Browse Topic: Wheel wells
This aerospace information report (AIR) provides historical design information for various aircraft landing gear and actuation/control systems that may be useful in the design of future systems for similar applications. It presents the basic characteristics, hardware descriptions, functional schematics, and discussions of the actuation mechanisms, controls, and alternate release systems. The report is divided into two basic sections: 1 Landing gear actuation system history from 1876 to the present. This section provides an overview and the defining examples that demonstrate the evolution of landing gear actuation systems to the present day. 2 This section of the report provides an in depth review of various aircraft. A summary table of aircraft detail contained within this section is provided in paragraph 4.1. The intent is to add new and old aircraft retraction/extension systems to this AIR as the data becomes available. NOTES 1 For some aircraft, the description is incomplete, due to difficulties in obtaining the data.
Laminated steel body panels are used in different applications in vehicles, such as dash panels and wheel wells. A part made out of laminated steel has the potential to provide structure-borne noise reduction and also improve the airborne noise reduction of the part compared to a monolithic part. The use of laminated steel has been more critical when there are deep draws on the part as the deep draws cause localized resonances which degrade the acoustic performance significantly. However, due to lightweighting demands, hybrid laminated panels, commonly known as acoustic patch laminates have become very attractive. This paper discusses the damping and sound transmission loss performances of a dash panel part with monolithic, laminated, and acoustic patch panels. The paper discusses the damping performance below 1000 Hz, including the data analysis process and the effectiveness of the acoustic patch laminates for both structure borne and airborne noise studies including coincidence dip issues. Finally, the paper discusses the potential of the acoustic patch laminates to address lightweighting demands and acoustic values that are driving the vehicle industry today.
This Aerospace Information Report (AIR) describes conditions under which freezing (frozen) brakes can occur and describes operating procedures which have been used to prevent or lessen the severity or probability of brake freezing. This document also identifies design features that some manufacturers implement to minimize the occurrence of freezing brakes. This document is not an Aerospace Recommended Practice (ARP) and therefore does not make recommendations based on a consensus of the industry. However, part of this document’s purpose is to describe the design and operational practices that some are using to minimize the risk of frozen brakes. NOTE: The following information is based upon experience gained across a wide-range of aircraft types and operational profiles, and should NOT take precedence over Aircraft Flight Manual or Flight Operations Procedures.
The Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) awarded a contract to Southwest Research Institute (SwRI) to conduct research and testing in the interest of motorcoach fire safety. The goal of this program was to develop and validate procedures and metrics to evaluate current and future detection, suppression, and exterior fire-hardening technologies that prevent or delay fire penetration into the passenger compartment of a motorcoach - in order to increase passenger evacuation time. The program was initiated with a literature review and characterization of the thermal environment of motorcoach fires and survey of engine compartments, firewalls, and wheel wells of motorcoaches currently in North American service. These characterizations assisted in the development of test methods and identification of the metrics for analysis. Test fixtures were designed and fabricated to simulate a representative engine compartment and wheel well. Fire scenarios were developed for each fixture, the current detection, suppression, and fire-hardening technologies were reviewed and a sample set selected to validate the test procedures developed during this program. Based on the results of testing and feedback from stakeholders, test methods and metrics were developed for evaluating wheel well warning systems, engine compartment detection and suppression systems, and fire-hardening systems. Detailed program conclusions and recommendations for areas of interest for further research and testing are also discussed.
This AIR describes conditions under which freezing brakes can occur and offers suggested design features to minimize occurrence. It also suggests operating procedures which have been shown to prevent or lessen the severity of brake freezing.
Tire cavity noise has long been one of the main road noise issues. Various ideas for devices to reduce tire cavity noise have been patented or discussed in technical reports, but many issues remain for commercialization, and at present only some tires have appeared as products. Therefore, technology was developed for mounting Helmholtz resonators on the wheels, enabling reduction of tire cavity noise without placing restrictions on the tires. The advantage of this technology is that the cost and productivity targets needed for mass production can be satisfied without impairing the tire and wheel functions. The aim of this development was to construct low-cost device technology that is well-suited to mass production and enables reduction of tire cavity noise to an inaudible sound pressure without adversely affecting dynamic product marketability such as strength and durability performance and handling performance. In order to realize that aim, the device configuration employed a structure that assembles separate thin, lightweight plastic resonators in the wheel well. The main structural feature is the fitting and fixing of thin, lightweight plastic Helmholtz resonators in grooves newly cut in the wheels, with the basic concept of the design being to increase the resonator holding force when centrifugal force acts upon it. The cabin noise was verified by driving a vehicle equipped with these tire cavity noise-reducing wheels over a rough road surface. The results confirmed noise reduction effects of approximately −10 dB, and tire cavity noise was also reduced to an inaudible level.
This SAE Recommended Practice covers the design and application of primary on-board wiring distribution system harnesses to road vehicles. This document applies to any wiring system which contains one or more circuits operating between 50 V DC or AC RMS and 600 V DC or AC RMS excluding automotive ignition cable.
Three different acoustic finite element models of an automobile passenger compartment are developed and experimentally assessed. The three different models are a traditional model, an improved model, and an optimized model. The traditional model represents the passenger and trunk compartment cavities and the coupling between them through the rear seat cavity. The improved model includes traditional acoustic models of the passenger and trunk compartments, as well as equivalent-acoustic finite element models of the front and rear seats, parcel shelf, door volumes, instrument panel, and trunk wheel well volume. An optimized version of the improved acoustic model is developed by modifying the equivalent-acoustic properties. Modal analysis tests of a vehicle were conducted using loudspeaker excitation to identify the compartment cavity modes and sound pressure response to 500 Hz to assess the accuracy of the acoustic models. The optimized acoustic model is also coupled with a structural finite-element model of the trimmed body to evaluate the effect of body panel flexibility on the interior sound pressure response. The optimized acoustic model is found to exhibit the best correlation in terms of the predicted sound pressure FRF response at the passenger compartment interior locations and at the compartment boundary surfaces.
For its first pickup, Honda turned to the experts by relying on truck-loving engineers at its Ohio R&D center to lead the development project. Now that the 2006 Honda Ridgeline is making its mark in the pickup truck segment, the lead engineers who brought it to market are on to other challenges. Only time will tell whether Gary Flint, Jim Keller, Ken Lantz, and Kevin Thelen are as successful in their new endeavors as they were with the Ridgeline.
SAE 100 Future look: Cell phones, high-end stereos, satellite radios, navigation systems, CD and DVD players. No it's not necessarily the inventory at your local consumer-electronics store. These are just some of the audio-related devices used in cars today, and surely these and others will be staples in the car of tomorrow. As a result, automobiles will have to become significantly quieter, keeping the noise out so passengers inside can enjoy the latest advances in communications and entertainment technologies.
Air Conditioning System - General - Dealing with Design Features
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