Browse Topic: Vehicle roofs
Traditional silicon-based solar cells are completely opaque, which works for solar farms and roofs but would defeat the purpose of windows. However, organic solar cells, in which the light absorber is a kind of plastic, can be transparent.
The current Range Rover is the fifth generation of this luxury SUV. With a drag coefficient of 0.30 at launch, it was the most aerodynamically efficient luxury SUV in the world. This aerodynamic efficiency was achieved by applying the latest science. Rear wake control was realised with a large roof spoiler, rear pillar and bodyside shaping, along with an under-floor designed to reduce losses over a wide range of vehicle configurations. This enabled manipulation of the wake structure to reduce drag spread, optimising emissions measured under the WLTP regulations. Along with its low drag coefficient, in an industry first, it was developed explicitly to achieve reduced rear surface contamination with reductions achieved of 70% on the rear screen and 60% over the tailgate when compared against the outgoing product. This supports both perceptions of luxury along with sensor system performance, demonstrating that vehicles can be developed concurrently for low drag and reduced rear soiling. This paper describes the development journey of the car, from initial phases extensively exploiting simulation through to testing pre-production prototype vehicles in both FKFS Aeroacoustic and Thermal Wind Tunnels.
In recent years, engineers at ETH Zurich have developed the technology to produce liquid fuels from sunlight and air. In 2019, they demonstrated the entire thermochemical process chain under real conditions for the first time, in the middle of Zurich, on the roof of ETH Machine Laboratory. These synthetic solar fuels are carbon neutral because they release only as much CO2 during their combustion as was drawn from the air for their production. Two ETH spin-offs, Climeworks and Synhelion, are further developing and commercializing the technologies.
In this study, an optimized structure for opening the headlining considering the deployment of the face-to-face roof airbag was studied. It was confirmed that the deployment performance differs depending on the skin of the headlining, and a standardized structure with mass production was proposed. Non-woven fabric and Tricot skin, which are economical and high-end specifications, satisfy the performance of PVC fusion application specifications after cutting 80% of the skin. The structure that satisfies the entire body including the knit specifications is a type that separates the roof airbag area piece, the corresponding soft piece is separated, and the deployment performance is satisfied with safety. Therefore, the structure is proposed as a standardized structure. This structure is expected to be applicable to roof DAB (Driver Airbag), PAB (Passenger Airbag), and Sunroof Airbag, which will be necessary technologies to secure indoor space. Regardless of which area the airbag will be applied to, and which area the headlining skin specifications will be selected by the customer, it can be applied only if the mounting bracket conditions are satisfied. A patent will be applied for the structure to secure intellectual property rights.
This document details one of the connections of the SAE J3105 document. The connections are referenced in the scope of the main document SAE J3105. SAE J3105/1 details the infrastructure-mounted pantograph, or cross-rail connection. All the common requirements are defined in the main document; the current document provides the details of the connection. This document covers the connection interface relevant requirements for an electric vehicle power transfer system using a conductive automated connection device (ACD) based on a cross-rail design. To allow interoperability for on-road vehicles (in particular, buses and coaches), one configuration is described in this document. Other configurations may be used for non-standard applications (for example, mining trucks or port vehicles).
This SAE Recommended Practice establishes a uniform test procedures for on highway trucks equipped with an air-conditioning system used to condition the air in the cabin and sleeper compartment of the vehicle. This specification will apply to heavy trucks with and without sleeper compartments.
Solar or photovoltaic (PV) cells fixed to roofs convert sunlight into electricity. Bringing that technology indoors could further boost the energy efficiency of buildings and energize swaths of wireless smart technologies such as smoke alarms, cameras, and temperature sensors.
Recreational vehicles have a lot of potential consumers in China, especially the type C recreational vehicle is popular among consumers due to its advantages, prompting an increase in the production and sales volumes. The type C vehicle usually has a higher air drag than the common commercial vehicles due to its unique appearance. It can be reduced by optimizing the structural parameters, thus the energy consumed by the vehicle can be decreased. The external flow field of a recreational vehicle is analyzed by establishing its computational fluid dynamic (CFD) model. The characteristic of the RV’s external flow field is identified based on the simulation result. The approximation models of the vehicle roof parameters and air drag and vehicle volume are established by the response surface method (RSM). The vehicle roof parameters are optimized by multi-objective particle swarm optimization (MO-PSO). According to the comparison, the air drag is reduced by 2.89% and the vehicle volume is increased by 0.36%. For the RV, the proper geometry parameters can increase the inner space of the vehicle while reducing the air drag.
The woofer in a car should be large to cover the low frequencies, so it is heavy and needs an ample space to be installed in a passenger car. The geometry of the woofer should conform to the limited available space and layout in general. In many cases, the passengers feel that the low-frequency contents are not satisfactory although the speaker specification covers the low frequencies. In this work, a thin panel is installed between the roof liner and the roof panel, and it is used as the woofer. The vibration field is controlled by many small actuators to create the speaker and baffle zones to avoid the sound distortion due to the modal interaction. The generation of speaker and baffle zones follows the inverse vibro-acoustic rendering technique. In the actual implementation, a thin acrylic plate of 0.53x0.2 m2 is used as the radiator panel, and the control actuator array is composed of 16 moving-coil actuators. The shape of the desired speaker zone is an ellipse, and the required amplitude of this piston source is pre-calculated to satisfy the desired sound radiation at the ear position. The gain of the actuator array to properly generate the desired vibration field is obtained by solving an inverse problem constructed by the transfer mobility between each actuator and field point on the plate. For the recruitment of the low-frequency deficiency of human auditory characteristics, the desired sound spectrum is set to follow the equal-loudness contour of 40 phons. It is confirmed that the woofer in a car can be replaced by the developed panel speaker.
The sensor arrays that currently reside on the roofs of development mules will be hidden from view on future production vehicles. But how to conceal them without affecting their safety-critical performance? This design and engineering challenge, along with the growing trend toward larger, multifunction interior and exterior displays, is driving new polycarbonate solutions at Covestro, which was spun off from Bayer Materials Science in 2015. For insights into this new family of materials, editor Lindsay Brooke spoke with Paul Platte, a mechanical engineer by training who now is part of Covestro's marketing team.
Composites technology for the automotive market continues to advance rapidly. Increasing knowledge of composite design, simulation tools, new materials and process equipment are all contributing to make composites better performing and more affordable for mass-produced vehicles. In particular, the high pressure resin transfer molding (HP-RTM) and related liquid compression molding (LCM) processes are enabling manufacturers to produce complex composite parts at shorter and shorter cycle times. This paper describes the development of an epoxy carbon fiber roof frame targeted for future vehicle production. Several composite processes were considered for the roof frame. The case illustrates that when the (product) design, material and process are considered together, a high-performing, cost-efficient part can be produced. The resulting carbon fiber roof frame met all OEM performance requirements and economic targets while weighing 44% less than the original design in magnesium and 32% less on the overall assembly. The part was the first HP-RTM part successfully demonstrated in North America and stands as a model for future lightweighting developments. Of equal significance, the development process for the part involved a unique collaboration of companies throughout the automotive composites value chain. Each company contributed their particular expertise to the project including resin technology, reinforcement solutions, engineering analysis, process simulation, tool construction, preforms and molding. The collaboration enhanced the speed and technical success of the overall development.
Sunroof is placed in certain high-end vehicles to give user a better driving experience. All automakers are searching alternatives to reduce weight and cost in the vehicle, in which sunroofs are also impacted. Some alternatives are already applied, as a honeycomb paper used in some sunshades that presents benefits, as less weight and with a good cost reduction. Although, due the reduced weight for this part produced in this material, it shows more susceptibility to reproduce the vibration that vehicle propagates in movement, especially in bad condition roads. The sunroof assembly is dependent of the roof reinforcement and roof skin, but in this special case, the validation could be done in the components itself because the interaction of the sunshades is directly dependent of the other sunroof parts, as rails and front frame. These buzz noise in lights sunshades is perceptible when it is almost or totally close, since lighter material vibrates freely without rail anchorage, then clashing against the front frame surface. Considering the package, the key point is to design the sunshade to have always an interference against the front frame, ensuring the effort to open and close are not excessive. In addition, the material that covers the sunshade must not have degraded appearance after user normal lifetime. If cost is not a project roadblock, the component could be designed using different material and shape. To summarize, to complete design validation, specific test must be performed to evaluate wear and effort. To summarize, vehicle driving tests must be performed to guarantee the complete functionality for this part, with no generation of disadvantage for users.
Reinforcing the Corvette's long association with astronauts, Chevrolet unveiled the convertible version of its all-new, mid-engine-layout 2020 Corvette Stingray in Cape Canaveral in early October. Executive chief engineer Tadge Juechter, underscoring the car's no-compromises performance and comparatively affordable price, called it a “no-lose proposition” for enthusiasts considering the new Corvette but also desiring a more open-top experience. When it goes into production in the first quarter of 2020, the Corvette Stingray convertible will start at $67,495 - $7,500 more than the 2020 Stingray coupe, which was widely celebrated for its aggressive $59,995 base price. Although called a convertible, there is no fabric to be seen: the 2020 Corvette Stingray convertible uses a folding-hardtop design in which the center roof section folds in two pieces and stores above the rear-mounted engine. From some angles the new Corvette convertible will be difficult to distinguish from the standard Stingray coupe, even with the roof open. The giveaway is the glass rear hatch on the coupe that exposes the engine to view. The convertible does without this glass cover, but uses an upright section of glass behind the driver flanked by pronounced buttresses. The bodywork covering the engine is solid, with a rear-opening section that more closely resembles a conventional trunk.
Tractors in the field are exposed to adverse operating conditions and are surrounded by dust and dirt. The tiny, thin and sharp broken straw and husks surround the system in reaper operation. The tractors which are equipped with air conditioning system tend to show detrimental effects in cooling performance. The compressor trips frequently by excess pressure developed in the system due to condenser clogging and hence cooling performance is reduced considerably. The air conditioning performance reduces due to the clogged condenser located on the top roof compartment of operator’s cabin, which is better design than keeping in front of radiator where clogging happens every hour and customer need to stop the tractor to clean it with specific blower. The present system is designed keeping condenser at the top of the roof where heavy particles won’t reach easily, So, condenser choking/clogging is observed every 2 hours, this makes the operator to perform repetitive cleaning operations with specific equipment and is a time-consuming process. The present system utilizes the condenser fan operating logic to eliminate this issue and enhance overall system performance by rotating in opposite direction.
Noise, vibration, and harshness (NVH) attribute is needed to be included in the vehicle structure design since improving the NVH characteristics enhances the ride quality experienced by the occupants. In this regard, an efficient method was proposed to investigate the structural dynamic response of an automotive body considering low-frequency NVH performances. Moreover, the improvement of an automotive structure under the constraint of NVH behavior was investigated by using the design of experiments (DOEs) method. The DOEs methodology was for screening of the design space and generating approximation models. Here, the thicknesses of panels consisting of a body-in-white (BIW) of an automotive were employed as design variables for optimization, whose objective was to increase the first torsional and bending natural frequencies. Central composite design (CCD) for DOEs sampling and response surface methodology (RSM) were employed to optimize the dynamic stiffness. Moreover, the effects of the selected variables as well as their binary interactions were modeled and the optimum conditions for rigidity improvement were obtained via the RSM. Furthermore, the validity of the proposed optimization scheme was verified through CAE analysis. The results indicated that the first torsion and bending natural frequency were improved compared to the baseline design. Additionally, precise surrogate models in polynomial terms for the first bending and torsion natural frequencies were obtained.
ABSTRACT In this paper, we present Pegasus Transforming UAV/UGV Hybrid Vehicle, a unique, transformable UAS/UGV that is particularly well-suited for missions. The combination of flight and ground modalities allows Pegasus to fly to location, automatically transform into a ground vehicle, reposition, and quietly approach a target; or, Pegasus can land and “perch” for long durations, allowing for the maintenance of the custody trail and long ISR missions or emplace sensors particular for a specific mission. The sequential use of aerial and ground capabilities in this platform provides the reach usually lacking in these missions. The Pegasus platform was developed with DTRA/ARDEC funding in support of specialized missions where these functionalities are needed. Robotic Research, LLC has developed the system from the ground up, including: mechanical, electrical, and software designs (without using foreign-made parts). The current system is shown in Figure 2. The system already has obstacle avoidance payloads, and has demonstrated capabilities in GPS-denied environments and SubT, while mapping and traversing line-of-sight and NLOS areas. Figure 2 Pegasus quietly drives to a location, flies to a roof, and repositions on top of the roof to point to the OP.
Sports Utility Vehicles (SUVs) typically have a blunt rear end shape (for design and practicality), however this is not beneficial for aerodynamic drag. Drag can be reduced by a number of passive and active methods such as tapering and blowing into the base. In an effort to combine these effects and to reduce the drag of a visually square geometry slots have been introduced in the upper side and roof trailing edges of a squareback geometry, to take air from the freestream and passively injects it into the base of the vehicle to effectively create a tapered body. This investigation has been conducted in the Loughborough University’s Large Wind Tunnel with the ¼ scale generic SUV model. The basic aerodynamic effect of a range of body tapers and straight slots have been assessed for 0° yaw. This includes force and pressure measurements for most configurations. The slots generate useful, but small, drag reductions with the best configurations giving reductions in drag coefficient (Cd) of approximately 0.01, whereas the best taper configurations reduce Cd by close to 0.035. The slots also have a tendency to modify the lift.
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