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2017-03-28
Technical Paper
2017-01-0275
N. Obuli Karthikeyan, N. Prajitha, P. Sethu Madhavan
Abstract As technology gets upgraded every day, automotive manufacturers are paying more attention towards delivering a highly reliable product which performs its intended function throughout its useful life (without any failure). To develop a reliable product, accelerated combined stress testing should be conducted in addition to the conventional design validation protocol for the product. It brings out most of the potential failure modes of the product, so that necessary actions can be taken for the reliability improvement. This paper discusses about the field failure simulation and reliability estimation of automotive headlamp relays using accelerated combined stress testing. To analyze various field failure modes, performance and tear down analysis were carried out on the field failure samples. Field data (i.e. electrical, thermal and vibration signals) were acquired to evaluate normal use conditions.
2017-03-28
Technical Paper
2017-01-0363
Karthik Ramaswamy, Vinay L. Virupaksha, Jeanne Polan, Biswajit Tripathy
Abstract Expanded Polypropylene (EPP) foams are most commonly used in automotive applications for pedestrian protection and to meet low speed bumper regulatory requirements. In today’s automotive world the design of vehicles is predominantly driven by Computer Aided Engineering (CAE). This makes it necessary to have a validated material model for EPP foams in order to simulate and predict performance under various loading conditions. Since most of the automotive OEMs depend on local material suppliers for their global vehicle applications it is necessary to understand the variation in mechanical properties of the EPP foams and its effect on performance predictions. In this paper, EPP foams from three suppliers across global regions are characterized to study the inter-supplier variation in mechanical properties.
2017-03-28
Technical Paper
2017-01-0143
Neelakandan Kandasamy, Steve Whelan
Abstract During cabin warm-up, effective air distribution by vehicle climate control systems plays a vital role. For adequate visibility to the driver, major portion of the air is required to be delivered through the defrost center ducts to clear the windshield. HVAC unit deliver hot air with help of cabin heater and PTC heater. When hot air interacts with cold windshield it causes thermal losses, and windshield act as sink. This process may causes in delay of cabin warming during consecutive cabin warming process. Thus it becomes essential to predict the effect of different windscreen defrost characteristics. In this paper, sensitivity analysis is carried for different windscreen defrosts characteristics like ambient conditions, modes of operation; change in material properties along with occupant thermal comfort is predicted. An integrated 1D/3D CFD approach is proposed to evaluate these conditions.
2017-03-28
Technical Paper
2017-01-1737
Piyapong Premvaranon, Jenwit Soparat, Apichart Teralapsuwan, Sutee Olarnrithinun
Abstract Beyond the modern design and illumination quality of automotive lamps, thermal management plays a crucial role and must be fulfilled in the early stages of the design process. An excessive thermal radiation from incandescent bulb can cause a severe thermal degradation of plastic parts such as housing or optical lens. Hence, to assess such impact of heat on the plastic parts, thermal analysis of a license plate lamp was investigated by a proposed technique combining computational fluid dynamics (CFD) and ray tracing mapping method. Then, the accuracy and computational cost of the method were compared with thermal results obtained by a thermal radiation model using Monte Carlo (MC) technique for calculating radiation effect coupled with CFD in heat transfer analysis. Finally, a comparison of temperature results from both techniques were validated with practical thermal measurements of license plate lamp prototype.
2017-03-28
Technical Paper
2017-01-0508
Gabor Kiss, Yuya Ando, Martin Schifko
Abstract Simulation tools are becoming more and more popular in the automotive industry since they can significantly reduce the costs required for development of new models. Currently there are many computational fluid dynamics (CFD) tools available on the market and becoming indispensable tools for R&D in many of the automotive applications. However there are some applications which require much effort by highly skilled engineers to prepare the model and impractical level of computation time even using a cluster computer using the conventional CFD tools due to the nature of physics and complexity of a geometry such like dip painting process. Therefore, corrosion protection engineers are striving to find an alternative solution. Another issue is that the main focus of those available CFD tools are problems occurring during the dip paint simulations and they omit problems occurring after the object dips out from the bath, such as retained water or bake drips.
2017-03-28
Technical Paper
2017-01-0507
Christian K. Riener, Anna-Elisabeth Raab, Gerald Luckeneder, Martin Rosner
Abstract Zinc-coatings with a substantial Magnesium content have been in use for over 30 years by now. Unlike the well-established Zn-Al-Mg coatings originating from Japan which have significant higher alloying contents applied mainly for building applications, this Zinc Magnesium Aluminum coating (ZM) is also specifically designed to meet the requirements of car manufacturers. The ZM coating introduced by voestalpine, corrender, is in the upper range of ZM-alloying compositions, which was set by VDA (German Association of the Automotive Industry) and SAE to be within 1.0 to 2.0 wt. % Mg and 1.0 to 3.0 wt. % Al. The properties of these “European” Zinc-Magnesium coatings are well comparable within this range. Compared to GI and GA ZM coatings exhibit significant advantages in the press shops with its excellent formability and reduced galling and powdering respectively which is a significant advantage for the forming of outer panels.
2017-03-28
Journal Article
2017-01-1306
Michael Ulizio, DeWitt Lampman, Mukesh Rustagi, Jason Skeen, Chester Walawender
Abstract Automotive manufacturers are requiring lightweight materials, including glazing materials to improve vehicle fuel economy mandates. Since windshields are one of the largest glazing surface areas, reducing the thickness of the glass in its construction can significantly provide weight savings opportunities. Automotive glazing design considerations must include overall glass strength, rigidity, acoustical, and solar performance, which are affected by changes of glass thicknesses. This paper will evaluate those design considerations in the lightweighting of windshield glazings. One important design consideration for the windshield position is the impact of debris from the environment. Lightweighting of glazings in this body position affects the way the construction reacts to an impact. Use of asymmetry in glass plies in a laminated construction can have a marked effect on the part’s impact performance and surface damage creation.
2017-03-28
Journal Article
2017-01-1513
Young-Chang Cho, Chin-Wei Chang, Andrea Shestopalov, Edward Tate
Abstract The airflow into the engine bay of a passenger car is used for cooling down essential components of the vehicle, such as powertrain, air-conditioning compressor, intake charge air, batteries, and brake systems, before it returns back to the external flow. When the intake ram pressure becomes high enough to supply surplus cooling air flow, this flow can be actively regulated by using arrays of grille shutters, namely active grille shutters (AGS), in order to reduce the drag penalty due to excessive cooling. In this study, the operation of AGS for a generic SUV-type model vehicle is optimized for improved fuel economy on a highway drive cycle (part of SFTP-US06) by using surrogate models. Both vehicle aerodynamic power consumption and under-hood cooling performance are assessed by using PowerFLOW, a high-fidelity flow solver that is fully coupled with powertrain heat exchanger models.
2017-03-28
Journal Article
2017-01-1543
Jonathan Jilesen, Adrian Gaylard, Jose Escobar
Abstract Vehicle rear and side body soiling has been a concern since the earliest cars. Traditionally, soiling has been seen to be less importance than vehicle aerodynamics and acoustics. However, increased reliance on sensors and cameras to assist the driver means that there are more surfaces of the vehicle that must be kept clean. Failure to take this into consideration means risking low customer satisfaction with new features. This is because they are likely to fail under normal operating conditions and require constant cleaning. This paper numerically investigates features known to have an influence on side and rear face soiling with a demonstration vehicle. These changes include rim design, diffuser strakes and diffuser sharpening. While an exhaustive investigation of these features is beyond the scope of this study, examples of each feature will be considered.
2017-03-28
Technical Paper
2017-01-1538
Jiaye Gan, Longxian Li, Gecheng Zha, Craig Czlapinski
Abstract This paper conducts numerical simulation and wind tunnel testing to demonstrate the passive flow control jet boat tail (JBT) drag reduction technique for a heavy duty truck rear view mirror. The JBT passive flow control technique is to introduce a flow jet by opening an inlet in the front of a bluff body, accelerate the jet via a converging duct and eject the jet at an angle toward the center of the base surface. The high speed jet flow entrains the free stream flow to energize the base flow, increase the base pressure, reduces the wake size, and thus reduce the drag. A baseline heavy duty truck rear view mirror is used as reference. The mirror is then redesigned to include the JBT feature without violating any of the variable mirror position geometric constraints and internal control system volume requirement. The wind tunnel testing was conducted at various flow speed and yaw angles.
2017-03-28
Technical Paper
2017-01-1529
Nicholas Simmonds, John Pitman, Panagiotis Tsoutsanis, Karl Jenkins, Adrian Gaylard, Wilko Jansen
Abstract Cooling drag, typically known as the difference in drag coefficient between open and closed cooling configurations, has traditionally proven to be a difficult flow phenomenon to predict using computational fluid dynamics. It was seen as an academic yardstick before the advent of grille shutter systems. However, their introduction has increased the need to accurately predict the drag of a vehicle in a variety of different cooling configurations during vehicle development. This currently represents one of the greatest predictive challenges to the automotive industry due to being the net effect of many flow field changes around the vehicle. A comprehensive study is presented in the paper to discuss the notion of defining cooling drag as a number and to explore its effect on three automotive models with different cooling drag deltas using the commercial CFD solvers; STARCCM+ and Exa PowerFLOW.
2017-03-28
Technical Paper
2017-01-1531
Keiichi Taniguchi, Akiyoshi Shibata, Mikako Murakami, Munehiko Oshima
Abstract This paper describes a study of drag reduction devices for production pick-up trucks with a body-on-frame structure using full-scale wind tunnel testing and Computational Fluid Dynamics (CFD) simulations. First, the flow structure around a pick-up truck was investigated and studied, focusing in particular on the flow structure between the cabin and tailgate. It was found that the flow structure around the tailgate was closely related to aerodynamic drag. A low drag flow structure was found by flow analysis, and the separation angle at the roof end was identified as being important to achieve the flow structure. While proceeding with the development of a new production model, a technical issue of the flow structure involving sensitivity to the vehicle velocity was identified in connection with optimization of the roof end shape. (1)A tailgate spoiler was examined for solving this issue.
2017-03-28
Technical Paper
2017-01-1417
Enrique Bonugli, Richard Watson, Mark Freund, Jeffrey Wirth
Abstract This paper reports on seventy additional tests conducted using a mechanical device described by Bonugli et al. [4]. The method utilized quasi-static loading of bumper systems and other vehicle components to measure their force-deflection properties. Corridors on the force-deflection plots, for various vehicle combinations, were determined in order to define the system stiffness of the combined vehicle components. Loading path and peak force measurements can then be used to evaluate the impact severity for low speed collisions in terms of delta-v and acceleration. The additional tests refine the stiffness corridors, previously published, which cover a wide range of vehicle types and impact configurations. The compression phase of a low speed collision can be modeled as a spring that is defined by the force-deflection corridors. This is followed by a linear rebound phase based on published restitution values [1,5].
2017-03-28
Technical Paper
2017-01-1356
Rainer Neumann
Abstract In the last years we recognize a big amount of innovative solutions in the field of automotive lighting and especially in front lighting systems. The major target to improve the light performance and to make driving at night safe is most important. The measure for the performance rating and the ability to compare different systems with a technology neutral process seems to be quite difficult. The legislation is looking for a simplification with clearly defined parameters for the future. Experimental test series recently published causing a lot of discussions as the sensitivity of the aiming of the headlamps can cause completely different performance test results. The paper will report on a study with various production vehicles, all in the same way initially aimed and prepared for all type of technologies.
2017-03-28
Technical Paper
2017-01-1358
Hyunbin Park
Abstract This paper presents a novel rear-view side mirror constructed with an external lens and a planar mirror to improve aerodynamics and minimize the blind spot of drivers. To resolve the drawback of the conventional side mirror, some vehicle manufacturers have lately attempted to develop a camera-based solution to replace traditional protruding side mirrors. However, driving vehicles on public roads without such side mirrors is illegal in most countries including the USA. The United States Federal Motor Vehicle Safety Standards (FMVSS) specifies that the mirror installed on the driver side should be flat and should have unit magnification. The proposed system avoids the large, protruding, external side-mirror that is currently used in present-day vehicles. Instead, it integrates this external element into the interior of the vehicle to improve aerodynamic resistance, safety, and styling.
2017-03-28
Technical Paper
2017-01-1365
Michael Larsen
Abstract Vehicle certification requirements generally fall into 2 categories: self-certification and various forms of type approval. Self-certification requirements used in the United States under Federal Motor Vehicle Safety Standards (FMVSS) regulations must be objective and measurable with clear pass / fail criteria. On the other hand, Type Approval requirements used in Europe under United Nations Economic Commission for Europe (UNECE) regulations can be more open ended, relying on the mandated 3rd party certification agency to appropriately interpret and apply the requirements based on the design and configuration of a vehicle. The use of 3rd party certification is especially helpful when applying regulatory requirements for complex vehicle systems that operate dynamically, changing based on inputs from the surrounding environment. One such system is Adaptive Driving Beam (ADB).
2017-03-28
Technical Paper
2017-01-1366
Jeffrey Muttart, Swaroop Dinakar, Jeffrey Suway, Michael Kuzel, Timothy Maloney, Wayne Biever, Toby Terpstra, Tilo Voitel, David Cavanaugh, T.J. Harms
Abstract Collision statistics show that more than half of all pedestrian fatalities caused by vehicles occur at night. The recognition of objects at night is a crucial component in driver responses and in preventing nighttime pedestrian accidents. To investigate the root cause of this fact pattern, Richard Blackwell conducted a series of experiments in the 1950s through 1970s to evaluate whether restricted viewing time can be used as a surrogate for the imperfect information available to drivers at night. The authors build on these findings and incorporate the responses of drivers to objects in the road at night found in the SHRP-2 naturalistic database. A closed road outdoor study and an indoor study were conducted using an automatic shutter system to limit observation time to approximately ¼ of a second. Results from these limited exposure time studies showed a positive correlation to naturalistic responses, providing a validation of the time-limited exposure technique.
2017-03-28
Technical Paper
2017-01-1368
Jeffrey Aaron Suway, Steven Suway
Abstract Mapping the luminance values of a visual scene is of broad interest to accident reconstructionists, human factors professionals, and lighting experts. Such mappings are useful for a variety of purposes, including determining the effectiveness and appropriateness of lighting installations, and performing visibility analyses for accident case studies. One of the most common methods for mapping luminance is to use a spot type luminance meter. This requires individual measurements of all objects of interest and can be extremely time consuming. Luminance cameras can also be used to create a luminance map. While luminance cameras will map a scene’s luminance values more quickly than a spot luminance meter, commercially available luminance cameras typically require long capture times during low illuminance (up to 30 seconds). Previous work has shown that pixel intensity captured by consumer-grade digital still cameras can be calibrated to measure luminance.
2017-03-28
Technical Paper
2017-01-1359
Michael Hamm
Abstract Headlamp performance has changed in the last 20 years significantly. Sealed beam lamps were replaced by VHAD, VOR and VOL types, but still the optical input in terms of tungsten filament based luminous flux remained more stable. With Xenon discharge lamps and now LED the performance of a headlamp may vary strongly and thus the optical performance. Various rating systems have been developed to assess the quality of lamps and light distribution, some based on laboratory based data, some based on static or dynamic street test drives with online measurements and assessments. Basic interest is to understand the performance of the light for a real driver. This article will discuss the influence parameters on achieving a repeatable and precise rating as well as the outer influence that creates glare and varying seeing distance. Mostly mechanical headlamp and car conditioning will influence the result as well as human factors like aiming precision and aiming tolerances.
2017-03-28
Technical Paper
2017-01-1369
Abtine Tavassoli, Sam Perlmutter, Dung Bui, James Todd, Laurene Milan, David Krauss
Abstract Vision plays a key role in the safe and proper operation of vehicles. To safely navigate, drivers constantly scan their environments, which includes attending to the outside environment as well as the inside of the driver compartment. For example, a driver may monitor various instruments and road signage to ensure that they are traveling at an appropriate speed. Although there has been work done on naturalistic driver gaze behavior, little is known about what information drivers glean while driving. Here, we present a methodology that has been used to build a database that seeks to provide a framework to supply answers to various ongoing questions regarding gaze and driver behavior. We discuss the simultaneous recording of eye-tracking, head rotation kinematics, and vehicle dynamics during naturalistic driving in order to examine driver behavior with a particular focus on how this correlates with gaze behavior.
2017-03-28
Technical Paper
2017-01-1361
Huan-Ping Chiu, Gerald Uhlenberg, Alex Wang, Jung Hsien Yen
Abstract In this study, we are presenting design considerations for the development of a LED (Light-Emitting Diode) bi-function headlight module to replace conventional HID (High-Intensity Discharge) projector modules for retrofitting or first installation purposes. The objective was to develop a projector-type module to outperform current 35 W HID light sources in both low beam and high beam, but with far less installation space. Essential features like multichip LED usage and the optical system design will be described in detail. Special care was taken for the heat management of the high-power LEDs, with optimization of the heat dissipation thermal path via printed circuit board, heatsink and active cooling by extensive Computational Fluid Dynamics simulation work (CFD). The achieved projector lumen output of greater 1300 lm in low beam and 2000 lm in high beam enables a projector module of very compact size (<1,200 cm3) to easily replace HID modules.
2017-03-28
Technical Paper
2017-01-1360
John D. Bullough
Abstract Nighttime driving cannot be accomplished without vehicle headlighting. A growing body of evidence demonstrates the role of lighting on visual performance and in turn on nightttime driving safety in terms of crashes. Indirect impacts of lighting via comfort or other factors are less well understood, however. A two-part field study using real-world drivers of an instrumented vehicle was conducted to assess the potential role of oncoming headlight glare as a factor in driving behaviors that might be related to increased crash risks. In the first part of the study, drivers' behaviors when navigating through roadway intersections having different levels of crash risk were recorded in order to identify responses that were correlated with the risk level. In the second part, drivers were exposed to different levels of glare from oncoming headlights; several of the same risk-related behaviors identified in the first part of the study were exhibited.
2017-03-28
Technical Paper
2017-01-1364
Kashif Ali, Vikas Kumar, Virat Kalra
Abstract Vehicle occupant packaging and interior and exterior body design determine the overall visibility that the driver of the vehicle has. Visibility is also dependent on technological features inside and outside the passenger cell like proximity sensors and cameras etc. The focus of this research is to find and analyze the visibility percentages, blind spot angles and blind spot areas using statistical data both individually and as vehicle class put together in order to justify the need for standardization of basic visibility enhancing aids. This study has an added significance considering the Indian road transportation statistics. On an average, 16 people die every hour due to road accidents in India. The aim is to focus on cases that affect visibility in low speed driving, coasting and reversing that causes loss to public and private property.
2017-03-28
Technical Paper
2017-01-1370
Hiroyuki Hara, Masaaki Kawauchi, Masayuki Katayama, Noriyuki Iwamori
Abstract Driving is an action that depends strongly on visual information. For displays in the cockpit, a combination of “ease of viewing” to inform the driver of danger early and “annoyance reduction” to avoid drops in the driver’s perception is needed. In this study, we tried to capture “ease of viewing” and “annoyance” in one fixed-quantity indicator. We took up a Camera Monitor System (CMS) as the subject and analyzed the effect that annoyance with the display used in CMSs has on driving behavior. Based on our analysis, we hypothesize that evaluating carelessness in viewing behavior is related evaluating to annoyance. Next, we chose a Detection Response Task (DRT) technique as a method to evaluate driving behavior influenced by this annoyance.
2017-01-10
Technical Paper
2017-26-0221
Swamy Mukkera, Aditya Pandey, Kodali Ajay Krishna, Sanjeev Patil, P L N Prasad
Abstract Wind noise is becoming important for automotive development due to significant reductions in road and engine noise. This aerodynamic noise is dominant at highway speeds and contributes towards higher frequency noise (>250Hz). In automotive industry accurate prediction and control of noise sources results in improved customer satisfaction. The aerodynamic noise prediction and vehicle component design optimization is generally executed through very expensive wind tunnel testing. Even with the recent advances in the computational power, predicting the flow induced noise sources is still a challenging and computationally expensive problem. A typical case of fluid-solid interaction at higher speeds results into broadband noise and it is inherently an unsteady phenomenon. To capture such a broad range of frequency, Detached Eddy Simulation (DES) has been proven to be the most practical and fairly accurate technique as sighted in literature.
2017-01-10
Technical Paper
2017-26-0207
Dayal Mirthinti, Dinesh Sahrawat, Rohit Dang
Abstract In automobile, NVH has been playing an important role in defining the overall quality of the vehicle. Continuous efforts are being put in globally by engineers to make the travel experience as comfortable as possible for both commercial and passenger segment vehicles. The front wiping system being a critical safety feature in an automobile is one of the sources of structural vibrations/noise due to numerous moving child parts. Therefore, the layout of the wiper motor in the vehicle is an important aspect of Vehicle NVH. These vibrations and noise levels become more pronounced if the wiper motor is mounted inside the passenger compartment, a layout that is commonly seen in commercial vehicles. This paper focuses on measures to improve the NVH while having the layout of the wiping system inside the passenger compartment of the vehicle.
2017-01-10
Technical Paper
2017-26-0257
Mandar Bhatkhande, Rahul Mahajan, Amol Joshi
Abstract Front windscreen wiping test is legal requirement for all motor vehicles as per standards like IS15802:2008 [1], IS15804:2008 [2] in India. This test requires windscreen mock-up/actual vehicle to be tested along with all wiping mechanisms such that minimum percentage areas to be wiped should meet the requirements specified in the IS standard. From manufacturer’s perspective this involves investment of lot of time and cost to arrive at the final design solution in order to meet the wiping requirements. The work scope in this paper is limited to bus category of vehicles. The methodology presented in this paper would enable quick design solutions for bus body builders or manufacturers to meet the wiping requirements specified in IS standard. The methodology presented in this paper was developed to carry out windscreen wiping test through commercially available simulation software.
2017-01-10
Technical Paper
2017-26-0007
Siva Murugesan, Vishakha S Bhagat, B V Shamsundara, Abhay Mannikar
Abstract In year 2015, 17 people were killed every hour by road accidents in India [1]. The occurrence of road accidents is observed to be higher during night, when visibility is at its lowest. The two factors which affect visibility are insufficient illumination and glare caused by the oncoming traffic. The Adaptive Front Lighting System [AFS] is an active safety feature which addresses these problems by employing specific lighting modes for Town, Country, Expressway conditions and automatic switching between Driving Beam and Passing Beam whenever required. Matrix of LEDs or a Projector with an actuator or a combination of both is employed in achieving different Lighting modes. The projector based AFS module is preferred for implementing the AFS control logic for passing beam owing to its economic cost.
2017-01-10
Technical Paper
2017-26-0322
Saktheeswaran Kasinathan, Sreenivasa Gupta, Husain Agha, Rajiv Modi
Abstract In any industry, early detection and mitigation of a failure in component is vital for feasible design changes or development iterations or saving money. So it becomes pivotal to capture the failure mode in an accelerated way. This theory poses many challenges in devising the methodology to validate the failure mode. In real world, vehicle head lamp is exposed to all possible kinds of harsh environments such as variable daily ambient, rain, dust and engine compartment temperature …etc. This brings rapid thermal stress onto headlamp resulting into warpage cracks. At vehicle level on particular model, this failure is typically observed after 20,000-25,000 kms in a span of 3-4 months of running. Any corrective action to revalidate the design change or improvement will need similar timelines in regular way to test, which is quite high in product development cycle.
2017-01-10
Technical Paper
2017-26-0325
Anup Batra, Sreenivasa Gupta, Husain Agha, K Rajakumar, Rajiv Modi
Abstract With the advancement in vehicle technology over the years, many intuitive technologies are coming in automotive passenger vehicles to improve the safety aspects during vehicle driving in night conditions. In addition to headlamps, cornering lamps or infrared camera with head up display etc. are evolving as a part of AFS (Advanced Front Lighting Systems) to aid driver vision. Many OEMs are following conventional methodology of subjective assessments with the ratings on different numerical scale mapped with customer acceptance to validate head lamps and its tech updates. These methods lag in getting repeatability of results, acceptance reliability and not knowing the limitations of the installed system due to high dependency on the selected evaluators. This paper emphasizes on robust test methodology development to validate the complete performance of cornering lamps with the objective test data analysis.
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