Criteria

Text:
Sector:
Display:

Results

Viewing 1 to 30 of 19859
2018-04-13
Journal Article
2018-01-9178
Helena Martini, Peter Gullberg, Lennart Lofdahl
This paper deals with the analysis of cooling airflow for two different front-end designs of a heavy truck. The first design is a cab-over-engine (COE) cab; the second is a Soft Nose (SN) cab, which in this case is basically an elongation of the grille area of the COE cab to obtain a smoother shape of the cab. The SN model used in this investigation was extended 200mm from the COE front. Computational Fluid Dynamics (CFD) was used as the tool for examining the aerodynamic properties of the vehicle models. The configurations were evaluated both with inactive and active heat exchangers, in order to examine the effect of heating the air on the drag co-efficient and also to determine the cooling capacity of the different models. A sub- study was performed where different opening percentages of the grille area was investigated to determine the minimum percentage opening that would be needed to achieve a radiator Top Tank Temperature (TTT) value below a target limit of 100°C.
2018-04-03
Technical Paper
2018-01-0015
Dmytro Klets PhD, Igor V. Gritsuk
The results of this work allowed to identify a number of threats to the cybersecurity of automated security-critical automotive systems, which reduces the efficiency of operation, road safety and system safety. Wired or wireless access to the information networks of the modern vehicles allows you to gain control over its power unit, chassis, security system components and comfort systems. According to the criteria for evaluating on-board electronics, the presence of poorly-protected communication channels, the danger of external blocking of vital systems, 75% of the researching modern vehicles do not meet the minimum requirements for cybersecurity. The revealed vulnerabilities of the security-critical automotive systems lead to the need to develop methods for mechanical and electronic protection of the modern vehicle. The law of normal distribution of average points of expert evaluation of cybersecurity of the modern vehicle is defined.
2018-04-03
Technical Paper
2018-01-1376
Aishi Sahu, Mithilesh Kumar Sahu, Sanjay R
Aviation is one of the fastest-growing sources of harmful gaseous emissions to the atmosphere. These emissions give rise to important environmental concerns regarding their global impact and their effect on local air quality at ground level. Aircraft engines account for 2% of all human induced carbon emissions and 12% from transportation sources. Exergoenvironmental analysis of a gas turbine cycle is the combined study of component-wise exergy analysis and the impact of emissions on the environment. The current fossil fuel scenario and the abrupt environmental changes on the earth compels mankind to think about how to increase thermal efficiency of an engine with least possible emission. Aircraft engines based on modified gas turbine cycle are gaining popularity due to their reduced specific fuel consumption, better thermodynamic performance and reduced emissions.
2018-04-03
Technical Paper
2018-01-1324
Xuguang Wang, Georges Beurier
An automotive seat or an airplane passenger seat is used by thousands or millions of people. The seat should be designed to accommodate the maximum number of a target population by taking into account the variability of body size in the population and also the environment’s constraints. Thanks to a fully adjustable experimental seat recently built at IFSTTAR, data of the optimal seat profile parameters and compressed seat pan surface were collected in function of seat pan and backrest angle from a sample of 36 differently sized participants. Parametric models were obtained to predict optimal seat profile parameters in function of a sitter’s anthropometric characteristics, seat pan angle and seat back angle. Using a population simulation approach, a sample of 500 males and 500 females were generated randomly based on the distribution of relevant anthropometric dimensions.
2018-04-03
Technical Paper
2018-01-0150
Max Sardou
SARDOU SAS has developed highly stressed composites parts for 36 years. SARDOU SAS and QUALITY INDUSTRIAL PRODUCT jointly invented and patented composite “C” springs in 1993. We have designed and tested ultra-performance “C” springs, giving an incredible energy density of 1350 joules per kilogram (compared to 300 for steel springs). This energy density means a potential 78% weight savings! But in the last century, weight savings was not a must and platform personnel were reluctant to use anything else than coil springs. So in 2002, in order to comply with the wishes of platform personnel, we have invented and developed composite coils springs. Composite coils springs are the best choice for McPherson suspensions. We have identified that the weak point, in composite coils springs, is its epoxy matrix. During heavy loading, the matrix undergoes micro cracking. Then, during repeated loadings, micro cracks propagate and merge, transforming the matrix into a fine powder.
2018-04-03
Technical Paper
2018-01-0308
Chengguan Wang, Diming Lou, Piqiang Tan, Zhiyuan Hu, Sheng Liu, Zhenhuan Yang
In this study, the effect of altitude on free diesel spray morphology, macroscopic spray characteristics and air-fuel mixing process was investigated. The spray visualization experiment using high-speed photography was performed in a constant volume chamber which reproduced the injection diesel-like thermodynamic conditions of a heavy-duty diesel engine operating at altitudes of 0m, 1000m, 2000m, 3000m and 4500m. The results showed that the spray morphology became narrower and longer at higher altitude, and small vortex-like structures were observed on the downstream spray periphery. Spray penetration increased and its angle decreased with increasing altitude. At altitudes of 0m, 1000m, 2000m, 3000m and 4500m, the spray penetration at 1.45ms after start of injection (ASOI) was 79.54mm, 80.51mm, 81.49mm, 83.29mm and 88.92mm respectively, and the spray angle was 10.9°, 10.8°, 10.7°, 10.4°and 9.8° respectively.
2018-04-03
Technical Paper
2018-01-0666
Muapper Japper Alhadri, Siamak Farhad, Mohammed Abdul Haq
Abstract: Lithium-ion battery is one of the candidates for energy storage for hybrid aircraft. The study herein is intended to investigate the performance and longevity of hybrid aircraft Li-ion battery packs. A physical empirical model along with testing were presented to address the behavior of Li-ion batteries during discharge cycles and storage. The model includes three sub-models to study all effects around the batteries, electrical, thermal, and wear models. This study was linked to the cabin, thermal effects, and environmental conditions. Results were integrated with different equations to obtain required variables. Then, these results were validated using testing of cells under needed conditions to have results compared to aircraft packs. The testing is conducted the cell life during cycling and storage under time, number of cycles and associated with other factors such as temperature, voltage, capacity and C-rate.
2018-04-03
Technical Paper
2018-01-0738
Stuart Allen Gambill, Jerry Dahlberg, Tucker Bisel, Navid Goudarzi, Nithin Narayan, Peter Tkacik
A small scale rolling road wind tunnel was developed and used to experimentally characterize the influence a rotating tire exerts on a free stream flow field. The 150mm x 500mm rolling road is used in a 0.3m2 Eiffel wind tunnel and is comprised of a removable frame that is designed to locate, constrain, and dampen vibration of the road within the wind tunnel. Furthermore, the design included optical access to the volume around the tire to utilize Particle Image Velocimetry (PIV) flow measurements to characterize the flow. The rolling road is controlled with a 3-phase frequency drive and belt control system that matches road speed to the free stream air speed within the tunnel and can operate at speeds up to 120 kph. PIV was used to measure the flow structures around a 1/10th scale (soft rubber) tire. The flow was seeded with an olive oil particle generator and illuminated with a dual power 532 nm Nd:YAG laser.
2018-04-03
Technical Paper
2018-01-0743
Sam Jeyasingham, Kumar Srinivasan
A detailed Design of Experiments (DOE) study is presented to understand the aerodynamic effects of exterior design features and shape parameters of a pick-up truck using Computational Fluid Dynamics (CFD). The goals of the study are to characterize several key design parameters and the interactions between them as related to overall drag of the vehicle. Using this data, the exterior shape is optimized to minimize drag within specified design constraints. An adaptive sampling methodology is also presented that progressively reduces errors in the design response surfaces generated. This combined with a Latin Hypercube based initial design space characterization yields computational efficiency. A trend-predictive meta-model is presented that can be used for early design development. Results from the meta-model are also correlated with experimental data from the wind tunnel.
2018-04-03
Technical Paper
2018-01-0740
Levon Larson, Sudesh Woodiga
The airflow that enters the front grille of a ground vehicle for the purpose of component cooling has a significant effect on aerodynamic drag. This drag component is commonly referred to as cooling drag, which denotes the difference in drag measured between open grille and closed grille conditions. When the front grille is closed, the airflow that would have entered the front grille is redirected around the body; this airflow is commonly referred to as cooling interference airflow. Consequently, cooling interference airflow can lead to differences in vehicle component drag, known as cooling interference drag. Cooling drag generally contributes up to 10% of total vehicle drag and is difficult to predict, due to influences from many direct (engine bay airflow path) and indirect (cooling interference airflow path) factors. Active grille shutters (AGS) are a commonly used mechanism to influence the engine bay airflow drag contribution of cooling drag.
2018-04-03
Technical Paper
2018-01-0745
Yingchao Zhang, Guanmao Du, Junshuai Wang, Bing Fan, Zhe Zhang
In order to explore the method for reducing aerodynamic noise caused by the cavity structure, the typical cavity model M219 scale model was chosen as the basic model. The maximum noise of the basic model and flow inside the cavity can be obtained through the numerical simulation. Inspired by the bionic design, selecting the bionic non-smooth structure by the following two ways: one is selecting the known bionic non-smooth structure from the reference literature which has the good effect on the aerodynamic flow field of the bionic non-smooth structure, such as the bionic v-shaped non-smooth structure and the bionics hemispherical structure; The second is using the method of engineering bionics to select the structure that can realize the improvement of the cavity flow field, which is according to the analysis for the cavity inside flow and cavity aerodynamic noise principle, such as triangle structure and arc structure.
2018-04-03
Technical Paper
2018-01-0725
Renan Francisco Soares, Andrew Knowles, Sergio Goñalons Olives, Kevin Garry, Jennifer Holt
A modern benchmark for passenger cars – DrivAer model – has provided significant contributions to aerodynamics-related topics in automotive engineering, where three categories of passenger cars have been successfully represented. However, a reference model for high-performance car configurations has not been considered appropriately. Technical knowledge in motorsport is also restricted due to competitiveness in performance, reputation and commercial gains. The consequence is a shortage of open-access material to be used as technical references for either motorsport community or academic research purposes. In this paper, a parametric assessment of race car aerodynamic devices are presented into four groups of studies. These are: (i) forebody strakes, (ii) front bumper splitter, (iii) rear-end spoiler, and (iv) underbody diffuser.
2018-04-03
Technical Paper
2018-01-0715
Yusuke Iinuma, Keiichi Taniguchi, Munehiko Oshima
An electric vehicle (EV) has less powertrain energy loss than an internal combustion engine vehicle (ICEV) so its aero drag share of the total energy loss is relatively larger. This means that EV aerodynamic performance has a larger impact on the all-electric range (AER). Therefore, the aim set for the aerodynamics development for a new EV hatchback was to contribute to improving AER for the customer’s benefit. To achieve lower aero drag than the previous model’s good aero performance, an ideal airflow wake structure was initially defined for the new EV hatchback that has a flat underbody with no exhaust system. Several important parameters were specified and proper numerical values for the ideal airflow were defined for them. As a result, the new EV hatchback achieves a 4% reduction in drag coefficient (CD) from the previous model.
2018-04-03
Technical Paper
2018-01-0843
Hirokazu Maekawa
There are air pollution and global warming due to exhaust gas as a problem in the automotive industry. Automotive manufacturer are working on cleaning and reduction of exhaust gas, and improvement of fuel efficiency, because these regulations of exhaust gas in each country are being more severe. In the background of improvement to fuel efficiency and energy loss reduction of power transfer, the requirement for low friction, weight reduction and space saving is increasing to these reciprocating rubber seals such as automatic transmissions. In this study, to satisfy the requirement, the friction characteristic by changing rubber materials and the shape of rubber seal is investigated and studied in consideration of the temperature dependence to the friction of rubber seal. Finally, the rubber seal which provide low friction and space saving is developed.
2018-04-03
Technical Paper
2018-01-1044
Quan LI, Yong HAN, Koji Mizuno
INTRODUCTION: Accidents data have shown that the pedestrian injury due to contact with the ground is serious and may even be worse than the primary contact with vehicles. However, the landing mechanism of pedestrian too complicated to be restored via accident investigation only. Nowadays, pedestrian kinematics during/after collisions can be observed according to the accidents videos. This study was aimed to investigate the pedestrian landing mechanism and analyze the influencing factors based on accident video records. METHODS: This work collected 112 video cases (involved 114 pedestrians) of pedestrian. The pedestrians during / after collision parameters (e.g., accident scenarios, impact velocity, kinematics and trajectory during vehicle impact, and fall kinematics) were analyzed with video information RESULTS: According to the pedestrian accident video records, four types of landing mechanism have been classified based on pedestrian kinematics.
2018-04-03
Technical Paper
2018-01-1240
John S. Medcalf, Brian G. Thomas, Salim V. Brahimi
This work establishes the relationship between core hardness, case hardness, and case depth on susceptibility to hydrogen embrittlement of case hardened steel fasteners. Such fasteners have a high surface hardness in order to create their own threads in a mating hole, and are commonly used to attach bracketry and sheet metal in automotive applications. While case hardened fasteners have been studied previously, there are currently no processing guidelines supported by quantitative data for fastener standards. Through sustained load embrittlement testing techniques, the susceptibility of case hardened steel tapping screws to internal and environmental hydrogen embrittlement is examined. Further characterization of the fastener samples through microhardness testing, microstructure review, and fracture surface examination allows the investigation of susceptibility thresholds. It is shown that core hardness is the primary consideration for susceptibility.
2018-04-03
Technical Paper
2018-01-1027
Daniel Jung, Qadeer Ahmed, Xieyuan Zhang, Giorgio Rizzoni
Hybrid electric vehicles (HEV) are essential for reducing fuel consumption and emissions. In many cases, the same type of electrified powertrains is used for many different tasks and applications. However, when analyzing different segments of the transportation industry, for example, public transportation or different sizes of delivery trucks and how the HEV are used, it is clear that one powertrain is not optimal in all situations. Choosing a hybrid powertrain architecture and proper component sizes is an important task to find the optimal trade-off between fuel economy, drivability, and vehicle cost. However, exploring and evaluating all possible architectures and component sizes is a time-consuming task, both because evaluating the performance of each architecture is computationally costly and because the design search space grows exponentially with the number of components to be optimized.
2018-04-03
Technical Paper
2018-01-0729
Yingchao Zhang, Chao Yang, Qiliang Wang, Dapeng Zhan, Zhe Zhang
F1 racing car is often running in a high-speed, the vehicle body pitch angle often changes because of the rough road or other reasons, resulting in changes of body aerodynamic characteristics will directly affect the car's power and handling stability. It can even make cars and drivers dangerous. This paper takes F1 formula racing car as the object model, the influence of the change of body pitch angle on aerodynamic drag force and aerodynamic lift force of F1 equation racing car was investigated. CFD code--PowerFlow based LBM is used to simulate the aerodynamic characteristics of a car body with different wind speeds and different pitching angles.
2017-12-08
Paper
SN-0003
Small tactical UAVs (SUAVs) have made their mark in military operations with their ability to gather and provide localized, real-time information. Typical uses include perimeter surveillance of remote military compounds, over-the-horizon surveillance, and remote monitoring of critical logistics routes. However, their potential to take on increased and increasingly complex missions is hampered by their limited endurance. This work explores research done under the auspices of the European Commission’s Fuel Cell and Hydrogen Joint Undertaking on a fuel cell and battery hybrid energy storage system that could increase the total amount of onboard energy storage, while continuing to deliver the peak power needs of the SUAV.
2017-11-13
Tech Insights
TI-0002
While all-electric aircraft remain at the bleeding edge of the aviation industry, incorporating technologies like proton exchange membrane fuel cells into existing aircraft can result in considerable auxiliary capability with low environmental impact. However, proper consideration must be given to supporting systems to achieve a reliable balance of plant-especially when those systems interface with existing aircraft architectures. The scope of the BoP is to manage and condition the reactant flows to and from the fuel-cell module and to provide power to system components.
2017-11-07
Technical Paper
2017-36-0217
Roberta de Cássia Ferreira Porto, Marcelo Lopes de Oliveira e Souza
Abstract Systems such as satellites, airplanes, cars and air traffic controls are becoming more complex and/or highly integrated. These systems integrate several technologies inside themselves, and must be able to work in very demanding environments, sometimes with few or none maintenance services due to their severe conditions of work. To survive such severe work conditions, the systems must present high levels of reliability, which are achieved through different approaches, processes, etc. These unfold in many: levels of aggregation (systems, subsystems, equipments, components, etc.), phases of their lifecycles (conception, design, manufacturing, assembly, integration, tests, operation, etc.), environments (land, sea, air, space, etc.), types of components/applications/experiences/technological communities (nuclear, aerospace, military, automotive, medical, commercial, etc.), leaded by the widespread use of semiconductors.
2017-11-07
Technical Paper
2017-36-0150
Marco Gabaldo, Otávio Rodrigues Barros, Jose Eduardo Mautone Barros
Abstract This study analyzes the design of a two-stage reusable satellite launch vehicle. This launcher was designed to orbit payloads of up to 500 kg to low orbits (LEO). Two RISCRAM™ jet engines (Rocket Ignited Supersonic Combustion Ramjet) power the first stage that is fully reusable. They aspirate atmospheric air and allows speeds of up to Mach 6, below 30 km, and Mach 15 above 40 km of altitude. The second stage is powered by a solid rocket motor that carries the payload at the orbital speed of Mach 24. In this work are presented details of the concept of the vehicle and an economic feasibility analysis of system operation. Launch cost estimative are made and compared to the values of the current satellite launchers that are not reusable. The conclusion of the article is that the proposed system would be able to reduce by an order of magnitude the cost of placing the kilogram of payload in low orbit.
2017-11-07
Technical Paper
2017-36-0142
Fábio Coelho Barbosa
Abstract The aviation industry currently holds a share of 2% global greenhouse gas (GHG) emissions. Although relatively small, estimated demand increase indicates an up to 350% emission rise in 2050, in the so called “no action scenario”. These emissions are injected into the upper atmosphere, with a potentialized stronger greenhouse effect than at ground level. In this context, ambitious emission reduction targets have been proposed into a global commitment, focused into a long term carbon emission reduction strategy, which would lead to net GHG emissions to peak in 2020, and then halves by 2050, based on 2005 levels, while accommodating increased air transport demand. To achieve this challenging goal, a multifaceted approach is required, ranging from technology oriented actions, like revolutionary aerodynamically driven design, new composite lightweight material and engine technology improvement, as well as improved ground and flight operational practices.
2017-11-07
Technical Paper
2017-36-0373
Ana Paula de Sá Santos Rabello, Marcelo Lopes de Oliveira e Souza
Abstract Complex and/or highly integrated systems require the evaluation of Dependability (Reliability, Maintainability, Availability, etc.) throughout their life cycle. The designs of these systems have three main sets of activities: managerial, technical and quality. The recent literature suggests that: 1) the growth of the committed project cost is much greater than the cost spent in the initial stages; and also, the cost to eliminate the defects is smaller in the initial stages of project; and 2) the functions, responsibilities, and authorities of Project Management and Systems Engineering are strongly coupled. Thus, based on the recent literature and the INPE´s (National Institute for Space Research) experience, this paper will show a discussion on the interaction between Project Management and Systems Engineering to improve the Dependability of space and automotive projects.
2017-10-31
Paper
WP-0004
The aerospace industry is facing new challenges to meet burgeoning customer demand. An unprecedented number of orders for commercial aircraft is forcing aerospace manufacturing to make gains in efficiency throughout aircraft production and operation. However, current manufacturing systems are using technologies and production methods unsuited to a future dynamic market. To ensure its profitability, the aerospace industry must seize the opportunity to innovate and readdress approaches to manufacturing. This whitepaper looks at four advanced manufacturing (AM) solutions designed to improve assembly process efficiency, automation, and accuracy.
2017-10-31
White Paper
WP-0003
Actuators are the key to sophisticated machines that can perform complex tasks previously done by humans.
2017-10-25
White Paper
WP-0002
The environmental impact of hydrocarbon-burning aircraft, both from the perspective of gas emissions and that of noise, is one of the main motivations for the move to electric propulsion. The added benefit from this shift to electric propulsion is that it has resulted in lowering the costs of electrical components such as motors, power electronic (PE) circuits, and batteries that are essential to this technology. This white paper seeks to explore the history, architecture, electrical components, and future trends of electric flight technology.
2017-10-08
Journal Article
2017-01-2293
Jim Barker, Jacqueline Reid, Sarah Angel Smith, Colin Snape, David Scurr, Graham Langley, Krina Patel, Anastarsia Carter, Cris Lapthorn, Frank Pullen
Abstract Studies of diesel system deposits continue to be the subject of interest and publications worldwide. The introduction of high pressure common rail systems resulting in high fuel temperatures in the system with the concomitant use of fuels of varying solubilizing ability (e.g. ULSD and FAME blends) have seen deposits formed at the tip of the injector and on various internal injector components. Though deposit control additives (DCAs) have been successfully deployed to mitigate the deposit formation, work is still required to understand the nature and composition of these deposits. The study of both tip and internal diesel injector deposits (IDID) has seen the development of a number of bench techniques in an attempt to mimic field injector deposits in the laboratory. One of the most used of these is the Jet Fuel Thermal Oxidation Tester or JFTOT (ASTM D3241).
2017-10-08
Technical Paper
2017-01-2215
Mingming Ma
Abstract A lubricating system modeling method based on flight test data is proposed in this paper. ANN model based on a large number of flight test data is trained and validated, and models of 6 lubricating system parameters in all engine operation settings and whole flight envelope are established. Model results are in good agreement with flight test results, which shows feasibility and effectiveness of the presented modeling method. The model results are packaged in dynamic link library, and the coordination between calculating model and GDAS is accomplished. Comparison of model and flight test results in real-time monitoring of flight test comes true, thus on-line trend monitoring of oil parameters is implemented and applied. Additionally, input parameters are gradually decreased as new input parameter group of ANN structure. Oil parameter model is trained and validated again with the new group of parameters, until leading to unacceptable bias between model and flight test results.
2017-10-08
Technical Paper
2017-01-2408
Lei Zhou, Hongxing Zhang, Zhenfeng Zhao, Fujun Zhang
Abstract The Opposed Piston Two-Stroke (OPTS) engine has many advantages on power density, fuel tolerance, fuel flexibility and package space. A type of self-balanced opposed-piston folded-crank train two-stroke engine for Unmanned Aerial Vehicle (UAV) was studied in this paper. AVL BOOST was used for the thermodynamic simulation. It was a quasi-steady, filling-and-emptying flow analysis -- no intake or exhaust dynamics were simulated. The results were validated against experimental data. The effects of high altitude environment on engine performance have been investigated. Moreover, the matching between the engine and turbocharger was designed and optimized for different altitude levels. The results indicated that, while the altitude is above 6000m, a multi-stage turbocharged engine system need to be considered and optimized for the UAV.
Viewing 1 to 30 of 19859