Browse Topic: Fairings
The commercial vehicle development process needs to consider the vehicle aerodynamics not only in ideal flow conditions, but also in the turbulent real world environment. The turbulent real world environment includes not only atmospheric turbulence, but also the vehicle to vehicle interactions that happen when driving around other vehicles or into and out of the wake of in/on coming vehicles. A vehicle driving into the wake of an oncoming vehicle not only experiences an increase in the total aerodynamic forces, it also experiences unsteady transient loads over the vehicle components such as windshield, mirror, sunvisor, door and side fairing. To properly design specific components, designers need to understand the magnitude of unsteady forces on various vehicle components, otherwise these components may fail which imposes warranty and safety risks. In this paper, we attempt to understand the various forces acting on the primary vehicle during a passing maneuver. The main purpose is to
Conventional high-lift systems allow transport aircraft to safely operate at low speeds for landing and takeoff. These high-lift devices, such as Fowler flaps, are complex, heavy, and have high part counts. Fowler flap mechanisms also protrude externally under the wings, requiring external fairings, which increase cruise drag. Simple-hinged flaps are less complex, and an ideal choice for low-drag cruise efficiency. However, simple-hinged flaps require high flap deflections to achieve lift comparable to Fowler flaps. These flap deflections cause severe adverse pressure gradients, which generate flow separation that is difficult to control. In response to these challenges, NASA developed the High Efficiency Low Power (HELP) active flow control (AFC) system.
Fabrication and assembly of the majority of control surfaces for Boeing’s 777X airplane is completed at the Boeing Defense, Space and Security (BDS) site in St. Louis, Missouri. The former 777 airplane has been revamped to compete with affordability goals and contentious markets requiring cost-effective production technologies with high maturity and reliability. With tens of thousands of fasteners per shipset, the tasks of drilling, countersinking, hole inspection, and temporary fastener installation are automated. Additionally and wherever possible, blueprint fasteners are automatically installed. Initial production is supported by four (4) Electroimpact robotic systems embedded into a pulse-line production system requiring strategic processing and safeguarding solutions to manage several key layout, build and product flow constraints. Commonality amongst the robots was desired to allow each to effectively address any of the commodities which range from small fairings to very large
NASA's Langley Research Center has designed a Multifunctional Boost Protective Cover (MBPC) for a Launch Abort System (LAS). In the event of a crewed launch, the innovation provides a redundant means of saving the crew, and for an unmanned launch, it provides the means for recovering a very expensive, sensitive, and/or dangerous payload. In addition, costs are reduced by minimizing insurance premiums and costly delays to fabricate new, complex satellite systems in the event of a failed launch. NASA is seeking development partners and potential licensees.
Vehicle performance is highly dependent on the design and material used. Fairing of a Human Powered Vehicle (HPV) is responsible for the reduction in the aerodynamic drag force and its material determines the overall weight and the top speed of the vehicle. Selection of material for fairings depends on various physical, mechanical and manufacturing properties along with practical considerations like availability of material. Today, an ever-increasing variety of composite materials and polymers are available, each of them possessing their own characteristics, applications, advantages and limitations. Many automotive composites are used for manufacturing fairings. Materials like Carbon fiber, Glass fiber (E glass, S glass), Aramid fiber (Kevlar 29, Kevlar 49) are some of the viable options that have been used in the past for manufacturing fairing of HPVs. The problem of material selection arises because of conflicting attributes of different alternative materials with respect to the
A roof fairing is a commonly used add-on for trucks or tractor-trailers, where a significant difference in height exists between the cabin and the container. A roof fairing reduces the aerodynamic drag on the vehicle by directing the onward wind flow smoothly onto the container and thus reducing flow separation in front of the container. Since standard containers are available in two different heights and there are cases when vehicles ply without load i.e. without a container, it is necessary to adjust the height of the fairing accordingly to maintain an optimum aerodynamic configuration. While adjustable fairings have been in use in the commercial vehicle industry, these fairings are usually shaped as flat plates, often with open sides for ease of folding. A highly curved and bulbous fairing helps in reducing drag better, especially in presence of side winds, although it makes adjustability difficult. The current paper presents the benefits of installing an adjustable roof fairing on
The OVERFLOW chimera grid Navier Stokes code was used to analyze a wide variety of airplane configurations. The code performed reliably and was found to have comparable accuracy to the structured grid code TLNS3D. It is easier to develop overlapping grid blocks to represent a complex configuration than it is to develop grid blocks that must abut one another. The process is inherently modular. One can add or subtract components like tip-lights, compound winglets, struts, nacelles, tails and fairings at will. The gain in grid simplicity is offset by the complication in specifying block connectivity, however. The overset blocks are typically of better quality, but there is a drawback in that it is not always possible to guarantee flux conservation. The recent development of software for automatic connectivity holds promise for the routine use of OVERFLOW by design engineers.
This SAE Recommended Practice applies to the location, number, color, and functioning of lamps and retro-reflecting devices installed on road vehicles. It provides a common denominator for installation requirements of lighting and light signaling devices based on existing regulatory requirements and industry standards of North America, Europe, and Asia. This document does not replace regulatory requirements in effect at the time of application. It is subject to changes to reflect additional experience, technical advances, and especially changes in government and industry documents used as references. Users of this document are advised to verify current legal requirements, regarding the mandatory installation of additional lighting devices or installation restrictions for devices described herein, directly with the appropriate authorities in the territory where their products are intended to be registered.
This ARP covers the recommended lighting performance and design criteria for: (a) Left Forward Navigation Position Lights (Red) (b) Right Forward Navigation Position Lights (Green) (c) Rear Navigation Position (White) (d) Anti-Collision Lights (Red and/or White Flashing)
WHAT can be done to increase safety, efficiency and comfort in flight of aircraft now in use? In answer, the author describes several devices designed to bring about this result and supplements this with the results of wind-tunnel research. Detailed descriptions of the particular devices mentioned are not included, the object of this paper being to show the great possibilities of their use and the resulting improvement in performance. Among the possible improvements mentioned are variable-lift units, lift-increasing mechanisms with particular reference to a flap developed by the author, an improved rolling control arrangement, locating the tail surfaces out of the propeller slipstream to increase longitudinal stability, reducing the parasite resistance by special circular cowlings for radial engines and wheel fairings and the elimination of lift struts, better utilization of the available engine horsepower by employing a variable-pitch propeller, means for increasing drag when gliding
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