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2017-09-19
Technical Paper
2017-01-2047
Tyler Vincent, Joseph Schetz, K. Lowe
Analysis and design of total temperature probes for accurate measurements in hot, high-speed flows remains a topic of great interest in aerospace propulsion and a number of other engineering areas. Despite an extensive prior literature on the subject, prediction of error sources from convection, conduction and radiation is still an area of great concern. For hot-flow conditions, the probe is normally mounted in a cooled support, leading to substantial axial conduction along the length of the probe. Also, radiation plays a very important role in most hot, high-speed conditions. One can apply detailed computational methods for simultaneous convection, conduction and radiation heat transfer, but such approaches are not suitable for rapid, routine analysis and design studies. So, there is still a place for approximate methods, and that is the subject of this paper.
2017-09-19
Technical Paper
2017-01-2056
Daniel Aceituna
Abstract The goal behind Functional Safety is to anticipate the potential hazard scenarios (a.k.a. harm sequences) that a system may produce and address those scenarios in such a way as to mitigate or even eliminate them. A major challenge in determining hazard scenarios is trying to assess an adequate amount of scenarios, considering the large size of a hazard space. Typically assessing the entire hazard space is difficult to achieve, resulting in the possibility of overlooking some critical scenarios that can result in harm to either system operators, system by-standers, or both. In this paper we will explore a rule-based approach for concisely describing hazard scenarios, which could potentially enable us to examine the entire hazard space in a short amount of time. Our approach, called Hazard Space Analysis, combines three key activates: determining hazard scenarios, assigning a risk factor to those scenarios, and mapping those hazard scenarios directly to safety rules.
2017-03-28
Technical Paper
2017-01-1728
Nitin Singh, Aayoush Sharma, Sameer Shah, Balakumar Gardampaali
Abstract In any unlikely event of accidents or vehicle breakdown, there is accumulation of traffic which results in road-blockage and causes in convenience to other vehicles. If this happens in remote areas, the accidents victims are left unattended and there is delay in providing emergency services. In case of traffic, it obstructs the entry of ambulance and rescue team which results in death of passengers. To prevent this mishap, a mechatronics based road block avoidance and accident alarming system is designed which is automated by the use of sensors. The road-block is detected with the help sensors located at regular intervals on road. This input is given to a Local Control Unit (LCU) which is integrated on every road. Several such LCUs are connected to a Main Control Unit (MCU) which is located at the nearest police station. A single MCU covers the area administered by that police station. Additional CCTV cameras are present to give graphical view of accident.
2017-03-28
Technical Paper
2017-01-0061
Sultan A.M Alkhteeb, Shigeru Oho, Yuki Nagashima, Seisuke Nishimura, Hiroyuki Shimizu
Abstract Lightning strikes on automobiles are usually rare, though they can be fatal to occupants and hazardous to electronic control systems. Vehicles’ metal bodies are normally considered to be an effective shield against lightning. Modern body designs, however, often have wide window openings, and plastic body parts have become popular. Lightning can enter the cabin of vehicles through their radio antennas. In the near future, automobiles may be integrated into the electric power grid, which will cause issues related to the smart grid and the vehicle-to-grid concept. Even today, electric vehicles (EVs) and plug-in hybrid vehicles (PHEVs) are charged at home or in parking lots. Such automobiles are no longer isolated from the power grid and thus are subject to electric surges caused by lightning strikes on the power grid.
2017-03-28
Technical Paper
2017-01-1353
Michael G. Leffert
Abstract This paper compares the material consumption and fire patterns which developed on four nearly identical compact sedans when each was burned for exactly the same amount of time, but with different wind speed and direction during the burns. This paper will also compare the effects of environmental exposure to the fire patterns on the vehicles. The burn demonstrations were completed at an outdoor facility in southeast Michigan on four late model compact sedans. The wind direction was controlled by placing the subject vehicle with either the front facing into the wind, or rear facing into the wind. Two of the burns were conducted when the average observed wind speed was 5-6kph and two of the burns were conducted at an average observed wind speed of 19kph.
2017-03-28
Technical Paper
2017-01-1355
Paul H. DeMarois, Bill Pappas, William G. Ballard, Jeffrey R. Williams, Gregory West
Abstract Four full scale burn tests on aluminum body Ford F-150’s were conducted with four unique origins. The purpose of these burn tests was to determine if the origin of the fire could be accurately identified after the vehicle fires progressed to near complete burn (with near absence of the aluminum body panels). The points of origin for the four burn tests were: 1) Engine Compartment - driver’s side front of engine compartment, 2) Passenger Compartment - Instrument panel, driver’s side near the headlamp switch, 3) Passenger Compartment - passenger side rear seat, 4) Outside of Vehicle - passenger side front tire. Photographic, video, and temperature data was recorded to document the burn process from initiation to extinguishment. Post-fire analysis was conducted in an attempt to determine the origin of the fire based solely on the burn damage.
2017-03-28
Technical Paper
2017-01-1354
Timothy Morse, Michael Cundy, Harri Kytomaa
Abstract One potential fire ignition source in a motor vehicle is the hot surfaces on the engine exhaust system. These hot surfaces can come into contact with combustible and flammable liquids (such as engine oil, transmission fluid, brake fluid, gasoline, or Diesel fuel) due to a fluid leak, or during a vehicle collision. If the surface temperature is higher than the hot surface ignition temperature of the combustible or flammable liquid in a given geometry, a fire can potentially ignite and propagate. In addition to automotive fluids, another potential fuel in post-collision vehicle fires is grass, leaves, or other vegetation. Studies of hot surface ignition of dried vegetation have found that ignition depends on the type of vegetation, surface temperature, duration of contact, and ambient conditions such as temperature and wind speed. Ignition can occur at surface temperatures as low as 300 °C, if the vegetation is in contact with the surface for 10 minutes or longer.
2017-03-28
Journal Article
2017-01-1351
Vamshi Korivi, Steven McCormick, Steven Hodges
Abstract The US Army Tank Automotive Research, Development and Engineering Center (TARDEC) has developed a unique physics based modeling & simulation (M&S) capability using Computational Fluid Dynamics (CFD) techniques to optimize automatic fire extinguishing system (AFES) designs and complement vehicle testing for both occupied and unoccupied spaces of military ground vehicles. The modeling techniques developed are based on reduced global kinetics for computational efficiency and are applicable to fire suppressants that are being used in Army vehicles namely, bromotrifluoromethane (Halon 1301), heptafluoropropane (HFC-227ea, trade name FM200), sodium-bicarbonate (SBC) powder, water + potassium acetate mixture, and pentafluoroethane (HFC-125, trade name, FE-25). These CFD simulations are performed using High Performance Computers (HPC) that enable the Army to assess AFES designs in a virtual world at far less cost than physical-fire tests.
2017-03-28
Journal Article
2017-01-1352
David Gardiner
Abstract This paper presents an experimental study of the vapour space flammability of Fuel Ethanol (a high-ethanol fuel for Flexible Fuel Vehicles, commonly known as “E85”) and gasoline containing up to 10% ethanol (commonly known as “E10”). The seasonal minimum vapour pressure limits in specifications for automotive spark ignition fuels are intended, in part, to minimize the formation of flammable mixtures in the headspace of vehicle fuel tanks. This is particularly important at subzero temperatures, where the headspace mixture may not be rich enough to prevent combustion in the presence of an ignition source such as a faulty electrical fuel pump. In the current study, the upper temperature limits of flammability were measured for field samples of “E85” and “E10”, and a series of laboratory-prepared blends of denatured ethanol, Before Oxygenate Blending (BOB) gasoline, and n-butane.
2017-03-28
Journal Article
2017-01-0716
Randy Hessel, Zongyu Yue, Rolf Reitz, Mark Musculus, Jacqueline O'Connor
Abstract One way to develop an understanding of soot formation and oxidation processes that occur during direct injection and combustion in an internal combustion engine is to image the natural luminosity from soot over time. Imaging is possible when there is optical access to the combustion chamber. After the images are acquired, the next challenge is to properly interpret the luminous distributions that have been captured on the images. A major focus of this paper is to provide guidance on interpretation of experimental images of soot luminosity by explaining how radiation from soot is predicted to change as it is transmitted through the combustion chamber and to the imaging. The interpretations are only limited by the scope of the models that have been developed for this purpose. The end-goal of imaging radiation from soot is to estimate the amount of soot that is present.
2016-11-08
Journal Article
2016-32-0058
Makoto Hasegawa, Takanobu Kaneko
Abstract ISO 26262, an international functional safety standard of electrical and/or electronic systems (E/E systems) for motor vehicles, was published in November 2011 and it is expected that the scope will be extended to motorcycles in a second edition of ISO 26262 going to be published in 2018. In order to apply ISO 26262 to motorcycle, proper estimation of Exposure, Controllability, and Severity are key factors to determine Motorcycle Safety Integrity Level (MSIL). Exposure is a factor to indicate the probability of the state of an operational situation that can be hazardous with the E/E system malfunction. And it is not easy to estimate the motorcycle Exposure due to less availability of back ground data in actual operational situation compared to motor vehicle. Therefore real traffic situation should be investigated in order to provide rationales for MSIL determination.
2016-09-27
Technical Paper
2016-01-8114
Massimiliano Ruggeri, Pietro Marani, Michele Selvatici
Abstract Stationary (parking) brake is a very important and safety critical function in many classes of machines. The new transmissions and the “by wire” systems increase the criticality of the role of stationary brake, as it is also an emergency (secondary) brake, and it’s often used to hold the vehicle when the transmission is not locking the wheels. As an example, dual clutch and power-shift transmission gear systems, as well as hydrostatic transmissions under certain circumstances, are often unable to hold the vehicle stopped and this function is provided by the stationary brake. Due to the main need of having the brake actuated when vehicle is stopped, without any hydraulic and electric power, the brake configuration is normally a “negative” configuration, usually called “spring applied” because of the actuator configuration, but this configuration causes the brake actuation when de-energized, even in case of system failure.
2016-09-20
Technical Paper
2016-01-1999
Debabrata Pal, Frank Feng
Abstract In 3-phase AC application, there is additional heat dissipation due to skin effects and proximity effects in bus bars. In addition, when the 3- phase AC is used to drive a motor at high fundamental frequency, for example between 666 Hz and 1450 Hz, there are higher bus bar losses due to presence of higher frequency harmonic content. High frequency current carrying bus bars in aircraft power panels are typically cooled by natural convection and radiation. In this paper a thermal and electrical finite element analysis (FEA) is done for a bus bar system. For electrical loss modeling, 3D electromagnetic FEA is used to characterize losses in three parallel bus bars carrying AC at various frequencies. This loss analysis provides correlation of heat loss as function of frequency. A method is presented where this AC loss is incorporated using computational fluid dynamics (CFD) based thermal model.
2016-04-05
Technical Paper
2016-01-0538
Cynthia Templeman
Abstract Automotive clearcoats have many purposes, from providing a glossy finish to protecting the underlying paint layers from UV radiation. Yellowing of clearcoats is a natural phenomenon during weathering processes, as well as from extreme baking conditions, due to polymer degradation. However, occasionally yellowing may be caused by unexpected chemical reactions occurring in the clearcoat. These reactions may happen very quickly (within hours or days) or take years to manifest, as other chemicals migrate into the clearcoat. We have investigated one family of these unexpected reactions which occur with certain UV absorbers, as well as how to prevent the reactions from occurring. We found that certain benzotriazole UV absorbers react readily with some common metals, including copper and zinc, provided that the UV absorber is not in its excited state.
2016-04-05
Technical Paper
2016-01-0725
P.C. Bakker, R.C. Willems, N.J. Dam
Abstract Laser-induced incandescence (LII) is a well-established technique for tracking soot, potentially enabling soot volume fraction determination. To obtain crank angle resolved data from a single cycle, a multi-kHz system should be applied. Such an approach, however, imposes certain challenges in terms of application and interpretation. The present work intends to apply such a high-speed system to an optically-accessible, compression ignition engine. Possible problems with sublimation, local gas heating or other multishot effects have been studied on an atmospheric co-flow burner prior to the engine experiments. It was found that, in this flame, fluences around 0.1 J/cm2 provide the best balance between signal-tobackground ratio, and soot sublimation. This fluence is well below the plateau regime of LII, which poses additional problems with interpretation of the signal.
2016-04-05
Technical Paper
2016-01-1424
Yi G. Glaser, Robert E. Llaneras, Daniel S. Glaser, Charles A. Green
Abstract Partially automated driving involves the relinquishment of longitudinal and/or latitudinal control to the vehicle. Partially automated systems, however, are fallible and require driver oversight to avoid all road hazards. Researchers have expressed concern that automation promotes extended eyes-off-road (EOR) behavior that may lead to a loss of situational awareness (SA), degrading a driver’s ability to detect hazards and make necessary overrides. A potential countermeasure to visual inattention is the orientation of the driver’s glances towards potential hazards via cuing. This method is based on the assumption that drivers are able to rapidly identify hazards once their attention is drawn to the area of interest regardless of preceding EOR duration. This work examined this assumption in a simulated automated driving context by projecting hazardous and nonhazardous road scenes to a participant while sitting in a stationary vehicle.
2016-04-05
Technical Paper
2016-01-1683
Blago B. Minovski, Lennart Lofdahl, Peter Gullberg
Abstract Presented are results from numerical investigations of buoyancy driven flow in a simplified representation of an engine bay. A main motivation for this study is the necessity for a valid correlation of results from numerical methods and procedures with physical measurements in order to evaluate the accuracy and feasibility of the available numerical tools for prediction of natural convection. This analysis is based on previously performed PIV and temperature measurements in a controlled physical setup, which reproduced thermal soak conditions in the engine compartment as they occur for a vehicle parked in a quiescent ambient after sustaining high thermal loads. Thermal soak is an important phenomenon in the engine bay primarily driven by natural convection and radiation after there had been a high power demand on the engine. With the cooling fan turned off and in quiescent environment, buoyancy driven convection and radiation are the dominating modes of heat transfer.
2016-04-05
Journal Article
2016-01-0280
Alaa El-Sharkawy, Amr Sami, Abd El-Rahman Hekal, Dipan Arora, Masuma Khandaker
Abstract In this paper, the development of a transient thermal analysis model for the exhaust system is presented. Given the exhaust gas temperature out of the engine, a software tool has been developed to predict changes in exhaust gas temperature and exhaust surface temperature under various operating conditions. The software is a thermal solver that will predict exhaust gas and wall surface temperatures by modeling all heat transfer paths in the exhaust system which includes multi-dimensional conduction, internal forced/natural convection, external forced/natural convection, and radiation. The analysis approach involves the breaking down of the thermal system into multiple components, which include the exhaust system (manifold, takedown pipe, tailpipe, etc.), catalytic converter, DPF (diesel particulate filter), if they exist, thermal shields, etc. All components are modeled as 1D porous and 1D non-porous flow streams with 3D wall layers (solid and air gaps).
2016-04-05
Journal Article
2016-01-0281
Alaa El-Sharkawy, Dipan Arora, Abd El-Rahman Hekal, Amr Sami, Muhannad Hendy
Abstract In this paper, transient component temperatures for the vehicle under-hood and underbody are estimated. The main focus is on the component temperatures as a result of radiation from exhaust, convection by underbody or under-hood air and heat conduction through the components. The exhaust surface temperature is simulated as function of time and for various vehicle duty cycles such as city traffic, road load and grade driving conditions. At each time step the radiation flux to the surrounding component is estimated, heat addition or removal by convection is evaluated based on air flow, air temperature and component surface area. Simulation results for under-hood and underbody components are compared against vehicle test data. The comparison shows very good agreement between simulated and measured component temperatures under both steady state and transient conditions.
2016-04-05
Technical Paper
2016-01-0206
Ken T. Lan
An Air intake system (AIS) is a duct system which leads the airflow going into the internal combustion engine. Combustion requires oxygen, and the more oxygen is provided into the combustion process the more power it will produce. The lower the air temperature, the higher its density, and hence there is more oxygen in a unit volume. The quality of air entering engine can be measured with the air temperature. AIS design and routing influence the air charge temperature (ACT) at intake manifold runners and ACT is normally measured at AIS throttle body in reality. Higher ACT lead to inefficient combustion and can lead to spark retard. Optimization of AIS designs and reduction of ACT can improve engine performance and vehicle fuel economy. High ACT can be a result of two different phenomena: Recirculation - Hot air from the underhood environment ingested into the dirty side of the air intake system.
2016-04-05
Technical Paper
2016-01-0246
Rupesh Sonu Kakade, Prashant Mer
Abstract Vehicle occupants, unlike building occupants, are exposed to continuously varying, non-uniform solar heat load. Automotive manufacturers use photovoltaic cells based solar sensor to measure intensity and direction of the direct-beam solar radiation. Use of the time of the day and the position - latitude and longitude - of a vehicle is also common to calculate direction of the direct-beam solar radiation. Two angles - azimuth and elevation - are used to completely define the direction of solar radiation with respect to the vehicle coordinate system. Although the use of solar sensor is common in today’s vehicles, the solar heat load on the occupants, because of their exposure to the direct-beam solar radiation remains the area of in-car subjective evaluation and tuning. Since the solar rays travel in parallel paths, application of the ray tracing method to determine solar insolation of the vehicle occupants is possible.
2016-04-05
Technical Paper
2016-01-0135
Ji Zhang, Mengjing Shen, Xiangyu Zhu, Qipeng Chen
Abstract Nowadays researches of automotive electromagnetic field mainly focus on the component level and electromagnetic compatibility, while there is a lack of relevant studies on internal electromagnetic environment of the vehicles. With the increasingly complex internal electromagnetic environment of the vehicle, people are increasingly concerned about its potential impact of human health. This article researches on a type of electric vehicle and the occupants and analyses its electromagnetic radiation effects on human health. Firstly, considering the characters of Pro/E, Hypermesh and FEKO, the “Characteristics grouping subdivision” method is used to establish the entire vehicle body FE model. According to the requirement of MOM/FEM method, the entire vehicle model is optimized to be a high quality body model with simple construction and moderate grid size.
2016-04-05
Journal Article
2016-01-0527
Anthony Berejka, Dan Montoney, Dan Dispenza, Len Poveromo, Rick Galloway, Marshall Cleland, Mark Driscoll
Abstract The power demands in terms of kilowatt-hour electrical use were compared for autoclave curing commercial thermosetting carbon fiber pre-pregs with an innovative alternative of high energy X-ray curing. An automotive component, now made with carbon fiber composites, was selected as an illustrative example, an Aston-Martin hood. Temperature resistant polyester molds for these hoods were used and manufacturer recommended autoclave curing conditions were followed. X-rays, which can penetrate about 15 cm (6 inches) in unit density materials (or less into higher density materials as molds), were used to cure pre-pregs made with a specialty matrix material using the same molds, but doing so without adding any heat for curing. High energy X-ray equipment, generated from a 7 MeV, 700 kW electron beam, is in commercial use for medical device sterilization. This same equipment can also be used for composite curing.
2016-04-05
Journal Article
2016-01-0340
Tina Hull, Monika A. Minarcin
Abstract Applications using industrial robotics have typically led to establishing a safeguarded space encompassing a wide radius around the robot. Operator access to this hazard zone was restricted by a combination of means, such as hard guarding, safeguarding, awareness means, and personal protective equipment. The introduction of collaborative robots is redefining safeguarding requirements. Many collaborative robots have inherently safe designs that enable an operator and a robot to work within a shared, collaborative workspace. New technology in industrial robotics has opened up opportunities for collaborative operation. Collaborative operation could include either industrial or collaborative robots, depending on its application. The current defined modes of collaborative operation are hand guiding; speed and separation monitoring; safety-rated monitored stop; and, power and force limiting.
2016-04-05
Technical Paper
2016-01-0333
Pavel Lykov, Rustam Baytimerov, Sergey Vaulin, Evgeny Safonov, Dmitry Zherebtsov
Abstract Due to its unique physical properties (high thermal and electric conductivity) copper is one of the most interesting materials in point of view of additive manufacturing in particular of Selective Laser Melting (SLM). But because of the low laser radiation absorption, low melting point and high thermal conductivity it is difficult to fabricate of copper components without pores. Results of many research have been shown that for successful Selective Laser Melting of copper powder is needed high laser power (more than 300 W) and high laser scanning speed (more than 600 mm/s). However now most SLM machines are equipped with laser plants with output power up to 200 W.In this research, SLM machine with 200 W maximum power CO2 laser has been used. For determination of the influence of SLM process parameters on quality of copper parts cubic specimens have been fabricated. The point distance, exposure time and base plate preheating temperature have been changing.
2016-04-05
Journal Article
2016-01-1080
Narendra V. Bansode, Arnab Ganguly, Vikas Kumar Agarwal
Abstract A single cylinder gasoline engine of a sports bike generates sufficient hot gases to pose great challenge to the designers of exhaust system. The high temperature exhaust gases in muffler creates thermal elongation on the solid parts of exhaust system, which is mounted on the chassis. This arrangement induces thermal stress in exhaust assembly. It is necessary to analyze this thermal stress to ensure the durability of muffler components. The exhaust design has a diversion at the header pipe to distribute the flow in two branches. This junction and the branches heated up excessively and showed repeated failure. To analyze the thermal stress, the temperature distribution in the muffler components is obtained from Computational Fluid Dynamics (CFD) analysis. The complete motorcycle with detailed exhaust system is modelled in the standard wind tunnel using a commercial CFD software.
2016-04-05
Technical Paper
2016-01-1158
Toshiaki Watanabe, Masaya Ishida
Abstract Wireless charging systems for electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) employing the resonant magnetic coupling method and using induction coils have been intensively studied in recent years. Since this method requires kW class high power to be transmitted using resonant magnetic coupling in the high frequency range, it is necessary to pay attention to the leakage of the magnetic field generated by the coil current, and to its influence on surrounding objects, particularly human bodies. Noting that acceptable values for human body exposure to electromagnetic fields have previously been issued by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) as guidelines, we have developed a method for predicting product compliance with those guidelines at the basic design development stage.
2016-04-05
Technical Paper
2016-01-1266
Shinichi Urabe, Kazutaka Kimura, Yuki Kudo, Akinori Sato
Abstract Solar and other green energy technologies are attracting attention as a means of helping to address global warming caused by CO2 and other emission gases. Countries, factories, and individual homes around the world have already introduced photovoltaic energy power sources, a trend that is likely to increase in the future. Electric vehicles powered from photovoltaic energy systems can help decrease the CO2 emmissions caused by vehicles. Unlike vehicles used for solar car racing, it is not easy to equip conventional vehicles with solar modules because the available area for module installation is very small to maintain cabin space, and the body lines of conventional vehicles are also usually slightly rounded. These factors decrease the performance of photovoltaic energy systems and prevent sufficient electric power generation. This research aimed to estimate the effectiveness of a solar module power generating system equipped on a conventional car, the Toyota Prius PHV.
2016-04-05
Technical Paper
2016-01-1286
Takuya Hara, Takahiro Shiga, Kazutaka Kimura, Akinori Sato
Abstract Introducing effective technologies to reduce carbon emissions in the transport sector is a critical issue for automotive manufacturers to contribute to sustainable development. Unlike the plug-in electric vehicles (PEVs), whose effectiveness is dependent on the carbon intensity of grid electricity, the solar hybrid vehicle (SHV) can be an alternative electric vehicle because of its off-grid, zero-emission electric technology. Its usability is also advantageous because it does not require manual charging by the users. This study aims at evaluating the economic, environmental, and usability benefits of SHV by comparing it with other types of vehicles including PEVs. By setting cost and energy efficiency on the basis of the assumed technology level in 2030, annual cost and annual CO2 emissions of each vehicle are calculated using the daily mileage pattern obtained from a user survey of 5,000 people in Japan and the daily radiation data for each corresponding user.
2016-04-05
Journal Article
2016-01-1409
J. Christopher Watson, Gennady Dumnov, Alexander Muslaev, Andrey Ivanov, Svetlana Shtilkind
Abstract Condensation occurrence in automotive headlights can be detrimental to consumer acceptance of a product. This paper describes a technique for transient numerical simulation of liquid film formation on surfaces during lighting thermal analysis performed using Computational Fluid Dynamics (CFD), including how the film’s properties influence the thermal solution. The numerical technique presented accounts for the change in the film thermal state and thickness due to heat exchange with external fluid flow and solid bodies, surface evaporation/condensation, melting/crystallization within the film volume, and its motion due to gravity and friction forces from the surrounding airflow. Additionally, accurate modeling of radiation effects is critical for lighting applications, including the attendant influence on the thermal distribution of the solids that may have surfaces subject to condensation.
Viewing 1 to 30 of 820