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Viewing 1 to 30 of 1175
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
2011-01-0174
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.
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
2013-01-2433
Alberto Boretti
The paper presents a novel concept of very efficient transportation engines for operation with CNG, LNG or LPG. The combustion system permits mixed diesel/gasoline-like operation changing the load by quantity of fuel injected and modulating the premixed and diffusion combustion phases for high fuel energy transfer to piston work. A waste heat recovery system (WHRS) is then recovering the intercooler and engine coolant energy plus the exhaust energy. The WHRS uses a power turbine on the exhaust and a steam turbine feed by a single loop turbo-steamer. The WHRS is the enabler of much faster warm up of the engine and further improvements of the top fuel conversion efficiency to above 50% for the specific case with reduced fuel efficiency penalties changing the load or the speed.
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
2013-01-2395
Mohamed H. Zaher, Sabri Cetinkunt
This paper focuses on comparing the performance of the embedded control of a hybrid powertrain with the original and downsized engine. Optimal robust control approach is used to develop a real time energy management strategy. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in the opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, the motion is driven by gravitational force, or load driven. The real time control challenge is to balance the system power demands from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle. In the worst case scenario, only engine is used and hybrid system is completely disabled.
2013-09-24
Technical Paper
2013-01-2404
Mahendra Muli, Joe Cassar
It is not news anymore when somebody talks about increasing software content in today's vehicles, transportation systems and machinery. The software content and complexity has grown so tremendously and rapidly that even the most advanced product/software development techniques leave more to desire in view of evolving product life-cycles, feature content and need for development efficiency. Model-Based Design (MBD) techniques and V-Cycle based development processes address the significant need for managing complexity, and to some extent, efficiency in product development. Further efficiency in the development process can be achieved by enabling virtual validation of software components. The virtual validation environment for software not only has the ability to run the software component as a standalone unit for performance validation, but is also extended to the validation of the performance of the entire embedded software of an ECU, multiple ECUs and the entire system.
2004-10-26
Technical Paper
2004-01-2697
Leonard Kuo-Liang Shih, Tien-Chou Hsu
In the past decades, the diesel engines are considered as the major power source, not only because of their high thermal efficiency, high torque output, and easy maintenance; but also due to the improved exhaust emissions reduction technology. In order to increase the thermal efficiency, the low heat rejection ceramic coating engine is one of the possible solutions for future engine manufacturing. Due to the thermal insulating effects of the ceramic material (low thermal conductivity), the cylinder charge and engine components' temperatures are substantially increased. However, the thermal impact problem and the possible high friction characteristics of the new coating material can be deadly to the engine's lifetime. Various non-ceramic and ceramic materials are tested in this research to decide their thermal insulating effects on the engine performance and their downside on the friction and thermal impact problems.
2013-01-09
Technical Paper
2013-26-0044
Ashok Patidar, Umashanker Gupta, Nitin Marathe
Assessment of cooling performance in the design stage of vehicle allows a reduction in the number of needed prototypes and reduces the overall design cycle time. Frontend cooling and thermal management play an essential role in the early stages of commercial vehicle design. Sufficient airflow needs to be available for adequate cooling of the under-hood components. The amount of air mass flow depends on the under-hood geometry details, positioning and size of the grilles, fan operation and the positioning of the other components. Thermal performance depends on the selection of heat exchanger. This paper describes the effects of several design actions on engine cooling performance of a commercial vehicle with the help of Computational Fluid Dynamics (CFD) simulation tool Fluent™. Front of vehicle design is captured in detailed FE model, considering front bumper, grille, cabin, cargo and surrounding under-hood and underbody components.
2013-01-09
Technical Paper
2013-26-0126
Ashish Moholkar, Rizwan Khan, Jyotirmoy Barman, Sumit Arora
Increased options and flexibility in common rail direct injection provides a great opportunity for combustion optimization using fuel and air system with proper combustion chamber configuration. This paper elaborates the experimental work conducted for combustion optimization with combinations of piston bowl, intake port swirl, injector specifications and turbo charging on a 3.8 l four valve diesel engine of LDT application equipped with common rail fuel injection system and waste gate turbo charge. In meeting the target emission norms with internal engine measures, the design of the piston bowl and the nozzle configuration perform a defining role. Through simulations the best option had been carried out parametrically investigate the influence of piston bowl geometry and nozzle characteristics on the performance of the combustion system.
2013-01-09
Technical Paper
2013-26-0130
Antony Smith, Saurabh Rajauria, Sachin Agarwal
In the growing automobile world, every commercial vehicle manufacturer upgrades their product from their existing product to meet world market demand for high power engine with high torque, most fuel efficient, BS-IV and BS-V emission norms and less cost. In an Engine cylinder block and cylinder head are among the critical parts need to be modified to upgrade the existing engine platform. The VE4101 Engine is a massive 3.8 l 4 Cyl 16 valve engine based on the E483 4 cyl 8 valve engine, which is currently being mass produced in VECV, India. This engine cylinder block and cylinder head are designed with key features such as capable for high peak firing pressure, rigid load structure, curvy envelope and ribs to reduce NVH, light weight 2 split top box manufacturing method. Key strategy is used such as less capital investment in purchasing machines, no/less alteration in current machining and assembly line.
2013-10-07
Technical Paper
2013-36-0252
Sergio William Botero, Marcos Fernando Mendes de Brito, Rogério Nascimento de Carvalho, Antonio Carlos Scardini Villela, Tadeu Cavalcante Cordeiro de Melo
The development of new fuels involves several areas of an oil company and several tests, including vehicle emissions tests on chassis dynamometers and engine performance tests on engine bench laboratory. Particularly for diesel and blends of gasoline fuels, an important test is to evaluate the engine speed profile during the vehicle cold start. In this work, for engine speed profile analysis, it was developed a system to acquire data using the engine's flywheel ring gear information and the audio input of a standard notebook computer. It was also developed a specific software to analyze the acquired signals. The system is able to point out several important features of the engine start such as the starter motor beginning of operation, the maximum engine speed during the start time, the settling time and the engine idling speed. All of this information can be collected using a low cost set of instrumentation devices.
2013-10-07
Technical Paper
2013-36-0233
Matheus Ferreira, Mário Praça, Ricardo Simão
The increasing demand for engines with higher efficiency, reduced fuel consumption and high power density is driving the future engine technologies in the direction of downsizing and reduction of number of cylinders, especially for Otto engines. Specifically the Power Cell Unit (PCU) components are of extreme interest due to its potential for weight and friction reduction. To cope with these demands a new lightweight connecting rod design for flex fueled engines was developed. The combination of thinner web thickness and bushingless small end (coated and profiled), through the optimization by Finite Element Analysis (FEA) simulation, enabled on the new lightweight design a weight reduction of 25% maintaining safe connecting rod fatigue limits in a studied flex fueled engine. The connecting rod bearings were evaluated using Elasto-Hydrodynamic Lubrication (EHL) simulation, and demonstrated suitable results. The connecting rod material selected was the premium 46MnVS6 forged steel.
2013-10-07
Technical Paper
2013-36-0389
Tadeu Miguel Malagó de Amaral, Anton Zeller, Edson Valdomiro de Azevedo, Fernando Jun Yoshino, Gisela Ablas Marques, Johnny Ossami Kagawa, Marcos Jose Dantas de Oliveira
Air cleaners are used in a wide range of automotive applications. From passenger cars to heavy duty trucks, there is always an air cleaner to keep inlet air free of impurities and air flow passage obstruction in low levels. Today's automotive air intake systems are developed to deliver maximum filtration efficiency, maximum dust holding capacity and maximum service interval range based on engine performance and reliability requirements [1]. In Brazil, some applications require outstanding performance for the air cleaners. One of them is at harvester application. In this case, vehicles are exposed to thin soil particles in high quantities due to harvester movement at plantation work. At the same time, engine performance needs to be kept during long journeys. According to this limitation, re-fuelling and components replacements are done direct at field. Any vehicle stop means lower productivity and more costs.
2013-10-07
Technical Paper
2013-36-0375
Marcos N. Schiesari, Vinícius Abrão S. Marques
Turbochargers are used in a wide range of applications, duty cycles and different vehicle usage rates in whole world. As known, the exhaust gas temperature is still a challenge to the turbochargers manufactures once it has a considerable impact in the turbocharger durability and reliability. High temperatures can lead to thermal mechanical stress, which can cause material fatigue. Extensive works have been carried out by product and combustion engineers to guarantee that temperature limits are under acceptable values. However, there are other factors that are related to the application usage in the field that can contribute to the exhaust gas temperature increase. As known, service engineers have the difficult task of identifying the reason why some components used for years in different localities fail only in certain regions, fleet or applications. Trouble shootings are often a useful guide in the investigation, but are to generic most of the cases.
2013-10-07
Technical Paper
2013-36-0312
I. Coutinho, A. Pereira, C. Sanches, M. Mottin
The internal combustion engine air intake manifold is subjected to continuous dynamic excitation due to unbalanced firing sequence and alternated movement of the pistons. An elastic anchoring for the intake manifold of Iveco's new bus was developed based on two criteria: 1. increase the natural frequency of the system to avoid coupling with engine's NEF 6 idle input and 2. minimize the vibration transmitted to the chassis. In order to solve this duality an optimization algorithm was used to fit cushion stiffness to both requirements. The system behavior is evaluated virtually in frequency domain through FRFs and its modal mode shapes and natural frequencies (eigenvectors and eigenvalues) extracted with Lanczos method.
2013-10-07
Technical Paper
2013-36-0595
Wiliam Tean Su
In the past few years, Finite Element Analysis (FEA) has become an almost essential engineering tool in product development. In addition to that, structural optimization, which is almost as old as the finite element method, is a widely used tool in engineering product design definition. One vastly used method is the shape optimization, which has as an objective the minimization of stress concentration on determined regions. In this work, a 6 cylinder diesel engine crankshaft was analyzed and a structural optimization was performed, more specifically at the web region. The interpretation of the shape optimization results led to a slightly modified geometry of the crankshaft, with the mass of the crankshaft throw only 0.5% higher than the original model. Also, the fatigue safety factor evaluation was performed for both reference and optimized crankshafts as a comparison criterion. The same boundary condition used in the shape optimization was employed for the fatigue factor evaluation.
2013-10-07
Technical Paper
2013-36-0605
Fabio B. Bassetti
Modern diesel engines for vehicular applications such as buses and other commercial vehicles are increasingly using technological resources in order to meet the pollutant emissions regulations. Among these features, the turbocharger fulfills an essential function of providing a higher air flow to the engine intake, providing a cleaner and more efficient combustion. During the application process of a turbocharger, calculations are performed to estimate the life of the compressor impeller, which takes into account the maximum shaft speed and the number of cycles that cause fatigue damage. Among these parameters, the maximum speed affects directly in the fatigue life of the impeller. Due to the different material options for the compressor impeller, the mass properties of each type of rotor may result in differences in their inertias thus impacting the maximum speed and the fatigue life calculation.
2013-10-07
Technical Paper
2013-36-0562
T. A. A. Moreira, F. A. Rodrigues Filho, L.A.R. Gonçalves, J. E. M Barros, F. J. P. Pujatti, R. M Valle
It developed a design and construction methodology of a stratified charge torch ignition system for an Otto engine aiming fuel consumption and pollutant emission reduction. The torch ignition system is made of a combustion pre-chamber equipped with a direct fuel injector, an air injector and a spark plug. Fuel is directly injected in the pre-chamber aiming the formation of a lightly rich air fuel mixture. The combustion process starts in the pre-chamber and as the pressure rises, combustion jet flames are produced through interconnection nozzles into the main chamber. The high thermal energy of the jet flames reduces the combustion time, increases the combustion efficiency and allows the engine to efficiently burn lean air fuel mixture of several kinds of fuel in the main chamber, even those that are difficult to ignite. After the combustion takes place in the pre-chamber, air is also injected to help the exhaust process of the combustion products of the previous cycle.
2013-09-08
Technical Paper
2013-24-0093
Riccardo Rossi, Ettore Musu, Stefano Frigo, Roberto Gentili, Rolf D. Reitz
Due to concerns regarding pollutant and CO2 emissions, advanced combustion modes that can simultaneously reduce exhaust emissions and improve thermal efficiency have been widely investigated. The main characteristic of the new combustion strategies, such as HCCI and LTC, is that the formation of a homogenous mixture or a controllable stratified mixture is required prior to ignition. The major issue with these approaches is the lack of a direct method for the control of ignition timing and combustion rate, which can be only indirectly controlled using high EGR rates and/or lean mixtures. Homogeneous Charge Progressive Combustion (HCPC) is based on the split-cycle principle. Intake and compression phases are performed in a reciprocating external compressor, which drives the air into the combustor cylinder during the combustion process, through a transfer duct. A transfer valve is positioned between the compressor cylinder and the transfer duct.
2011-08-30
Technical Paper
2011-01-1964
Toru Miyamoto, Hirokazu Hasegawa, Takashi Yagenji, Takehiko Seo, Masato Mikami, Hajime Kabashima, Tomoyuki Hashimoto
The present study experimentally investigated cyclic variation of combustion characteristics of a diesel engine with hydrogen added to the intake air in detail. As the result, there were three ignition modes: (1) hydrogen ignition mode, (2) hydrogen-assisted ignition mode, and (3) diesel-fuel ignition mode. Ignition timing fluctuated from cycle to cycle in each ignition mode and between one ignition mode and another mode. As the coolant temperature was increased, the number of cycles in diesel-fuel ignition mode decreased, and indicated thermal efficiency and cyclic variation was improved. In the case with the blow-by gas introduced to intake port, preflame reaction of blow-by gas first occurred, ignited hydrogen, and then diesel-fuel was ignited by hydrogen combustion in hydrogen ignition mode and hydrogen-assisted ignition mode.
2011-08-30
Technical Paper
2011-01-2022
Mehrzad Kaiadi, Per Tunestal, Bengt Johansson
Abstract Stoichiometric operation of Spark Ignited (SI) Heavy Duty Natural Gas (HDNG) engines with a three way catalyst results in very low emissions however they suffer from bad gas-exchange efficiency due to use of throttle which results in high throttling losses. Variable Geometry Turbine (VGT) is a good practice to reduce throttling losses in a certain operating region of the engine. VTG technology is extensively used in diesel engines; it is very much ignored in gasoline engines however it is possible and advantageous to be used on HDNG engine due to their relatively low exhaust gas temperature. Exhaust gas temperatures in HDNG engines are low enough (lower than 760 degree Celsius) and tolerable for VGT material. Traditionally HDNG are equipped with a turbocharger with waste-gate but it is easy and simple to replace the by-pass turbocharger with a well-matched VGT.
2011-09-13
Technical Paper
2011-01-2285
Lisa Larsson, Lennart Löfdahl, Erik Dahl, Torbjörn Wiklund
This investigation is a continuing analysis of the cooling performance and aerodynamic properties of a rear-mounted cooling module on a semi-generic commercial vehicle, which was carried out by Larsson, Löfdahl and Wiklund. In the previous study two designs of the cooling package installation were positioned behind the rear wheelhouse and the results were compared to a front-mounted cooling module. The investigation was mainly focused on a critical cooling situation occurring at lower vehicle speeds for a local distribution vehicle. The conclusion from the study was that the cooling performance for one of the rear-mounted installation was favorable compared to the front-mounted cooling package. This was mainly due to the low vehicle speed, the high fan speed and to fewer obstacles around the cooling module resulting in a lower system restriction within the installation.
2011-09-13
Technical Paper
2011-01-2233
Anandan Sivakumar, Raghvendra Gopal
Diesel engine fuel hose return line is considered as a low pressure line and consists of two layers. The inner layer is used to carry the excess fuel, thereby hose material shall have resistance to fuel and its residues. The outer layer is used to protect inner layer from heat, ozone and oil spillage, thereby outer cover material shall have resistance against the heat, ozone and engine oil. Currently NBR PVC, NBR and FKM materials have been used as inner layer materials in diesel engine fuel hose outer cover application, according to service temperature. Halogen contained CSM material has been used for outer cover application and the production of CSM material was withdrawn by one of the major manufacturer recently. Current global challenge is to use environment friendly material in vehicle components to make hazardous free environment. To replace CSM material, which contains Halogen, the available options are CPE, CR, HNBR and AEM materials.
2011-09-13
Technical Paper
2011-01-2231
Khalil Dilawar Nadaf, Milind V. Kulkarni, Vijay M. Mahangade, Dr.(Prof.) S. G. Joshi
The conventional methods of connecting rod design consider the centre of gravity (CG) position at 2/3rd distance from connecting rod small end. The connecting rod CG position decides the reciprocating and rotating mass distribution. The reciprocating force impacts inertia stresses at the connecting rod small end while rotating force impacts the inertial stresses, minimum oil film thickness (MOFT) and peak oil film pressure (POFP) at the connecting rod big end. This paper work has analyzed connecting rod design in view of three probable causes of CG position variation as due to dimensional changes to sustain higher loading, manufacturing process variation and high speed of turbocharged (TC) engine. Total nine load cases have been considered for study of these causes. As well, CG variation impact is analyzed at big end bearings for MOFT and POFP.
2011-09-13
Journal Article
2011-01-2232
Marc Megel, Barry Westmoreland, Guy Jones, Ford Phillips, Douglas Eberle, Mark Tussing, NIgel Yeomans
Historically, heavy-duty diesel (HDD) engine designs have evolved along the path of increased power output, improved fuel efficiency and reduced exhaust gas emissions, driven both by regulatory and market requirements. The various technologies employed to achieve this evolution have resulted in ever-increasing engine operating cylinder pressures, higher than for any other class of internal combustion engine. Traditional HDD engine design architecture limits peak cylinder pressure (PCP) to about 200 bar (2900 psi). HDD PCP had steadily increased from the early 1970's until the mid 2000's, at which point the structural limit was reached using traditional methods and materials. Specific power output reversed its historical trend and fell at this time as a result of technologies employed to satisfy new emissions requirements, most notably exhaust gas recirculation (EGR).
2011-09-13
Technical Paper
2011-01-2230
Zhiyong Zhang
In this study, a measurement system is developed for obtaining continuous piston temperatures in a working engine by using a voltage recorder. The developed system has a very high accuracy with a measurement error within ± 1 °C. Since there is no relative movement between the measurement system and the piston, its reliability significantly increases. In order to test its accuracy and reliability, the developed measurement system is used to obtain the piston temperatures under various operating conditions with different air-fuel ratios, oil temperatures, and engine speeds. The measurement results are then used to calibrate the piston temperature field simulated by numerical analysis.
2011-09-13
Technical Paper
2011-01-2191
Alberto Boretti, Houshsng Masudi, Joseph Scalzo
The introduction of advanced internal combustion engine mechanisms and powertrains may improve the fuel conversion efficiency of an engine and thus reduce the amount of energy needed to power the vehicle. The paper presents a novel design of a variable compression ratio advanced spark ignition engine that also permits an expansion ratio that may differ from the induction stroke therefore generating an Atkinson cycle effect. The stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. The variable ratio of maximum to minimum in-cylinder volumes also improves the full load power output of the engine. Results of vehicle driving cycle simulations of a light-duty gasoline vehicle with the advanced engine show dramatic improvements of fuel economy.
2011-09-13
Technical Paper
2011-01-2182
Peter Gullberg, Lennart Lofdahl, Peter Nilsson
Today CFD is an important tool for engineers in the automotive industry who model and simulate fluid flow. For the complex field of Underhood Thermal Management, CFD has become a very important tool to engineer the cooling airflow process in the engine bay of vehicles. To model the cooling airflow process accurately in CFD, it is of utmost importance to model all components in the cooling airflow path accurately. These components are the heat exchangers, fan and engine bay blockage effect. This paper presents CFD simulations together with correlating measurements of a cooling airflow system placed in a test rig. The system contains a heavy duty truck louvered fin radiator core, fan shroud, fan ring and fan. Behind the cooling module and fan, a 1D engine silhouette is placed to mimic the blockage done by a truck engine. Furthermore, a simple hood is mounted over the module to mimic the guiding of air done by the hood shape in an engine bay.
2011-09-13
Technical Paper
2011-01-2184
Asma Al Tamimi, Mohammad Salah, Ahmad Al-Jarrah PhD
Advanced vehicular thermal management system can improve engine performance, minimize fuel consumption, and reduce emissions by harmoniously operating computer-controlled servomotor components. In this paper, a neural network-based optimal control strategy is proposed to regulate the engine temperature through the advanced cooling system. The proposed optimization algorithm introduces a cost function of a predefined temperature error and a control input that is developed to minimize the introduced cost function. The main objective of the proposed optimal control design is to minimize the temperature error and power consumption of the system actuators. The development of the optimal controller utilizes a multi-layer neural network to approximate the proposed cost function. A representative numerical simulation is introduced in this paper to demonstrate the performance of the developed optimal controller.
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