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Viewing 1 to 30 of 17835
2014-11-11
Technical Paper
2014-32-0026
Alessandro Franceschini, Emanuele Pellegrini, Raffaele Squarcini
Nowadays the challenge in design auxiliary device for automotive small engine is focused on the packaging reduction and on the increase of the performances. This requirements are in contrast to each other and in order to fulfil the project specifications, new and more refined design tools and procedures need to be developed. This paper presents a calculation loop developed by Pierburg Pump Technology Italy S.p.a. (PPT). It supports the design of a variable displacement oil pump component for engine applications. The work is focused on the fatigue life evaluation of a joint, which transmits the drive torque from the engine to the oil pump. The aim of the procedure is to calculate the onset of the surface fatigue phenomenon in the hexagonal joint which drives the oil pump, taking into account the axes misalignment and the flat to flat clearance. The study has involved several matters, experimental measures, CFD, MBA and FEM analyses. A calculation procedure has been set up in order to consider all the necessary loads applied on the joint.
2014-11-11
Technical Paper
2014-32-0017
R Varunprabhu, Himadri Bushan Das, S Jabez Dhinagar
The steering system of a 3-wheeler vehicle comprises a single column steering tube. The steering inclination at handle bar end is converted to wheel slip or inclination by the steering column. A compromise in either ride or handling is considered in the functional requirement of the 3-wheeler vehicle. The three wheeled vehicle under study is designed for ride comfort and the handling levels are compromised. Variants of the vehicle under study are meant for public passenger transport requirements. Drivers’ ride comfort is considered as the primary functional requirement during design and driver’s steering fatigue is not given importance. For the comfort of driver, steering effort has to be less without compromise in handling characteristics. The driver of this type of vehicle drives the vehicle for 15-18 hours a day. Driver’s feedback suggests high steering effort as a human fatigue failure mode and also a cause of shoulder pain. In this project, a DC motor assisted steering mechanism with an electronic control module has been designed.
2014-11-11
Technical Paper
2014-32-0023
Daniele Barbani, Niccolò Baldanzini, Marco Pierini
Motorcycle accidents are a serious road safety issue in the European Union (EU). Several projects to increase motorcycle safety were funded by the EU within the FP7 (Seventh Frame Program). Many others are likely to be funded within H2020 (Horizon 2020) as well as by national projects of each member state. In this context, numerical simulations play a strategic role since they can be a powerful tool to simplify, assist and speed up the work of the engineers. During the last years, the authors have presented the development and validation of FE models for complete crash test scenarios (i.e. motorcycle with an anthropometric test dummy that impacts against a car) and their use to evaluate head and neck injuries. During the validation phase the authors observed some variability in the results. While variability of the input parameters is a fact in real world crash test, the extent of the variability in the results has to be estimated and assessed in order to improve the design process of safety devices.
2014-11-11
Technical Paper
2014-32-0022
Federico Giovannini, Niccolò Baldanzini, Marco Pierini
The Powered Two-Wheelers (PTWs) control is more complex than any other road vehicle control, due to the implicit instability of those vehicles. Maneuvers such as braking or swerving, require additional driving abilities to prevent the vehicle from falling, in particular during emergency events, such as panic braking or last second swerving. Focusing on emergency braking maneuvers, in those situations the PTW control is very demanding due to the necessity to adjust the braking intensity in the best way. For standard PTWs, a common cause of accident is the loss of adherence and the consequent loss of stability due to emergency braking manoeuvers. It is worth noting that, for a PTW, the loss of stability means a high probability of fall, especially while cornering. Accordingly, the aim of this study is to propose and evaluate a fall detection algorithm for PTWs performing braking manoeuvers, developed to alert an advanced riding assistance system in order to produce proper counteractions against the imminent fall.
2014-11-11
Technical Paper
2014-32-0028
T Manikandan, S Sarmadh Ameer, A Sivakumar, Davinder Kumar, R Venkatesan, VenkataKalyana Kumar
The proposed paper is on advanced vehicle information panel which shall display instant mileage zone in which the user is operating with inputs from engine crank sensor and vehicle speed sensor alone. And moreover, gear assistance and throttle assistance through visuals is provided. Mileage data for different engine loading at different Speeds is pre-calculated at standard conditions and fed into a micro-controller. In real time, the engine loading, by means of intelligent software, is sensed by engine crank sensor and based on the pre-fed value, the mileage zone of the vehicle at that particular instant is to be displayed using an information panel. Based on the relation between speed sensor and engine crank sensor when the vehicle is running, the gear in which the vehicle is running is to be calculated. For a vehicle running in a certain gear and in certain speed, the ideal engine loading and mileage zone is predefined. So when the user is riding in a certain gear with certain engine load, the micro controller compares that with the programmed data which is the ideal condition data, and assists the user, in case the rider is not riding the vehicle as per the ideal data, by gear up/down prompt or throttle up/down prompt by means of the said information panel.
2014-11-11
Technical Paper
2014-32-0027
T Manikandan, S Sarmadh Ameer, A Sivakumar, Samaraj Dhinagar
The proposed paper is on electrical energy conservation in a two wheeler. Electrical energy generation adds a maximum of 10% excess load torque on an engine and hence saving electrical energy would ultimately reduce the consumption of fuel. Load Control Module is a single intelligent device which is placed in between electrical energy generation and consumption. The Module controls and distributes energy to the corresponding loads depending on parameters like battery voltage, engine RPM, overhead light illumination levels and load usage time. The Module prioritizes battery charging for maintaining the life of the battery. The Module has a microcontroller and it is programmed with algorithm for prioritization and energy distribution with respect to input conditions. A vehicle fitted with the Load Control Module was tested in city driving cycle (CDC) condition as per ARAI (Automotive Research Association of India) standard and it was found that the electrical loading decreased to about 30% when compared to vehicle with uncontrolled loading.
2014-11-11
Technical Paper
2014-32-0025
Maki Kawakoshi, Takashi Kobayashi, Makoto Hasegawa
Controllability (C) is the parameter that determines the Automotive Safety Integrity Level (ASIL) of each hazardous event based on an international standard of electrical and/or electronic systems within road vehicles (ISO 26262). On application to motorcycles of ISO26262 that was intended only for passenger cars, it is considered that it is desirable to estimate the C class by subjective evaluation of expert riders. Expert riders are professional test riders, and they differ from ordinary riders. They can ride safely and evaluate the motorcycle performance stably even if the test condition is at the limit of vehicle performance. Expert riders evaluate motorcycle performance from the viewpoint of ordinary riders. However, riding maneuvers of ordinary riders have not been confirmed by objective data. For this reason, it is important to understand the basic characteristics of riding maneuvers of expert riders and of ordinary riders. This study seeks to confirm the compatibility between the riding maneuvers of expert riders and those of ordinary riders.
2014-11-11
Technical Paper
2014-32-0088
Claudio Annicchiarico, Renzo Capitani
Abstract In a Formula SAE car, as for almost all racecars, suppressing or limiting the action of the differential mechanism is the technique mostly adopted to improve the traction exiting the high lateral acceleration corners. The common Limited Slip Differentials (LSDs) unbalance the traction torque distribution, generating as a secondary effect a yaw torque on the vehicle. If this feature is electronically controlled, these devices can be used to manage the attitude of the car. The yaw torque introduced by an electronically controlled LSD (which can also be called SAD, “Semi-Active Differential”) could suddenly change from oversteering (i.e. pro-yaw) to understeering (i.e. anti-yaw), depending on the driving conditions. Therefore, controlling the vehicle attitude with a SAD could be challenging, and its effectiveness could be low if compared with the common torque vectoring systems, which act on the brake system of the car. In addition, unlike common ESC (“Electronic Stability Control”) systems do, a SAD can modify the vehicle attitude without limiting its traction performance, which is a crucial factor for racecars.
2014-11-11
Technical Paper
2014-32-0090
Jeffrey Blair, Glenn Bower
Abstract Operation of snowmobiles in national parks is restricted to vehicles meeting the Best Available Technology standard for exhaust and noise emissions as established by the National Parks Service. An engine exceeding these standards while operating on a blend of gasoline and bio-isobutanol has been developed based on a production four-stroke snowmobile engine. Miller cycle operation was achieved via late intake valve closing and turbocharging. The production Rotax ACE 600cc 2 cylinder engine was modeled using Ricardo WAVE. After this model was validated with physical testing, different valve lift profiles were evaluated for brake specific fuel consumption and brake power. The results from this analysis were used to determine a camshaft profile for Miller cycle operation. This was done to reduce part load pumping losses and increase engine efficiency while maintaining production power density. A catalytic converter was added to reduce exhaust gas emissions, as measured by the EPA 40 CFR Part 1051 5-mode emissions test cycle.
2014-11-11
Technical Paper
2014-32-0008
Stefan Krimplstätter, Franz Winkler, Roland Oswald, Roland Kirchberger
Abstract The Institute for Internal Combustion Engines and Thermodynamics, Graz University of Technology, has presented several applications of its 2-stroke LPDI (low pressure direct injection) technology in the previous years ([1], [2], [3]). In order to improve the competitiveness of the 2-stroke LPDI technology, an air cooled 50cm3 scooter application has been developed. All previous applications have been liquid cooled. This air cooled application demonstrates the EURO 4 (2017) ability of the technology and shows that the 2S-LPDI technology can also be applied to low cost air-cooled engines. Hence, the complete scooter and moped fleet can be equipped with this technology in order to fulfil both the emission standards and the COP (conformity of production) requirements of Euro 4 emission stage. The paper presents the Euro 4 Scooter results and describes the efficient conversion process of the existing carburetor engine to the LPDI version. Euro 4 results can be achieved with conventional exhaust system architecture known from the present Euro 2 applications.
2014-11-11
Technical Paper
2014-32-0014
Hans-Juergen Schacht, Manuel Leibetseder, Niko Bretterklieber, Stephan Schmidt, Roland Kirchberger
Abstract Due to the small number of two wheelers in Europe and their seasonal use, their contribution to the total emissions has been underestimated for a long time. With the implementation of the new emission regulation 168/2013 [3] for type approval coming into force 2016, the two wheeler sector is facing major changes. The need to fulfil more stringent emission limits and the high demand on the durability of after treatment systems result in an engine control system that is getting more complex and therewith more expensive. Especially the low cost two wheelers with small engine capacities will be affected by increasing costs which cannot be covered by the actual competitive product price. Therefore, new vehicle concepts have to be introduced on the market. A vehicle concept of a plug in hybrid electric city scooter with range extender as well as the range extender itself have already been published in SAE Papers 2011-32-0592 [1] and 2012-32-0083 [2]. The low cost range extender is composed of a simple, throttle-less operated, port controlled two stroke engine and an externally controlled generator.
2014-11-11
Technical Paper
2014-32-0016
Sei Takahashi, Hideo Nakamura, Makoto Hasegawa
Abstract ISO 26262 (Road vehicles - Functional safety), a functional safety standard for motor vehicles, was published in November 2011. In this standard, hazardous events associated with each item constituting a safety-related system are assessed according to three criteria, namely, Severity, Exposure, and Controllability, thereby determining ASILs (Automotive Safety Integrity Levels) representing safety levels for motor vehicles. Although motorcycles are not included in the scope of application of the current edition of ISO 26262, it is expected that motorcycles will be included in the next revision. However, it is not appropriate to directly apply ASILs to motorcycles. In the first place, the situation of usage in practice presumably differs between motorcycles and motor vehicles. Accordingly, in this research, we attempted to newly define Motorcycle Safety Integrity Levels (MSILs). We demonstrate in this article that it is to reduce the maximum severity in the Correspondence Diagram between Risk and ASIL (CDRA) and to increase the degree of acceptable risks in view of situations specific to motorcycles.
2014-11-11
Technical Paper
2014-32-0040
John Walters, Francois Brun
Abstract Stringent emissions legislation is being applied to small motorcycles and scooters around the world. This is forcing, gradually, the replacement of carburetors by electronic fuel injection (EFI) systems. The integration of this new technology creates new constraints on the engine and also on the vehicle. This study will provide an overview of these constraints and also technical solutions to reduce the impact on engine and vehicle. A special focus will be done on the fuel system, where the development of an advanced technology will be discussed in detail. This technology marks a break with the standard automotive fuel system architecture in order to fulfill the specific requirements of scooters and small motorcycles: low size, low weight, low energy demand, as well as simple integration. The discussion will disclose: the advantages and drawbacks of different fuel system architectures, the detailed description of the technology selected to achieve the requirements, the modelling approach used for the sizing and optimization of the design, and finally the performance achieved on the test bench.
2014-11-11
Technical Paper
2014-32-0021
Kazuhiro Ito, Yoshitaka Tezuka, Atsushi Hoshino, Keita Sakurada
Abstract In this study, we developed a simulation method for rough road running condition to reproduce the behaviors of a vehicle body and to precisely estimate the input loads to the frame. We designed the simulation method focusing on a front fork model and a rider model optimized for this type of analysis. In the suspension model development, we conducted detailed measurement of the suspension characteristics on a test bench. Based on the yielded results, the friction force, as well as the spring reaction force and the damping force, was reproduced in the suspension model. The friction of the suspension varies depending on the magnitude of the reaction force associated with bending and this effect was also implemented in the model. Regarding the rider model, the actual behavior of a rider was investigated through the recorded motion video data and used to define the necessary degrees of freedom. Based on this investigation, the degree of freedom of three, i.e. vertical, longitudinal and forward leaning motions, was adopted to the rider model.
2014-11-11
Technical Paper
2014-32-0020
Patrick Falk, Christian Hubmann
Abstract Originally developed for the automotive market, a fully automatic real-time measurement tool AVL-DRIVE is commercially available for analyzing and scoring vehicle drive quality, also known as “Driveability”. This system from AVL uses its own transducers, calibrated to the sensitivity and response of the human body to measure the forces felt by the driver, such as acceleration, shock, surging, vibration, noise, etc. Simultaneously, the vehicle operating conditions are measured, (throttle grip angle, engine speed, gear, vehicle speed, temperature, etc.). Because the software is pre-programmed with the scores from a multitude of different vehicles in each vehicle class via neural networks and fuzzy logic formula, a quality score with reference to similar competitor vehicles is instantly given. This tool is already successfully implemented in the market for years to investigate such driveability parameters for passenger cars. Due to the fact that electronic systems more and more find their way into the 2-wheeler applications, motorcycle manufacturers are facing a lot of challenges and these are increasing from year to year.
2014-11-11
Technical Paper
2014-32-0018
Kenichi Morimoto, Kenichi Tanaka
Abstract There have been a number of attempts to clarify the relationship between motorcycle specifications and shimmy phenomenon. Some of such efforts are based on equations of motion. The methods used in those efforts are suitable for analyzing motions in a fundamental structure. However, when the degree of freedom is large, it is extremely difficult to deliver an equation of motion. Therefore, a practical method cannot be found generally when applying the methods employing equations of motion. We also conducted the analysis of shimmy using multi-body dynamics simulation. The yielded results were useful only for clarifying the differences in shimmy levels among motorcycles. However, they were not helpful to understand the relationships between specifications and shimmy phenomenon. In this study, we focused clarifying these relationships and we took four study steps shown below: 1 Narrowing down the motorcycle specifications affecting shimmy2 Determining physical parameters influential to shimmy3 Investigating how a change of physical parameters affects shimmy using simplified model4 Analyzing how the changes of motorcycle specifications affect the shimmy Following these steps, we clarified the relationships between motorcycle's specifications and shimmy by using only three physical parameters.
2014-11-11
Technical Paper
2014-32-0055
Francesco Maiani, Alessio Sisi, Walther Leardini
Abstract In recent years the 2-wheelers engines companies have been focused on increasing the overall engine efficiency, that can be achieved amongst other by engine down-speeding, engine down-sizing and by reducing the frictions; however, to maintain or improve vehicle performance, it is necessary to provide a corresponding increase in specific power. In accordance with these trends, the studied approaches and methodologies have been exploited, during the development of the new Piaggio small scooter engine. In this work a multi-objective analysis has been applied to the valve train system design, in order to optimize the engine performance in terms of friction reduction, power curve and timing system response. Along with this optimization methodology, a robust design has been studied to make the peak cranking compression pressure insensitive to the engine starting device working. These calculation methodologies have been followed using commercial software as GT-SUITE® code and the modeFRONTIER® platform for the multi-objective optimization analysis.
2014-11-11
Technical Paper
2014-32-0044
Simone Vezzù, Carlo Cavallini, Silvano Rech, Enrico Vedelago, Alessandro Giorgetti
Abstract The deposition of thick, pore-free, high-performance copper alloy matrix composite coatings is a topic of interest for several industrial applications, including friction materials, high-strength electrical contacts, and welding electrodes, among others. This study investigates the use of cold spray to deposit CuCrZr/Al2O3 cermet coatings on aluminum alloy 6060. The objective is to integrate copper-based materials with aluminum-based materials, ensuring a high degree of mechanical and thermal contact, using a low temperature process that does not adversely affect the properties of the base materials. This technique can be used to produce integral coolers and aluminum-based bearings for automotive and motorcycle applications. Fused and crushed alumina and gas-atomized CuCrZr powder blends have been used as initial feedstocks, with compositional weight ratios of 65/35 and 80/20 (ceramic/metal). The coatings have been characterized in terms of microstructure and morphology, coating microindentation hardness, cohesion strength, and adhesion strength to the aluminum alloy substrate.
2014-11-11
Technical Paper
2014-32-0067
Henning Heikes, Christian Steinbrecher, Bastian Reineke, Jürgen Berkemer, Thorsten Raatz, Wolfgang Fischer
Abstract Cost reduction of engine management systems (EMS) for two-wheeler applications is the key to utilize their potentials compared to carburetor bikes regarding emissions, fuel economy and system robustness. In order to reduce the costs of a system with port fuel injection (PFI) Bosch is developing an EMS without a manifold air pressure (MAP) sensor. The pressure sensor is usually used to compensate for different influences on the air mass, which cannot be detected via the throttle position sensor (TPS) and mean engine speed. Such influences are different leakage rates of the throttle body and changing ambient conditions like air pressure. Bosch has shown in the past that a virtual sensor relying on model based evaluation of engine speed can be used for a detection of leakage air mass in idling to improve the pre-control of the air-fuel ratio. This provides a functionality which so far was only possible with an intake pressure sensor. In this paper the air mass calculated from the model based engine speed evaluation is used to adapt the influence of ambient pressure changes e.g. because of different altitudes.
2014-11-11
Technical Paper
2014-32-0061
Rama Subbu, Baskar Anthony Samy, Piyush Mani Sharma, Prasanna Mahendiran
Abstract Ride comfort, driving stability and drivability are vital factors in terms of vehicle performance and customer satisfaction. Crankshaft unbalance is a source for the vibration that reduces the vehicle performance and it needs to be controlled to some extent such that the vehicle performance will be improved. The IC engine is made up of reciprocating and rotating parts. They produce unbalance forces during their operation and produces vibration in Vehicle. The vibration reduction will be possible by minimizing these unbalance forces and by optimizing the crankshaft of the two wheeled vehicle engine design. Many researches were made to find the causes for the vibration and to reduce it. But still there is a research gap on the testing and simulation of engine components (crankshaft, connecting rod and piston assembly). In this study, an attempt is made to represent the engine vibrations and its isolation to provide a gate way for the future work on it. This study shows the various steps carried out on the multibody modeling of the IC engine components including engine crankshaft and their orientations.
2014-11-11
Technical Paper
2014-32-0069
Ken Fosaaen
Abstract Global concerns over pollution have led to increasingly strict emissions legislation targeting small engines, which currently pollute at a much greater level than modern multi-cylinder automotive engines. Closed-loop control may be required to meet many future legislation requirements; however, such systems can be impractical due to high added component costs. A necessary component for closed-loop engine control is an oxygen sensor. Existing automotive oxygen sensors are too large, require too much power, and are far too expensive to be suitable for the vast majority of the global small engine applications; therefore, some manufacturers have developed smaller and/or unheated versions based on their existing sensors to meet this emerging need. The ability to miniaturize resistive based sensors well below that of traditional Nernst (zirconia based) oxygen sensors affords the opportunity to meet future emissions standards with less of an impact on cost. The performance of a novel low-cost, low-power, narrow-band resistive-based oxygen sensor was compared with the stock oxygen sensor and several other commercially available oxygen sensors on a 2014 Honda Grom 125E motorcycle.
2014-11-11
Technical Paper
2014-32-0076
Christian Steinbrecher, Bastian Reineke, Wolfgang Fischer, Henning Heikes, Thorsten Raatz
Abstract Equipping low cost two-wheelers with engine management systems (EMS) enables not only a reduction of emissions but also an improvement in fuel consumption and system robustness. These benefits are accompanied by initially higher system costs compared to carburetor systems. Therefore, intelligent software solutions are developed by Bosch, which enable a reduction of the necessary sensors for a port fuel injection system (PFI) and furthermore provide new possibilities for combustion control. One example for these intelligent software solutions is a model based evaluation of the engine speed. By use of the information contained in the engine speed signal, characteristic features like air charge, indicated mean effective pressure (imep) and combustion phasing are derivable. The present paper illustrates how these features could be used to reduce the system costs and to improve fuel consumption and system robustness. Especially in the low cost segment there are significant bike-to-bike variations e.g. compression ratio or valve timing deviations.
2014-11-11
Technical Paper
2014-32-0136
Thomas Metzinger, Christoph Raber, Christoph Wittmann
Abstract This paper discusses the design elements for a wet clutch system to successfully meet the requirements of today's motorcycle market. You can find new design ideas regarding how to realize important and critical clutch performance features such as torque boost, coast torque reduction (anti-hopping function), reduced actuation force, reduced drag torque, optimized weight, and/or optimized product cost. Most of these functions and features can be implemented in a modular clutch kit in which many of the parameters can be adapted with a minor design change of just a few components.
2014-11-11
Technical Paper
2014-32-0107
Takahiro Masuda, Kouji Sakai, Yuki Yamaguchi, Jun-ichi Kaku, Hirobumi Nagasaka
Abstract This paper proposes a novel engine starter system composed of a small-power electric motor and a simple mechanical valve train. The system makes it possible to design more efficient starters than conventional systems, and it is especially effective to restart engines equipped with idling stop systems. Recently, several idling stop systems, having intelligent start-up functions and highly-efficient generate capabilities have been proposed for motorcycles. One of challenges of the idling stop systems is the downsizing of electric motors for starting-up. However, there are many limitations to downsize the electric motors in the conventional idling stop systems, since the systems utilize the forward-rotational torque of the electric motors to compress the air-fuel mixture gas in the cylinders. Our studies exceeded the limitations of downsizing the electric motors by mainly using the engine combustion energy instead of the electric energy to go over the first compression top dead center.
2014-11-11
Technical Paper
2014-32-0053
Yoshihiro Nakagawa, Shinya Takahashi, Mikihito Masaki, Ranju Imao
Abstract In brake squeal analyses using FE models, minimizing the discrepancies in vibration characteristics between the measurement and the simulation is a key issue for improving its reproducibility. The discrepancies are generally adjusted by the shape parameters and/or material properties applied to the model. However, the discrepancy cannot be easily adjusted, especially, for the vibration characteristic of the disc model of a motorcycle. One of the factors that give a large impact on this discrepancy is a thermal history of the disc. That thermal history includes the one experienced in manufacturing process. In this paper, we examine the effects of residual stress on the natural frequency of motorcycle discs. The residual stress on the disc surface was measured by X-ray stress measurement method. It was followed by an eigenvalue analysis. In this analysis, we developed a unique method in which the residual stress was substituted by thermal stress. Using this method, the discrepancy between measurement and calculation of the natural frequency was reduced from ±5.2% to ±1.3%.
2014-10-13
Technical Paper
2014-01-2578
Konrad Pietrykowski
Abstract The article presents the simulation results of the combustion process made based on a 3D-CFD mathematical model of the aircraft radial engine. The object of research was the 9-cylinder aircraft engine ASZ-62IR. The model comprised of the internal geometry of the cylinder and pipes in the cylinder head together with the inlet pipe. The model has been verified on the base of the pressure characteristics in the inlet pipe obtained from the experiment. In order to reproduce the same process of mixture formation as in the real engine, the model involved the process of induction, compression and combustion. The conducted research was aimed at verifying the influence of switching off one of the spark plugs on the combustion process. The simulation was done for three versions of ignition, for two spark plugs at the same time, only the front spark plug, only the rear spark plug. The research has been conducted in the conditions of maximum constant power of engine that is 686 kW. As a result of the conducted research, the reaction progress variables in the combustion chamber representing the spread of flame and rate of heat release have been obtained.
2014-10-13
Technical Paper
2014-01-2709
Xianjing Li, Liguang Li
Abstract Gasoline Direct Injection (GDI) engines have attracted interest as automotive power-plants because of their potential advantages in down-sizing, fuel efficiency and in emissions reduction. However, GDI engines suffer from elevated unburned hydrocarbon (HC) emissions during start up process, which are sometimes worsened by misfires and partial burns. Moreover, as the engine is cranked to idle speed quickly in HEVs (Hybrid Electric Vehicle), the transients of quick starts are more dramatically than that in traditional vehicle, which challenge the optimization of combustion and emissions. In this study, test bench had been set up to investigate the GDI engine performances for ISG (Integrated Starter and Generator) HEVs during start up process. Based on the test system, cycle-controlled of the fuel injection mass, fuel injection timing and ignition timing can be obtained, as well as the cycle-resolved measurement of the HC concentrations and NO emissions. This paper focus on the detailed effects of coolant temperature, fuel temperature, cranking speed, injection timing and total equivalence ratio on the combustion and emission characteristics of the GDI engine under stratified combustion condition during the engine quick start process cycle by cycle.
2014-10-13
Technical Paper
2014-01-2794
Vicente Macian, Bernardo Tormos, Santiago Ruiz, Leonardo Ramirez Roa, Javier de Diego
Abstract This paper shows the results of a fuel consumption in-use comparison test where the effect of Low Viscosity Oils (LVO) was evaluated over a sample of 39 urban buses powered by Diesel and CNG engines. The aim of the test was to verify the fuel consumption benefits of LVO in Heavy Duty Vehicles (HDV) found in previous works, which were obtained mainly in engine test bench, when engines are working on “on-Road” conditions. In order to achieve this goal, a sample of 39 urban buses was studied over an Oil Drain Interval or 30.000 km (approximately an 11 month period), measuring daily mileage and fuel consumed to calculate each bus fuel consumption. Mileage was measured by GPS and fuel consumed was measured from refueling system. The sample was divided into two groups; a control group of buses using reference oils (SAE grade viscosities of 15W-40 and 10W-40) and a candidate group using LVO oils (SAE grade viscosities 5W-30). As kinematic viscosity at 100°C and High Temperature High Shear (HTHS) viscosity at 150°C have shown a good correlation with engine fuel consumption, an oil sampling program was implemented to study the possible variation of these oil parameters and its effect on the fleet fuel consumption during the test.
2014-10-13
Technical Paper
2014-01-2802
Qian Feng, Diming Lou, Piqiang Tan, Zhiyuan Hu
Abstract Durability and performance evaluation of the ageing catalyzed continuously regenerating trap (CCRT) on solid and volatile particles from diesel bus were studied through a set of transient TSI engine exhaust particle sizer spectrometer based on on-road test. Particle characteristics under stepped steady conditions and during regeneration were discussed in detail. Under idle and stepped steady conditions, total particle number and mass Emission Rate (ER) of each test presented rising trends as speed increase. Total number ERs of all tests showed downtrend as the CCRT aging. The particle number size distributions at different ageing stage showed changing characteristics due to developing filter mechanism. Compared with baseline data, the total number reduction rates at idle condition were incremental, from 91.4% to 98.9% as the CCRT ageing. Percentages of nuclei mode concentrations took higher range from 66.6% to 89.9% compared with the baseline data, 43.2-43.7%. Obvious uncontrolled regenerations were monitored at sudden shift from high-speed to idle, which were dangerous to passengers who were waiting for the bus and should be taken special attention.
2014-10-13
Technical Paper
2014-01-2784
Ben Leach, Richard Pearson
Abstract Rising fuel prices and changes to CO2 and fuel economy legislation have prompted an interest in the electrification of vehicles since this can significantly improve vehicle tailpipe CO2 emissions over homologation test cycles. To this end plug-in hybrid electric vehicles (PHEVs) and range extended electric vehicles (REEVs) have been introduced to the market. The operation of the engines in these vehicles differs from conventional vehicles in several key ways. This study was conducted to better understand how the engine design and control strategy of these vehicles affects the temperature and operating regimes experienced by engine crankcase lubricants. A Toyota Prius Plug-in PHEV and GM Volt REEV were tested on a chassis dynamometer over several legislated and pseudo ‘real world’ drive cycles to determine the operating strategy and behaviour of the powertrain. The lubricant and coolant temperatures were monitored, together with other key control parameters. Tests were completed with both hot and cold engine starts at 25°C and −7°C test cell temperatures in charge-depleting and charge-sustaining operating modes.
Viewing 1 to 30 of 17835