C. Sujatha, Chinnaraj K.
Abstract In commercial vehicles, exhaust system is normally mounted on frame side members (FSM) using hanger brackets. These exhaust system hanger brackets are tested either as part of full vehicle durability testing or as a subsystem in a rig testing. During initial phases of product development cycle, the hanger brackets are validated for their durability in rig level testing using time domain signals acquired from mule vehicle. These signals are then used in uni-axial, bi-axial or tri-axial rig facilities based on their severity and the availability of test rigs. This paper depicts the simulation method employed to replicate the bi-directional rig testing through modal transient analysis. Finite Element Method (FEM) is applied for numerical analysis of exhaust system assembly using MSC/Nastran software with the inclusion of rubber isolator modeling, meshing guidelines etc. Finite Element Analysis (FEA) results are in good agreement with rig level test results.
2017-03-28
Technical Paper
2017-01-0890
Yoichiro Nakamura, Masahisa Horikoshi, Yasunori TAKEI, Takahiro Onishi, Yasuhiro Murakami, Chip Hewette
Abstract Heavy duty vehicles take a large role in providing global logistics. It is required to have both high durability and reduced CO2 from the viewpoint of global environment conservation. Therefore lubricating oils for transmission and axle/differential gear box are required to have excellent protection and longer drain intervals. However, it is also necessary that the gear oil maintain suitable friction performance for the synchronizers of the transmission. Even with such good performance, both transmission and axle/differential gear box lubricants must balance cost and performance, in particular in the Asian market. The development of gear oil additives for high reliability gear oil must consider the available base oils in various regions as the additive is a global product. In many cases general long drain gear oils for heavy duty vehicles use the group III or IV base oils, but it is desirable to use the group I/II base oils in terms of cost and availability.
2017-03-28
Technical Paper
2017-01-0869
Job Immanuel Encarnacion, Edwin Quiros
Abstract The Philippine Biofuels Act of 2006 (RA 9367) requires commercial diesel fuel to be mixed with Coconut Methyl Ester (CME) in accordance with the Philippine Clean Air Act of 1999 (RA 8749). As of 2015, the blend percentage is at 2% CME v/v, contrary to the scheduled 5% as stipulated in the biofuels act. Researches done locally showing the performance and emissions of CME-fueled engines are few and thus the basis for the CME percentage increase is still questionable and hampers the drive for the further implementation of the policy. The study investigates the influence of varying percentages of CME blends (2%, 5%, 10%, 15%, 20% v/v) to the performance and emissions of a heavy-duty turbocharged common rail direct injection (CRDI) engine. The engine is run at steady state at partial load (50Nm and 250 Nm) and at near full load (500Nm). Each run is set at three pedal positions, α (25%, 50% and 60%), controlled directly from the engine control unit.
2017-03-28
Technical Paper
2017-01-0957
Ian Smith, Thomas Briggs, Christopher Sharp, Cynthia Webb
Abstract It is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards of 0.20 g/bhp-hr, the National Ambient Air Quality Standards (NAAQS) requirements for ambient ozone will not be met. It is expected that further reductions in NOX emissions from the heavy-duty fleet will be required to achieve compliance with the ambient ozone requirement. To study the feasibility of further reductions, the California Air Resources Board (CARB) funded a research program to demonstrate the potential to reach 0.02 g/bhp-hr NOX emissions. This paper details the work executed to achieve this goal on the heavy-duty Federal Test Procedure (FTP) with a heavy-duty natural gas engine equipped with a three-way catalyst. A Cummins ISX-12G natural gas engine was modified and coupled with an advanced catalyst system.
2017-03-28
Technical Paper
2017-01-0638
Neerav Abani, Nishit Nagar, Rodrigo Zermeno, Michael chiang, Isaac Thomas
Abstract Heavy-duty vehicles, currently the second largest source of fuel consumption and carbon emissions are projected to be fastest growing mode in transportation sector in future. There is a clear need to increase fuel efficiency and lower emissions for these engines. The Opposed-Piston Engine (OP Engine) has the potential to address this growing need. In this paper, results are presented for a 9.8L three-cylinder two-stroke OP Engine that shows the potential of achieving 55% brake thermal efficiency (BTE), while simultaneously satisfying emission targets for tail pipe emissions. The two-stroke OP Engines are inherently more cost effective due to less engine parts. The OP Engine architecture presented in this paper can meet this performance without the use of waste heat recovery systems or turbo-compounding and hence is the most cost effective technology to deliver this level of fuel efficiency.
2017-03-28
Technical Paper
2017-01-0260
Yuanying Wang, Heath Hofmann, Denise Rizzo, Scott Shurin
Abstract This paper presents a computationally-efficient model of heat convection due to air circulation produced by rotor motion in the air gap of an electric machine. The model calculates heat flux at the boundaries of the rotor and stator as a function of the rotor and stator temperatures and rotor speed. It is shown that, under certain assumptions, this mapping has the homogeneity property. This property, among others, is used to pose a structure for the proposed model. The coefficients of the model are then determined by fitting the model to the results of a commercial Computational Fluid Dynamics (CFD) simulation program. The accuracy of the new model is compared to the CFD results, shown an error of less than 0.3% over the studied operating range.
2017-03-28
Technical Paper
2017-01-0560
Mateusz Pucilowski, Mehdi Jangi, Sam Shamun, Changle Li, Martin Tuner, Xue-Song Bai
Abstract Methanol as an alternative fuel in internal combustion engines has an advantage in decreasing emissions of greenhouse gases and soot. Hence, developing of a high performance internal combustion engine operating with methanol has attracted the attention in industry and academic research community. This paper presents a numerical study of methanol combustion at different start-of-injection (SOI) in a direct injection compression ignition (DICI) engine supported by experimental studies. The aim is to investigate the combustion behavior of methanol with single and double injection at close to top-dead-center (TDC) conditions. The experimental engine is a modified version of a heavy duty D13 Scania engine. URANS simulations are performed for various injection timings with delayed SOI towards TDC, aiming at analyzing the characteristics of partially premixed combustion (PPC).
2017-03-28
Technical Paper
2017-01-0528
Eric Miller, Arnaud Konan, Adam Duran
Accurate vehicle parameters are valuable for design, modeling, and reporting. Estimating vehicle parameters can be a very time-consuming process requiring tightly-controlled experimentation. This work describes a method to estimate vehicle parameters such as mass, coefficient of drag/frontal area, and rolling resistance using data logged during standard vehicle operation. The method uses a Monte Carlo method to generate parameter sets that are fed to a variant of the road load equation. The modeled road load is then compared to the measured load to evaluate the probability of the parameter set. Acceptance of a proposed parameter set is determined using the probability ratio to the current state, so that the chain history will give a distribution of parameter sets. Compared to a single value, a distribution of possible values provides information on the quality of estimates and the range of possible parameter values. The method is demonstrated by estimating dynamometer parameters.
2017-03-28
Technical Paper
2017-01-0521
Richard Merrett, John Murray, Doug Kolak
Abstract The development of experimental ORC systems is an extremely complex, time consuming and costly task. Running a range of experiments on a number of different component configurations may be prohibitively expensive and subject to equipment issues and failures. Yet ORC systems offer significant potential for automotive manufacturers to improve vehicle efficiency, reduce fuel consumption and vehicle emissions; the technology is particularly relevant for those involved in the design and/or manufacture of heavy duty trucks. This paper is focused on the validation of a computational ORC system simulation tool against a number of SAE published test results based on the European Stationary Cycle. Such studies on industry standard systems are essential in order to help promote confidence in a virtual prototype approach.
2017-03-28
Technical Paper
2017-01-0846
Raul Payri, Gabriela Bracho, Pedro Marti-Aldaravi, Alberto Viera
In the present work a constant-pressure flow facility able to reach 15 MPa ambient pressure and 1000 K ambient temperature has been employed to carry out experimental studies of the combustion process at Diesel engine like conditions. The objective is to study the effect of orifice diameter on combustion parameters as lift-off length, ignition delay and flame penetration, assessing if the processing methodologies used for a reference nozzle are suitable in heavy duty applications. Accordingly, three orifice diameter were studied: a spray B nozzle, with a nominal diameter of 90 μm, and two heavy duty application nozzles (diameter of 194 μm and 228 μm respectively). Results showed that nozzle size has a substantial impact on the ignition event, affecting the premixed phase of the combustion and the ignition location.
2017-03-28
Technical Paper
2017-01-0725
Kun Wang, Haiying Li, Yufeng Li, jinlong liu, Junting Fan
Abstract In diesel engines, valve avoiding pit (VAP) is often designed on the top of the piston in order to avoid the interference between the valves and the piston during the engine operation. With the continued application of the downsized or high power density diesel engines, the depth of VAP has to be further deepened due to increased valve lift for more air flow into and out of the cylinder and decreased piston top clearance for less HC/CO and soot emissions. The more and more deepening of VAP changes the combustion chamber geometry, the top clearance height and the injector relative position to the piston crown. In this paper, a 3-D in-cylinder combustion model was used for a heavy duty diesel engine to investigate the effects of the depth of VAP on combustion process and emissions. Five depths of VAP were designed in this study.
2017-03-28
Technical Paper
2017-01-0694
Tae Joong Wang, Jong Yoon Lee, Seung Kwon Hwang, Ja Yun Cho, Jeong Keun Park, Woong Gun Lee, Tae Sub Kim, Sang Won Jeong, Tae Kuk Kim
Abstract Doosan Infracore Corporation has developed the combustion system of a brand-new DX12 heavy-duty diesel engine equipped for 38 ~ 50 tonnage excavators and 4.2 ~ 4.5 m3 bucket-size wheel loaders which are mainly targeted to emerging countries. A variety of advanced combustion technologies were incorporated in the design of the DX12 engine to meet Tier3 emission legislation even with a mechanically controlled fuel injection equipment while ensuring around 2 % improvement in fuel consumption as well as over 8 % increase in rated power than its Tier2 predecessor. Mechanical-type diesel engine has a couple of significant advantages especially in terms of cost and maintenance compared to electronic-type counterpart. In addition, mechanical fuel system is better able to tolerate a low fuel quality which is potentially possible in emerging countries.
2017-03-28
Technical Paper
2017-01-0708
Carlos Jorques Moreno, Ola Stenlaas, Per Tunestal
Abstract Factors influencing the effect of pilot-injection on main-injection combustion were investigated using heat release analysis in a heavy-duty diesel engine fuelled with standard diesel fuel, and included the effect of those factors on engine performance and emissions. Combinations of pilot injection parameters i.e. pilot start of injection, pilot mass, pilot-main injection separation, and rail pressure were studied for various operating conditions and combustion phases. It was concluded that the effect of pilot-injection combustion on main injection can be studied based on the phase of pilot combustion at the start of main injection. Four cases were identified: a) main injection during the mixing phase of pilot injection; b) main injection during the premixed phase of pilot combustion; c) main injection during the diffusive phase of pilot combustion and d) main injection after pilot combustion was completed.
2017-03-28
Technical Paper
2017-01-0756
Zhenkuo Wu, Christopher Rutland, Zhiyu Han
Abstract Natural gas is a promising alternative fuel for internal combustion engines due to its rich reserves and low price, as well as good physical and chemical properties. Its low carbon structure and high octane number are beneficial for CO2 reduction and knock mitigation, respectively. Diesel and natural gas dual fuel combustion is a viable pathway to utilize natural gas in diesel engines. To achieve high efficiency and low emission combustion in a practical diesel engine over a wide range of operating conditions, understanding the performance responses to engine system parameter variations is needed. The controllability of two combustion strategies, diesel pilot ignition (DPI) and single injection reactivity controlled compression ignition (RCCI), were evaluated using the multi-dimension CFD simulation in this paper.
2017-03-28
Technical Paper
2017-01-1579
Liang-kuang Chen, Chien-An Chen
Abstract The development of an integrated controller for a 4WS/4WD electric bus is investigated. The front wheel steering angle is assumed to be controlled by the human driver. The vehicle is controlled by the rear wheel steering and the yaw moment that can be generated by the differential torque/brake control on each wheel. The high speed cornering is used as the testing scenario to validate the designed controller. Due to the highly nonlinear and the multiple-input and multiple-output nature, the control design is separated into different stages using the hierarchical layer control concept. The longitudinal speed is controlled using a PI controller together with a rule-based speed modification. The other two control inputs, namely the rear wheel steering and the DYC moment, are then designed using the state-dependent Riccati equation method. The designed controllers are evaluated using computer simulations first, and the simulations showed promising results.
2017-03-28
Technical Paper
2017-01-1490
Silvia Faria Iombriller
Abstract The air suspension development and its applications have becoming increasingly relevant for commercial vehicles to provide dynamic ride comfort to driver and reduce the load impact onto driver and or cargo. This paper shows the analysis and application of an air suspension system for commercial tractor vehicles and its dynamic influence. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension´s stiffness under different conditions of usage, laden and unladed. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions.
2017-03-28
Technical Paper
2017-01-0624
Jiaxin Liu, Sicheng Qin, Yankun Jiang, Shumo He
Abstract In this work, a XD132 Road Roller from XCMG in China was employed as a research basis to study the heat exchange performance of the heat dissipation module under varied working conditions. The module in the XD132 consists of a cooling fan and three radiators. At first, the numerical investigation on the elementary units of radiators was performed to obtain Colburn j factor and Fanning friction f factor, which were used for the ε-NTU method to predict the radiator performance. The fan was numerically tested in a wind test tunnel to acquire the performance curve. The performance data from both investigations were transformed into the boundary conditions of the numerical vehicle model in a virtual tunnel. A field experiment was carried out to validate the simulation accuracy, and an entrance coefficient was proposed to discuss the performance regularity under four working conditions.
2017-03-28
Technical Paper
2017-01-1089
Jose Grande, Julio Abraham Carrera, Manuel Dieguez Sr
Abstract Exhaust Gas Recirculation (EGR) has been in use for many years to control NOx emissions in commercial vehicle applications. Emissions limits are tighter with every new regulation while durability requirements continue to increase, so EGR system manufacturers must be able to provide high performance and robust designs even with high thermal loads. The commercial vehicle market is characterized by lower production rates than passenger car programs and the same engine must cope with multiple applications that have totally different engine calibrations. In some cases it is necessary to design two or more EGR systems for an engine platform, with a consequential impact on cost and development timeline. The optimal design of an EGR system needs to take into consideration several topics related with performance and durability: efficiency and pressure drop, fouling, boiling, thermal fatigue, vibration, pressure fatigue and corrosion among others.
2017-03-28
Technical Paper
2017-01-1575
Andrei Keller, Sergei Aliukov, Vladislav Anchukov
Abstract Trucks are one of the most common modes of transport and they are operated in various road conditions. As a rule, all-wheel drive trucks are equipped with special systems and mechanisms to improve their off-road capability and overall efficiency. The usage of blocked mechanisms for power distribution is one of the most popular and effective ways to improve the off-road vehicle performance. However, the lock of differential may adversely affect the stability and control of vehicle because of the unobvious redistribution of reactions acting on wheels, which consequently leads to poor performance and safety properties. Problems of rational distribution of power in transmissions of all-wheel drive vehicles, as well as research in the field of improving directional stability and active safety systems are among the priorities in modern automotive industry.
2017-03-28
Technical Paper
2017-01-1426
Wesley D. Grimes, Thomas H. Vadnais, Gregory A. Wilcoxson
Abstract The time/distance relationship for a heavy truck accelerating from a stop is often needed to accurately assess the events leading up to a collision. Several series of tests were conducted to document the low speed acceleration performance of a 2016 Freightliner Cascadia truck tractor equipped with a 12-speed automated manual transmission in Auto Mode. Unlike tests in previous papers, the driver never manually shifted gears. These tests included three trailer load configurations and two different acceleration rates. Data were gathered with both a VBOX and with the Detroit Diesel Diagnostic Link (DDDL) software.
2017-03-28
Technical Paper
2017-01-0826
Russell P. Fitzgerald, Christopher Gehrke, Kenth Svensson, Glen Martin
Abstract The performance of five positive k-factor injector tips has been assessed in this work by analyzing a comprehensive set of injected mass, momentum, and spray measurements. Using high speed shadowgraphs of the injected diesel plumes, the sensitivities of measured vapor penetration and dispersion to injection pressure (100-250MPa) and ambient density (20-52 kg/m3) have been compared with the Naber-Siebers empirical spray model to gain understanding of second order effects of orifice diameter. Varying in size from 137 to 353μm, the orifice diameters and corresponding injector tips are appropriate for a relatively wide range of engine cylinder sizes (from 0.5 to 5L). In this regime, decreasing the orifice exit diameter was found to reduce spray penetration sensitivity to differential injection pressure. The cone angle and k-factored orifice exit diameter were found to be uncorrelated.
2017-03-28
Technical Paper
2017-01-1035
Xingyu Xue, John Rutledge
Abstract Diesel engine downsizing aimed at reducing fuel consumption while meeting stringent exhaust emissions regulations is currently in high demand. The boost system architecture plays an essential role in providing adequate air flow rate for diesel fuel combustion while avoiding impaired transient response of the downsized engine. Electric Turbocharger Assist (ETA) technology integrates an electric motor/generator with the turbocharger to provide electrical power to assist compressor work or to electrically recover excess turbine power. Additionally, a variable geometry turbine (VGT) is able to bring an extra degree of freedom for the boost system optimization. The electrically-assisted turbocharger, coupled with VGT, provides an illuminating opportunity to increase the diesel engine power density and enhance the downsized engine transient response.
2017-03-28
Technical Paper
2017-01-1000
Jong Lee, Yu Zhang, Tom Tzanetakis, Michael Traver, Melanie Moses-DeBusk, John Storey, William Partridge, Michael Lance
Abstract Greenhouse gas regulations and global economic growth are expected to drive a future demand shift towards diesel fuel in the transportation sector. This may create a market opportunity for cost-effective fuels in the light distillate range if they can be burned as efficiently and cleanly as diesel fuel. In this study, the emission performance of a low cetane number, low research octane number naphtha (CN 34, RON 56) was examined on a production 6-cylinder heavy-duty on-highway truck engine and aftertreatment system. Using only production hardware, both the engine-out and tailpipe emissions were examined during the heavy-duty emission testing cycles using naphtha and ultra-low-sulfur diesel (ULSD) fuels. Without any modifications to the hardware and software, the tailpipe emissions were comparable when using either naphtha or ULSD on the heavy duty test cycles.
Viewing 1 to 30 of 3045

Filter