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Viewing 151 to 180 of 8633
2017-03-28
Technical Paper
2017-01-0154
Sudhi Uppuluri, Hemant R Khalane, Ajay Naiknaware
Abstract With the upcoming regulations for fuel economy and emissions, there is a significant interest among vehicle OEMs and fleet managers in developing computational methodologies to help understand the influence and interactions of various key parameters on Fuel Economy and carbon dioxide emissions. The analysis of the vehicle as a complete system enables designers to understand the local and global effects of various technologies that can be employed for fuel economy and emission improvement. In addition, there is a particular interest in not only quantifying the benefit over standard duty-cycles but also for real world driving conditions. The present study investigates impact of exhaust heat recovery system (EHRS) on a typical 1.2L naturally aspirated gasoline engine passenger car representative of the India market.
2017-03-28
Technical Paper
2017-01-0214
Simon O. Omekanda, Rezwanur Rahman, Eric M. Lott, Sadek S. Rahman, Daniel E. Hornback
Abstract Designing an efficient transient thermal system model has become a very important task in improving fuel economy. As opposed to steady-state thermal models, part of the difficulty in designing a transient model is optimizing a set of input parameters. The first objective in this work is to develop an engine compatible physics-based 1D thermal model for fuel economy and robust control. In order to capture and study the intrinsic thermo-physical nature, both generic “Three Mass” and “Eight Mass” engine models are developed. The models have been correlated heuristically using Simulink. This correlation and calibration process is challenging and time consuming, especially in the case of the 8-mass model. Hence, in this work a Particle Swarm Optimizer (PSO) method has been introduced and implemented on a simple 3-mass and more complex 8-mass engine thermal model in order to optimize the input parameters.
2017-03-28
Technical Paper
2017-01-0169
Ward J. Atkinson, William Raymond Hill, Gursaran D. Mathur
Abstract The EPA has issued regulations in the Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards (420r12901-3). This document provides credits against the fuel economy regulations for various Air Conditioning technologies. One of these credits is associated with increased use of recirculation air mode, when the ambient is over 24°C (75°F.). The authors want to communicate the experiences in their careers that highlighted issues with air quality in the interior of the vehicle cabin. Cabin contamination sources may result in safety and health issues for both younger and older drivers. Alertness concerns may hinder their ability to operate a vehicle safely.
2017-03-28
Technical Paper
2017-01-0183
Mingyu Wang, Timothy Craig, Edward Wolfe, Tim J LaClair, Zhiming Gao, Michael Levin, Danrich Demitroff, Furqan Shaikh
Abstract It is widely recognized in the automotive industry that, in very cold climatic conditions, the driving range of an Electric Vehicle (EV) can be reduced by 50% or more. In an effort to minimize the EV range penalty, a novel thermal energy storage system has been designed to provide cabin heating in EVs and Plug-in Hybrid Electric Vehicles (PHEVs) by using an advanced phase change material (PCM). This system is known as the Electrical PCM-based Thermal Heating System (ePATHS) [1, 2]. When the EV is connected to the electric grid to charge its traction battery, the ePATHS system is also “charged” with thermal energy. The stored heat is subsequently deployed for cabin comfort heating during driving, for example during commuting to and from work. The ePATHS system, especially the PCM heat exchanger component, has gone through substantial redesign in order to meet functionality and commercialization requirements.
2017-03-28
Technical Paper
2017-01-0937
David Culbertson, James Pradun, Magdi Khair, Jeff Diestelmeier
Abstract Tightening regulations throughout the world demand a reduction in fuel consumption and NOX emission levels, creating an increasing need for additional heat for SCR aftertreatment. A durable and low cost heating system is needed for vehicles with hybrid or 24Vdc electricity. Recent development efforts have resulted in much smaller and lower cost heating systems for electrical systems ranging from 400 to 24Vdc. Test results demonstrate the feasibility of reducing the size of the heater and the relationship of heater power to the amount of time required to heat the exhaust. Intelligent solid state switching enables the heater to be smaller without compromising durability.
2017-03-28
Technical Paper
2017-01-1036
Silvia Marelli, Simone Gandolfi, Massimo Capobianco
Abstract In the last few years, the effect of diabatic test conditions on compressor performance maps has been widely investigated leading some Authors to propose different correction models. The aim of the paper is to investigate the effect of heat transfer phenomena on the experimental definition of turbocharger maps, focusing on turbine performance. An experimental investigation on a small turbocharger for automotive application has been carried out and presented. The study focused onto the effects of internal heat transfer on turbine thermomechanical efficiency. The experimental campaign was developed considering the effect of different heat transfer state by varying turbine inlet temperature, oil and coolant temperature and compressor inlet pressure. An original model previously developed by the Authors is adopted for the correction of compressor steady flow maps.
2017-03-28
Technical Paper
2017-01-0782
Qian xiong, Yasuo Moriyoshi, Koji Morikawa, Yasushi takahashi, Tatsuya Kuboyama, Toshio Yamada
Abstract To understand the mechanism of the combustion by torch flame jet in a gas engine with pre-chamber and also to obtain the strategy of improving thermal efficiency by optimizing the structure of pre-chamber including the diameter and number of orifices, the combustion process was investigated by three dimensional numerical simulations and experiments of a single cylinder natural gas engine. As a result, the configuration of orifices was found to affect the combustion performance strongly. With the same orifice diameter of 1.5mm, thermal efficiency with 7 orifices in pre-chamber was higher than that with 4 orifices in pre-chamber, mainly due to the reduction of heat loss by decreasing the impingement of torch flame on the cylinder linear. Better thermal efficiency was achieved in this case because the flame propagated area increases rapidly while the flame jets do not impinge on the cylinder wall intensively.
2017-03-28
Journal Article
2017-01-0120
Yoichiro Kawamoto, Gota Ogata, Zhiwei Shan
Abstract This study reports on a new generation ECS (Ejector Cycle System) which includes a highly efficient ejector and a novel system configuration. The ejector is working as a fluid jet pump that recovers expansion energy which is wasted in the conventional refrigeration cycle decompression process, and converts the recovered expansion energy into pressure energy and raises the compressor suction pressure. Consequently, the ejector system can reduce power consumption of the compressor by using the above mentioned pressure-rising effect and improve energy efficiency of the refrigeration cycle. The ejector consists of a nozzle, a suction section, a mixing section and a diffuser. The objective of this study is to improve actual fuel economy of all vehicles by ejector technology. The previous generation ECS was reported in 2012 SAE World Congress1. Now, a new generation ECS has been successfully developed and released in the market for Mobile Air Conditioning systems as of 2013.
2017-03-28
Journal Article
2017-01-0122
Gursaran D. Mathur
Water drainage characteristics are dependent on the design of the evaporator: specifically the design of the fins and plates along with hydrophilic coating. A part of the hydrophilic coating washes off with the moisture that condenses over the evaporator core from the air-stream. Hence, water drainage characteristics of an evaporator changes with the vehicle mileage or the age of the vehicle. Since a part of the hydrophilic coating washes away, more water is retained within the evaporator at this condition. Hence, the effectiveness of the evaporator drainage deteriorates with the age of the vehicles. At this condition, the contact angle measured at the plate increases. Author has conducted an experimental study to measure the effectiveness of hydrophilic coating from evaporators taken out from arid (9 cores) and humid areas (16 cores) as a function of vehicle mileage or vehicle age. Contact angles and water retention were measured for a number of evaporators from different OEMs.
2017-03-28
Journal Article
2017-01-0147
Brian Sweetman, Ingo Schmitz, Burkhard Hupertz, Nathanael Shaw, John Goldstein
Abstract Driven by the demand to continuously reduce the development time of new vehicles, it is of critical importance to robustly develop design and packaging concepts early within a new vehicle program using CAE methods. As the underhood and underbody package is constantly getting tighter and the engine power increases, the development of a sophisticated heat protection concept requires much more attention. For many years, heat protection CAE is an integral part of the vehicle development at Ford. However, due to challenges related to transient analysis, e.g. high numerical effort, simulation of transient buoyancy driven airflow (thermal soak), and dependency on high quality thermal material properties, heat protection CAE was primarily focused on steady state vehicle operating conditions.
2017-03-28
Journal Article
2017-01-0165
Jingwei Zhu, Stefan Elbel
Abstract Expansion work recovery by two-phase ejector is known to be beneficial to vapor compression cycle performance. However, one of the biggest challenges with ejector vapor compression cycle is that the ejector cycle performance is sensitive to working condition changes which are common in many applications, including automotive AC systems. Different working conditions require different ejector geometries to achieve maximum performance. Slightly different geometries may result in substantially different COPs under the same conditions. Ejector motive nozzle throat diameter (motive nozzle restrictiveness) is one of the key parameters that can significantly affect COP. This paper presents the experimental investigation of a new motive nozzle restrictiveness control mechanism for two-phase ejectors used in vapor compression cycles, which has the advantages of being simple, potentially less costly and less vulnerable to clogging.
2017-03-28
Journal Article
2017-01-0170
Aditya Velivelli, Daniel Guerithault, Stefan Stöwe
Abstract Seat cooling and heating strategies have enhanced human thermal comfort in automotive environments. Cooling/heating strategies also need to focus on the distribution of the seat cooling/heating power across the seat and the effect of such distributions on human thermal comfort. This paper studies the effect of active cooling combined with ventilation only strategy on thermal comfort. As part of the study, heat flux between the occupant and seat is mapped and is correlated to a step increase in the occupant’s local thermal comfort of body segments in contact with seat. A human physiological model and the Berkeley comfort model were combined to determine power and optimum placement of cooling to effectively cool an occupant using a climate control seat in a warm environment. This leads to a new approach using asymmetric seat cooling to distribute cooling power resulting in improved and balanced subjective comfort than traditional climate seat and ventilation technologies.
2017-03-28
Journal Article
2017-01-0178
Mark Hepokoski, Allen Curran, Sam Gullman, David Jacobsson
Abstract Passive sensor (HVAC) manikins have been developed to obtain high-resolution measurements of environmental conditions across a representative human body form. These manikins incorporate numerous sensors that measure air velocity, air temperature, radiant heat flux, and relative humidity. The effect of a vehicle’s climate control system on occupant comfort can be characterized from the data collected by an HVAC manikin. Equivalent homogeneous temperature (EHT) is often used as a first step in a cabin comfort analysis, particularly since it reduces a large data set to a single intuitive number. However, the applicability of the EHT for thermal comfort assessment is limited since it does not account for human homeostasis, i.e., that the human body actively counter-balances heat flow with the environment to maintain a constant core temperature.
2017-03-28
Journal Article
2017-01-1305
Yucheng Liu, Jeremy Batte, Zachary Collins, Jennifer Bateman, John Atkins, Madelyn Davis, David Salley, Cindy L. Bethel, John Ball, Christopher Archibald
Abstract A robot mining system was developed by the State Space Robotic undergraduate student design team from Mississippi State University (MSU) for the 2016 NASA Robotic Mining Competition. The mining robot was designed to traverse the Martian chaotic terrain, excavate a minimum of 10 kg of Martian regolith and deposit the regolith into a collector bin within 10 minutes as part of the competition. A Systems Engineering approach was followed in proceeding with this design project. The designed mining robot consisted of two major components: (1) mechanical system and (2) control system. This paper mainly focuses on the design and assessment process of the mechanical system but will also briefly mention the control system so as to evaluate the designed robotic system in its entirety. The final designed robot consisted of an aluminum frame driven by four motors and wheels. It utilized a scoop and lifting arm subsystem for collecting and depositing Martian regolith.
2017-03-28
Journal Article
2017-01-1302
Hyung In Yun, Jae Kyu Lee, Jae Hong Choi, MyoungKwon Je, Junhyuk Kim
Abstract A sliding door is one of the car door systems, which is generally applied to the vans. Compared with swing doors, a sliding door gives comfort to the passengers when they get in or out the car. With an increasing number of the family-scale activities, there followed a huge demand on the vans, which caused growing interests in the convenience technology of the sliding door system. A typical sliding door system has negative effects on the vehicle interior package and the operating effort. Since the door should move backward without touching the car body, the trajectory of the center rail should be a curve. The curve-shaped center rail infiltrates not only the passenger shoulder room, but also the opening flange curve, which results in the interior package loss. Moreover, as the passenger pulls the door outside handle along the normal direction of the door outer skin, the curved rail causes the opening effort loss.
2017-03-28
Journal Article
2017-01-1520
Teddy Hobeika, Peter Gullberg, Simone Sebben, Lennart Lofdahl
Abstract Quantification of heat exchanger performance in its operative environment is in many engineering applications an essential task, and the air flow rate through the heat exchanger core is an important optimizing parameter. This paper explores an alternative method for quantifying the air flow rate through compact heat exchangers positioned in the underhood of a passenger car. Unlike conventional methods, typically relying on measurements of direct flow characteristics at discrete probe locations, the proposed method is based on the use of load-cells for direct measurement of the total force acting on the heat exchanger. The air flow rate is then calculated from the force measurement. A direct comparison with a conventional pressure based method is presented as both methods are applied on a passenger car’s radiator tested in a full scale wind tunnel using six different grill configurations.
2017-03-28
Journal Article
2017-01-0266
Shervin Shoai Naini, Junkui (Allen) Huang, Richard Miller, John R. Wagner, Denise Rizzo, Scott Shurin, Katherine Sebeck
Designing an efficient cooling system with low power consumption is of high interest in the automotive engineering community. Heat generated due to the propulsion system and the on-board electronics in ground vehicles must be dissipated to avoid exceeding component temperature limits. In addition, proper thermal management will offer improved system durability and efficiency while providing a flexible, modular, and reduced weight structure. Traditional cooling systems are effective but they typically require high energy consumption which provides motivation for a paradigm shift. This study will examine the integration of passive heat rejection pathways in ground vehicle cooling systems using a “thermal bus”. Potential solutions include heat pipes and composite fibers with high thermal properties and light weight properties to move heat from the source to ambient surroundings.
2017-03-28
Journal Article
2017-01-0388
Haeyoon Jung, MiYeon Song, Sanghak Kim
Abstract CO2 emission is more serious in recent years and automobile manufacturers are interested in developing technologies to reduce CO2 emissions. Among various environmental-technologies, the use of solar roof as an electric energy source has been studied extensively. For example, in order to reduce the cabin ambient temperature, automotive manufacturers offer the option of mounting a solar cell on the roof of the vehicle [1]. In this paper, we introduce the semi-transparent solar cell mounted on a curved roof glass and we propose a solar energy management system to efficiently integrate the electricity generated from the solar roof into internal combustion engine (ICE) vehicles. In order to achieve a high efficiency solar system in different driving, we improve the usable power other than peak power of solar roof. Peak power or rated power is measured power (W) in standard test condition (@ 25°C, light intensity of 1000W/m2(=1Sun)).
2017-03-28
Technical Paper
2017-01-1412
Christopher H. Goddard, David Price
Abstract Various mechanisms have been used to drive speedometers and other instrument gauges. This paper reviews the mechanisms used; in particular investigates the ability of stepper motors which have become the most common instrument motor in the last decade to freeze at the apparent reading prior to impact. Stepper motors require power to drive the needle to any indicated position, including having to return it to zero. Hence if power to the instrument is lost as a result of a collision, there is no power to move the needle and it should be left at the reading shown at the moment the power was lost. However, not all stepper motor instruments are the same and before accepting the reading, a number of criteria need to be considered to give a level of confidence in the result. As part of recent ITAI (Institute of Traffic Accident Investigators) crash test events in the UK, a number of instrument clusters were installed in vehicles to simulate both frontal and side impacts.
2017-03-28
Technical Paper
2017-01-0172
Suhas Venkatappa, Manfred Koberstein, Zhengyu Liu
Abstract The refrigerant transition from HFC-134a to HFO-1234yf has proven to be more challenging on controlling refrigerant flow-induced noises generated from automotive air-conditioning (A/C) systems than originally anticipated. The objectives of this paper are to describe the noise issues with HFO-1234yf, understand the mechanisms and key factors affecting HFO-1234yf refrigerant flow-induced noise. Finally, the countermeasures and guidelines for attenuating and suppressing the noise are presented.
2017-03-28
Technical Paper
2017-01-1391
Heather Bronczyk, Michael Kolich, Marie-Eve Cote
Abstract Load deflection testing is one type of test that can be used to understand the comfort performance of a complete trimmed automotive seat. This type of testing can be conducted on different areas of the seat and is most commonly used on the seatback, the seat cushion and the head restraint. Load deflection data can be correlated to a customer’s perception of the seat, providing valuable insight for the design and development team. There are several variables that influence the results obtained from this type of testing. These can include but are not limited to: seat structure design, suspension system, component properties, seat materials, seat geometry, and test set-up. Set-up of the seat for physical testing plays a critical role in the final results. This paper looks at the relationship of the load deflection data results on front driver vehicle seatbacks in a supported and unsupported test set-up condition.
2017-03-28
Journal Article
2017-01-0722
Pablo Olmeda, Jaime Martin, Antonio Garcia, David Villalta, Alok Warey, Vicent Domenech
Abstract Growing awareness about CO2 emissions and their environmental implications are leading to an increase in the importance of thermal efficiency as criteria to design internal combustion engines (ICE). Heat transfer to the combustion chamber walls contributes to a decrease in the indicated efficiency. A strategy explored in this study to mitigate this efficiency loss is to promote low swirl conditions in the combustion chamber by using low swirl ratios. A decrease in swirl ratio leads to a reduction in heat transfer, but unfortunately, it can also lead to worsening of combustion development and a decrease in the gross indicated efficiency. Moreover, pumping work plays also an important role due to the effect of reduced intake restriction to generate the swirl motion. Current research evaluates the effect of a dedicated injection strategy to enhance combustion process when low swirl is used.
2017-03-28
Journal Article
2017-01-0130
Phillip Bonkoski, Amey Y. Karnik, Adrian Fuxman
Abstract Control of vehicle powertrain thermal management systems is becoming more challenging as the number of components is growing, and as a result, advanced control methods are being investigated. Model predictive control (MPC) is particularly interesting in this application because it provides a suitable framework to manage actuator and temperature constraints, and can potentially leverage preview information if available in the future. In previous SAE publications (2015-01-0336 and 2016-01-0215), a robust MPC control formulation was proposed, and both simulation and powertrain thermal lab test results were provided. In this work, we discuss the controller deployment in a vehicle; where controller validation is done through road driving and on a wind tunnel chassis dynamometer. This paper discusses challenges of linear MPC implementation related to nonlinearities in this over-actuated thermal system.
2017-03-28
Journal Article
2017-01-0625
Yen-Chung Liu, Brian Sangeorzan, Alex Alkidas
Abstract The purpose of this research was to measure and correlate the area-average heat transfer coefficients for free, circular upward-impinging oil-jets onto two automotive pistons having different undercrown shapes and different diameters. For the piston heat transfer studies, two empirical area-average Nusselt number correlations were developed. One was based on the whole piston undercrown surface area with the Nusselt number based on the nozzle diameter, and the other was based on the oil-jet impingement area with the Nusselt number based on the oil-jet effective impingement diameter. The correlations can predict the 95% and 94% of the experimental measurements within 30% error, respectively. The first correlation is simpler to use and can be employed for cases in which the oil jet wets the whole piston undercrown. The latter may be more useful for larger pistons or higher Prandtl number conditions in which the oil jet wets only a portion of the undercrown.
2017-03-28
Journal Article
2017-01-0622
Sury Janarthanam, Sarav Paramasivam, Patrick Maguire, James Gebbie, Douglas Hughes
Abstract Hybrid Electric Vehicles (HEV) utilize a High Voltage (HV) battery pack to improve fuel economy by maximizing the capture of vehicle kinetic energy for reuse. Consequently, these HV battery packs experience frequent and rapid charge-discharge cycles. The heat generated during these cycles must be managed effectively to maintain battery cell performance and cell life. The HV battery pack cooling system must keep the HV battery pack temperature below a design target value and maintain a uniform temperature across all of the cells in the HV battery pack. Herein, the authors discuss some of the design points of the air cooled HV battery packs in Ford Motor Company’s current model C-Max and Fusion HEVs. In these vehicles, the flow of battery cooling air was required to not only provide effective cooling of the battery cells, but to simultaneously cool a direct current high voltage to low voltage (DC-DC) converter module.
2017-03-28
Journal Article
2017-01-1046
Christian Binder, Fahed Abou Nada, Mattias Richter, Andreas Cronhjort, Daniel Norling
Abstract Diesel engine manufacturers strive towards further efficiency improvements. Thus, reducing in-cylinder heat losses is becoming increasingly important. Understanding how location, thermal insulation, and engine operating conditions affect the heat transfer to the combustion chamber walls is fundamental for the future reduction of in-cylinder heat losses. This study investigates the effect of a 1mm-thick plasma-sprayed yttria-stabilized zirconia (YSZ) coating on a piston. Such a coated piston and a similar steel piston are compared to each other based on experimental data for the heat release, the heat transfer rate to the oil in the piston cooling gallery, the local instantaneous surface temperature, and the local instantaneous surface heat flux. The surface temperature was measured for different crank angle positions using phosphor thermometry.
2017-03-28
Technical Paper
2017-01-0192
Antti Lajunen
Abstract The energy used for cabin cooling and heating can drastically reduce the operating range of electric vehicles. The energy efficiency and performance of the cabin heating, ventilation and air conditioning (HVAC) system depend on the system configuration and ambient conditions. The presented research investigates the energy efficiency and performance of cabin thermal management in electric vehicles. A simulation model of cabin heating and cooling systems was developed in the AMESim software. Simulations were carried out in the standard test cycles and one real-world driving cycle to take into account different driving behaviors and environments. The cabin thermal management performance was analyzed in relation to ambient temperature, system efficiency and cabin thermal balance. The simulation results showed that the driving range can shorten more than 50% in extreme cold conditions.
2017-03-28
Technical Paper
2017-01-0491
Hyerin Choi, Jaeyong Ko, JunHo Song, SeungKeon Woo
Abstract Recently, it is one of a major problems in automotive industry that wrinkles on seat interior occur at detaching between seat covering and padding foam. The purpose of this research is the way to improve heat resistance and adhesion using polyurethane reactive (PUR) of thermosetting plastic material. We compose PUR that makes thin film and non-tacky characteristic on padding foam. We find optimum situation (method and amount) for leather and padding foam. Viscosity and melting temperature are adjusted to coat with amount. 25~30g/m2 are suitable on padding foam unlike traditional method to coat leather above 100g/ m2. We also verified performances of PUR lamination compared to others. As result, peel strength is strongest at 15.4N/30mm. Heat resistance is also excellent with various padding foams. Furthermore we advance an additional jig to match leather and padding foam by low tacky characteristic of PUR. This jig can increase productivity in seat manufacturing process.
2017-03-28
Technical Paper
2017-01-1389
Ankush Kamra, Sandeep Raina, Pankaj Maheshwari, Abhishek Agarwal, Prasad Latkar
Abstract Automotive seating is designed by considering safety, comfort and aesthetics for the occupants. Seating comfort is one of the important parameters for the occupant for enhancing the overall experience in a vehicle. Seating comfort is categorized as static (or showroom) comfort and dynamic comfort. The requirements for achieving static and dynamic comfort can sometimes differ and may require design parameters such as PU hardness to be set in opposite directions. This paper presents a case wherein a base seat with good dynamic comfort is taken and an analysis is done to improve upon the static comfort, without compromising on the dynamic comfort. The study focuses on improving the initial comfort by considering various options for seating upholstery.
2017-03-28
Technical Paper
2017-01-1393
Georges Beurier, Michelle Cardoso, Xuguang Wang
Abstract A new experimental seat was designed to investigate sitting biomechanics. Previous literature suggested links between sitting discomfort and shear force, however, research on this topic is limited. The evaluation of sitting discomfort derived from past research has been primarily associated with seat pressure distribution. The key innovative feature of the experimental seat is not only pressure distribution evaluation but shear forces as well. The seat pan of the experimental seat compromises of a matrix of 52 cylinders, each equipped with a tri-axial force sensor, enabling us to measure both normal and tangential forces. The position of each cylinder is also adjustable permitting a uniform pressure distribution underneath the soft tissue of the buttocks and thighs. Backrest, armrests, seat pan and flooring are highly adjustable and equipped with forces sensors to measure contact forces.
Viewing 151 to 180 of 8633