Criteria

Display:

Results

Viewing 271 to 300 of 8633
2016-04-05
Technical Paper
2016-01-1417
Toshinao Fukui, Kazuhiko Nakamoto, Hiroyuki Satake
Abstract The use of a head-up display (HUD) system has become popular recently, as it can provide feedback information at a position easily seen by the driver. However, the outline of the HUD bezel often reflects on the windshield of a HUD equipped vehicle. This phenomenon occurs when the sun is at a high position and reflects off the top of the instrument panel and the front view is dark. For this reason, it can occur when driving on asphalt paved roads, causing annoyance to the driver. Under fixed environmental conditions, the vehicle based factors that influence the annoyance caused by reflected boundary lines are the position of the reflection, line thickness, and the contrast of the reflected boundary line. These can be represented by the conspicuity of a striped pattern (contrast sensitivity function). In previous research in 1991, M. S. Banks et al. studied a contrast sensitivity function that included the factors stated above.
2016-04-05
Technical Paper
2016-01-1429
Jangwoon Park, Sheila Ebert-Hamilton, K. Han Kim, Monica Jones, Byoung-Keon Park, Matthew Reed
Abstract This paper reports on the development and validation of an automated seat-dimension extraction system that can efficiently and reliably measure SAE J2732 (2008) seat dimensions from 3D seat scan data. The automated dimension-extraction process consists of four phases: (1) import 3D seat scan data along with seat reference information such as H-point location, back and cushion angles, (2) calculate centerline and lateral cross-section lines on the imported 3D seat scan data, (3) identify landmarks on the centerline and cross-section lines based on the SAE J2732 definitions, and (4) measure seat-dimensions using the identified landmarks. To validate the automated seat measurements, manually measured dimensions in a computer-aided-design (CAD) environment and automatically extracted ones in the current system were compared in terms of mean discrepancy and intra- and inter-observer standard deviations (SD).
2016-04-05
Technical Paper
2016-01-1430
Se Jin Park, Murali Subramaniyam, Seoung Eun Kim, Tae Hyun Kim, Hee Su Sin, Dong Hag Seo, Hyu Hyeong Nam, Jeong Cheol Lee
Abstract Seating comfort is associated with the various factors, and one of the principal components of a vehicle environment which can affect passenger’s comfort is vibration. The seat design plays a vital role in the vibration isolation. In recent years, automotive seat designers are paying more attention for the improvement of seat cushion properties. This paper provides information about a new automotive seat concept that use double-wall 3D air-mat in cushion along with foam cushion in the seat cushion system. To test the developed seat on vibration isolation characteristics, seating comfort, and ride quality experiments have been performed. This research is divided into two parts. At first, the newly developed seat tested on the motion simulator. In study 2, road tests were performed on the national highway. Two tri-axial accelerometers were used to measure acceleration at the foot and hip in two different seats (seat with and without double-wall 3D air-mat).
2016-04-05
Technical Paper
2016-01-1436
K. Han Kim, Sheila Ebert-Hamilton, Matthew Reed
Abstract Automotive seats are commonly described by one-dimensional measurements, including those documented in SAE J2732. However, 1-D measurements provide minimal information on seat shape. The goal of this work was to develop a statistical framework to analyze and model the surface shapes of seats by using techniques similar to those that have been used for modeling human body shapes. The 3-D contour of twelve driver seats of a pickup truck and sedans were scanned and aligned, and 408 landmarks were identified using a semi-automatic process. A template mesh of 18,306 vertices was morphed to match the scan at the landmark positions, and the remaining nodes were automatically adjusted to match the scanned surface. A principal component (PC) analysis was performed on the resulting homologous meshes. Each seat was uniquely represented by a set of PC scores; 10 PC scores explained 95% of the total variance. This new shape description has many applications.
2016-04-05
Technical Paper
2016-01-1435
Amber Hall, Michael Kolich
Abstract Many studies have been conducted and supporting literature has been published to better understand thermal comfort for the automotive environment, particularly, for the HVAC system within the cabin. However, reliable assessment of occupant thermal comfort for seating systems has lacked in development and understanding. Evaluation of seat system performance in terms of comfort has been difficult to quantify and thus most tests have been established such that the hardware components are tested to determine if the thermal feature does no harm to the customer. This paper evaluates the optimal seat surface temperature range to optimize human thermal comfort for an automotive seating system application for heated and ventilated seats.
2016-04-05
Technical Paper
2016-01-1438
Alexander Siefert
Abstract The objective evaluation of occupant comfort is a complex task where numerous aspects such as posture, pressure distribution, internal tissue loads, handling of steering wheel or gear shift have to be taken into consideration. Currently the standard evaluation procedures are hardware tests with human subjects, who are sensitive to all these aspects. However, the reproducibility of subjective tests for the comparison of design variants is a questionable issue and the costs for each test cycle with new prototypes are very high. As an alternative, numerical approaches using human body models such as AnyBody [1], CASIMIR [2] or RAMSIS [3] are applied. Here the issue of reproducibility does not exist and only little effort is required to investigate new setups. However, the disadvantage is that each approach focuses only on one specific aspect of occupant comfort, while in reality the emotions of the occupant are always a combination of all impressions.
2016-04-05
Technical Paper
2016-01-1432
Alexander Siefert
Abstract Predicting the vibration comfort is a difficult challenge in seat design. There is a broad range of requirements as the load cases strongly vary, representing different excitation levels, e.g. cobblestones or California roads. Another demand is the driver expectation, which is different for a pickup and a sports car. There are several approaches for assessing the vibrations of occupants while driving. One approach is the evaluation of comfort by integral quantities like the SEAT value, taking into account a weighting based on the human body sensitivity. Another approach is the dimension of perception developed by BMW, which is similar to psychoacoustics as the frequency range is separated with respect to occurring vibration phenomena. The seat transmissibility is in the focus of all activities. In the frequency range it defines the relation between the input at the seat slides and the output at the interface of human body and trim.
2016-04-05
Technical Paper
2016-01-1437
Giorgio Previati, Massimiliano Gobbi, Giampiero Mastinu
Abstract The paper is focused on both the subjective and the objective ride comfort evaluation of farm tractors. The experimental measurement of the relevant accelerations occurring at the tractor body, at the cabin and at the seat was performed on a number of different farm tractors. A subjective rating of the ride comfort level was performed by considering five different drivers. The comfort index was computed according with ISO 2631 and other standards. The acceleration of the seated subject was computed by means of a proper mechanical model of a farm tractor and derived at different positions on the subject body. It turned out that the acceleration of the lower torso was particularly relevant for establishing a matching between the subjective perception and the objective measurement and computation. A number of indices have been derived from the measured data which are able to correlate the subjective driver feeling with the measured accelerations.
2016-04-05
Technical Paper
2016-01-1431
Subramanian Premananth, Ganesh Dharmar, Hareesh Krishnan, Riyaz Mohammed
Abstract Virtual assessment of an occupant postural ergonomics has become an essential part of vehicle development process. To design vehicle for different market is one of the primary reason for manufacturers using digital tools to address the specific needs of the target market including cultural background, road and traffic conditions. RAMSIS is a widely used software for creating digital human models (DHM) of different target population which allows manufacturers to assess design with unique customer requirements in product design. Defining these requirements with RAMSIS human module helped development team to accurately define occupant targets such as occupant space, visibility and reachability etc. Occupant behavior and usage scenario are factors which are unique to target market and they influence the occupant posture and usage pattern inside the vehicle.
2016-04-05
Technical Paper
2016-01-1433
Gregory Schaupp, Julia Seeanner, Casey Jenkins, Joseph Manganelli, Sarah Hennessy, Constance Truesdail, Lindsay Swift, Paul Venhovens, Johnell Brooks
Abstract The ability to independently transfer into and out of a vehicle is essential for many wheelchair users to achieve driving independence. This paper presents the results of an exploratory study that investigated the transfer strategies of wheelchair users who drive from their driver’s seat and not from their wheelchair. The goal of this study was to identify typical ingress and egress motions as well as “touch points” of wheelchair users transferring into and out of the driver’s seat. While motion databases exist for the ingress and egress of able-bodied drivers, this study provides insight on drivers with physical disabilities. Twenty-five YouTube videos of wheelchair users who transferred into and out of their own sedans were analyzed.
2016-04-05
Technical Paper
2016-01-1444
Shayne McConomy, Johnell Brooks, Paul Venhovens, Yubin Xi, Patrick Rosopa, John DesJardins, Kevin Kopera, Kathy Lococo
Abstract The research objective was to measure and understand the preferred seat position of older drivers and younger drivers within their personal vehicles to influence recommended practices and meet the increased safety needs of all drivers. Improper selection of driver’s seat position may impact safety during a crash event and affect one’s capacity to see the roadway and reach the vehicle’s controls, such as steering wheel, accelerator, brake, clutch, and gear selector lever. Because of the stature changes associated with ageing and the fact that stature is normally distributed for both males and females, it was hypothesized that the SAE J4004 linear regression would be improved with the inclusion of gender and age terms that would provide a more accurate model to predict the seat track position of older drivers. Participants included 97 older drivers over the age of 60 and 20 younger drivers between the ages of 30 to 39.
2016-04-05
Technical Paper
2016-01-1443
Nazan Aksan, Lauren Sager, Sarah Hacker, Benjamin Lester, Jeffrey Dawson, Matthew Rizzo
Abstract We examined relative effectiveness of heads-up visual displays for lane departure warning (LDW) 39 younger to middle aged drivers (25-50, mean = 35 years) and 37 older drivers (66-87, mean = 77 years). The LDW included yellow “advisory” visuals in the center screen when the driver started drifting toward the adjacent lane. The visuals turned into red “imminent” when the tires overlapped with the lane markers. The LDW was turned off if the driver activated the turn signal. The visuals could be easily segregated from the background scene, making them salient but not disruptive to the driver’s forward field of view. The visuals were placed adjacent to the left and right lane markers in the lower half of the center screen.
2016-04-05
Technical Paper
2016-01-1504
Monica Lynn Haumann Jones, Sheila Ebert-Hamilton, Matthew Reed
Abstract Law enforcement officers (LEO) make extensive use of vehicles to perform their jobs, often spending large portions of a shift behind the wheel. Few LEO vehicles are purpose-built; the vast majority are modified civilian vehicles. Data from the field indicate that LEO suffer from relatively high levels musculoskeletal injury that may be due in part to poor accommodation provided by their vehicles. LEO are also exposed to elevated crash injury risk, which may be exacerbated by a compromise in the performance of the occupant restraint systems due to body-borne equipment. A pilot study was conducted to demonstrate the application of three-dimensional anthropometric scanning and measurement technology to address critical concerns related to vehicle design. Detailed posture and belt fit data were gathered from five law enforcement officers as they sat in the patrol vehicles that they regularly used and in a mockup of a mid-sized vehicle.
2016-04-05
Technical Paper
2016-01-0100
Sushant Kishor Hingane
High-end vehicles with latest technology and autonomous driving experience have to bear the cost of increasing number of sensors on-board. It would be beneficial to reduce some of the sensors in the vehicle and make use of other available resources, retaining the same functionality. This paper discusses a novel technique of estimating the weight of seat occupant from an already existing DC motor without using additional pressure sensors. Passenger weight information is important for seat-belt reminder system as well as supplemental restraint system that will decide the air-bag deployment. The mathematical model for a series-type DC motor is analyzed and simulated using MATLAB. Further, results of the experiment performed on a lower capacity motor are shared and compared with the simulation results. Formulating a linear relation gives a possibility to develop a device for occupant weight measurement inside the high-end vehicles.
2016-04-05
Journal Article
2016-01-0282
Julio Carrera
Abstract Recent emissions standards have become more restrictive in terms of CO2 and NOx reduction. This has been translated into higher EGR rates at higher exhaust gas temperatures with lower coolant flow rates for much longer lifetimes. In consequence, thermal load for EGR coolers has been increasing and the interaction of boiling with thermal fatigue is now a critical issue during development. It is almost impossible to avoid localized boiling inside an EGR cooler and, in fact, it would not be strictly necessary when it is below the Critical Heat Flux (CHF). However when CHF is exceeded, film boiling occurs leading to the sudden drop of the heat transfer rate and metal temperature rise. In consequence, thermal stress increases even when film boiling is reached only in a small area inside the part. It is very difficult to accurately predict under which conditions CHF is reached and to establish the margins to avoid it.
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
Journal Article
2016-01-0186
Hyunki Sul, Taehoon Han, Mitchell Bieniek, John Hoard, Chih-Kuang Kuan, Daniel Styles
Abstract Exhaust gas recirculation (EGR) coolers are used on diesel engines to reduce peak in-cylinder flame temperatures, leading to less NOx formation during the combustion process. There is an ongoing concern with soot and hydrocarbon fouling inside the cold surface of the cooler. The fouling layer reduces the heat transfer efficiency and causes pressure drop to increase across the cooler. A number of experimental studies have demonstrated that the fouling layer tends to asymptotically approach a critical height, after which the layer growth ceases. One potential explanation for this behavior is the removal mechanism derived by the shear force applied on the soot and hydrocarbon deposit surface. As the deposit layer thickens, shear force applied on the fouling surface increases due to the flow velocity growth. When a critical shear force is applied, deposit particles start to get removed.
2016-04-05
Journal Article
2016-01-0186.01
Hyunki Sul, Taehoon Han, Mitchell S. Bieniek, John Hoard, Chih-Kuang Kuan, Daniel J. Styles
ERRATUM: In the article Reference 24 should read as follows: 24. Han, T., Booth, A., Song, S., Styles, D., and Hoard, J., “Review and A Conceptual Model of Exhaust Gas Recirculation (EGR) Cooler Fouling Deposition and Removal Mechanism” Proceedings of the Int. Conf. on Heat Exchanger Fouling and Cleaning, 2015”
2016-04-05
Technical Paper
2016-01-0185
Yangjie Ji, Jiaqi Wang, Yingxiao Xu, Ziang Liu, Yongchi Zhou, Jiawei Li
Abstract As an auxiliary braking device of heavy-duty vehicle, eddy current retarder can reduce the brake failure due to the high temperature of the main brake. Nevertheless, the eddy current retarder will generate high temperature locally during the working process of it, leading to the decline of the brake power. The study on the heating characteristics of eddy current retarder is advantageous to the layout and parameter design of the liquid cooling channel of the retarder body and prolong the effective time of the auxiliary brake. In this research, a new kind of integrated eddy current retarder has been established. The thermal-magnetic coupling characteristics are studied and the laws of variation in torque output of auxiliary brake affected by the body temperature of retarder are analyzed. The boundary conditions are provided for the construction of the cooling channel. Firstly, the distribution of magnetic field and the characteristics of eddy current are simulated.
2016-04-05
Journal Article
2016-01-0191
Gursaran D. Mathur
Water drainage characteristics of an evaporator changes with the age of the vehicle. This is due to the fact that with time, a part of the hydrophilic coating washes off with the moisture that condenses over the evaporator core from the air-stream. Hence, the effectiveness of the evaporator for water drainage deteriorates with the age of the vehicle. At this condition more water is retained in the evaporator as the contact angle increases. Author has conducted experiments with evaporators from multiple vehicles from different OEMs. These evaporators were analyzed to determine the effectiveness of the hydrophilic coating as a function of time or vehicle age. This is the first paper in the open literature that deals with the vehicle mileage or vehicle age with the evaporator plate contact angle and surface coating of an evaporator.
2016-04-05
Journal Article
2016-01-0189
Alaa El-Sharkawy, Ahmed Uddin
Abstract A heat pipe is a self-operating device which is capable of transferring large amounts of heat with a minimum temperature differences between the hot end (evaporator) and the cold end (condenser). However, a limited number of research work or analysis [1,2,3,4,5,6,7,8,9] has been reported in automotive industry on the applications of heat pipes in power train cooling. The advantage of a heat pipe heat exchanger is the possibility to use a more compact and lighter radiator. In addition, the proposed radiator is expected to be more robust as it is less sensitive to variations in ambient temperatures. In this paper, a proposed design for an automotive heat exchanger is investigated. The proposed design is evaluated through thermal simulation of heat pipes using various design parameters. The analysis addresses the ability of the heat exchanger to maintain engine coolant temperature at acceptable limits under different loading conditions.
2016-04-05
Technical Paper
2016-01-0188
Elankathiravan Mathivanan, Liping Liu
In the present work, the effect of various nanofluids on convective heat transfer performance in an automotive radiator was analyzed based on measured nanofluid properties. Al2O3, TiC, SiC, MWNT (multi-walled nanotube) and SiO2 nanoparticles ranging between 1 and 100 nm in size were dispersed in distilled water to form nanofluids. An ultrasonic generator was used to provide uniform particle dispersion in the fluid and keep the mixture stable for a long period of time. The impact of various particle types and their volume concentration on fluid properties such as density, thermal conductivity and viscosity were experimentally analyzed. It is observed that the nanofluid properties increased with the increase in particle volume concentration. TiO2 nanofluids were observed to show the highest increase in density (2.6% higher than the base fluid at a 1% vol. concentration) and also the largest enhancement in thermal conductivity (7.5% augmentation at 1% concentration).
2016-04-05
Technical Paper
2016-01-0187
Zizhen Yu, Gangfeng Tan, Tianming He, Xuexun Guo, MengYing Yang, Shengguang Xiong
Abstract With the improvement of occupants’ awareness on the driving safety, hydraulic retarder applications increase quickly. The traditional hydraulic retarder, on the one hand, exhausts the waste heat of transmission oil by the engine cooling system; on the other hand, the engine power should be consumed to drive the water pump and the engine cooling fan for maintaining the normal operation of the auxiliary braking system. In this study, the Organic Rankine Cycle (ORC) instead of the traditional hydraulic retarder water-cooling system is applied to achieve the effective temperature control of the hydraulic retarder, while the waste heat of transmission oil could be recovered for saving vehicle energy consumption.
2016-04-05
Journal Article
2016-01-0192
Alaa El-Sharkawy, Ahmed Uddin
Abstract Engine mount is one of the temperature sensitive components in the vehicle under-hood. Due to increasing requirements for improved fuel economy, the under-hood thermal management has become very challenging in recent years. In order to study the effects of material thermal degradation on engine mount performance and durability; it is required to estimate the temperature of engine mount rubber during various driving conditions. The effect of temperature on physical properties of natural rubber can then be evaluated and the life of engine mount can be estimated. In this paper, a bench test is conducted where the engine mount is exposed to a step change in the environment around it, and the temperature of the rubber section is recorded at several points till a steady state temperature is reached. A time response curve is generated, from which a time constant is determined.
2016-04-05
Technical Paper
2016-01-0248
Mingyu Wang, Edward Wolfe, Timothy Craig, Tim J. Laclair, Omar Abdelaziz, Zhiming Gao
Abstract Without the waste heat available from the engine of a conventional automobile, electric vehicles (EVs) must provide heat to the cabin for climate control using energy stored in the vehicle. In current EV designs, this energy is typically provided by the traction battery. In very cold climatic conditions, the power required to heat the EV cabin can be of a similar magnitude to that required for propulsion of the vehicle. As a result, the driving range of an EV can be reduced very significantly during winter months, which limits consumer acceptance of EVs and results in increased battery costs to achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs). The system uses the stored latent heat of an advanced phase change material (PCM) to provide cabin heating.
2016-04-05
Technical Paper
2016-01-0230
Gene Titov, Jason Lustbader, Daniel Leighton, Tibor Kiss
Abstract The National Renewable Energy Laboratory’s (NREL’s) CoolSim MATLAB/Simulink modeling framework was expanded by including a newly developed coolant loop solution method aimed at reducing the simulation effort for complex thermal management systems. The new approach does not require the user to identify specific coolant loops and their flow. The user only needs to connect the fluid network elements in a manner consistent with the desired schematic. Using the new solution method, a model of NREL's advanced combined coolant loop system for electric vehicles was created that reflected the test system architecture. This system was built using components provided by MAHLE Inc. and included both air conditioning and heat pump modes. Validation with test bench data and verification with the previous solution method were performed for 10 operating points spanning a range of ambient temperatures between -2°C and 43°C.
2016-04-05
Journal Article
2016-01-0760
Mark Sellnau, Matthew Foster, Wayne Moore, James Sinnamon, Kevin Hoyer, William Klemm
Abstract The second generation 1.8L Gasoline Direct Injection Compression Ignition (GDCI) engine was built and tested using RON91 gasoline. The engine is intended to meet stringent US Tier 3 emissions standards with diesel-like fuel efficiency. The engine utilizes a fulltime, partially premixed combustion process without combustion mode switching. The second generation engine features a pentroof combustion chamber, 400 bar central-mounted injector, 15:1 compression ratio, and low swirl and squish. Improvements were made to all engine subsystems including fuel injection, valve train, thermal management, piston and ring pack, lubrication, EGR, boost, and aftertreatment. Low firing friction was a major engine design objective. Preliminary test results indicated good improvement in brake specific fuel consumption (BSFC) over the first generation GDCI engines, while meeting targets for engine out emissions, combustion noise and stability.
2016-04-05
Journal Article
2016-01-0523
Lauren Abro
Abstract North American customer perception of Quality has changed over time and has shifted from Quality, Dependability, and Reliability (QDR) to Interior Sensory Quality (ISQ). ISQ is defined as the harmony of characteristics that combine to make an emotional connection to the vehicles’ interior. Vehicles need to correctly appeal to customers emotional side through providing class-leading ISQ. Hypotheses for specific interior areas were developed in order to identify key ISQ strengths, weaknesses, and preferences. These hypotheses were then tested at customer clinics held across the country. The key goals were to understand customer judgment of ISQ execution, understand customer ISQ priority, and understand customer preference of detailed component areas.
2016-04-05
Journal Article
2016-01-0521
Ronald S. Grossman
Abstract The lightweighting of auto components is a crucial strategy for OEMs to achieve increasingly challenging CAFÉ requirements. Research from MIT has found that every 10% reduction in passenger vehicle weight reduces fuel consumption by about 7%. Since fuel economy requirements have already increased by 18% from MY 2012 to 2017, the weight savings strategies that are easiest to implement have largely been exhausted. Seating is the largest interior component by weight, but the foam is often overlooked from lightweighting consideration due to the perception that higher weight, higher density seating is an important aspect of the vehicle’s comfort. It has become almost a truism that the physical properties associated with seating comfort -- load bearing, resilience, durability - are directly related to foam density. A new auxiliary blowing agent known chemically as HFO 1233zd(E) is commercially available as Solstice® LBA.
Viewing 271 to 300 of 8633