2 edition of Landing gear and cavity noise prediction found in the catalog.
Landing gear and cavity noise prediction
Donald B. Bliss
by U.S. National Aeronautics and Space Administration, for sale by the National Technical Information Service in Washington, Springfield, Va
Written in English
|Statement||Donald B. Bliss and Richard E. Hayden ; prepared by Bolt, Beranek, and Newman Inc., Cambridge, Mass. for Langley Research Center.|
|Series||NASA contractor report ; NASA CR-2714, NASA contractor report -- NASA CR-2714.|
|Contributions||Hayden, Richard E., Bolt, Beranek, and Newman, inc., Langley Research Center., United States. National Aeronautics and Space Administration.|
|The Physical Object|
|Pagination||v, 52 p. :|
|Number of Pages||52|
Some aircraft have exhibited a noticeable vibration and aero-acoustic phenomenon inside the nose landing gear cavity. The goal of the present study was to determine whether unsteady CFD using either unsteady RANS or detached eddy simulation (DES) could predict the cavity oscillation that was measured in a Boeing wind tunnel test. Full representation of the landing gear detail and associated structures (e.g. bay cavity, bay doors, belly fuselage etc.) are included and addressed at a realistic scale. The Nose Landing Gear is designed at full scale and the Main Landing Gear at half scale. Implementation of low-noise technologies. 4.
Aircraft landing gears are known to be a major noise source at approach conditions, and the prediction of landing gear noise [Refs ] and its reduction [Refs ] have been active research topics for many years. Due to the intricate geometry of landing gear designs and the complex flow conditions, landing gear noise prediction for. Then, the landing gear model was installed close to the trailing and the leading side of the cavity, respectively. It was observed that installation close to the leading side can help disturb the shear layer so as to suppress the oscillation, while the trailing one can make the landing gear itself produce lower noise.
the prediction. Then, the nose landing gear model was installed close to the leading and the trailing edges of the cavity, respectively. This allows discussing the interaction between the nose landing gear and the cavity in the two retraction systems. At last, conclusions on the acoustic per-formance of the forward/rearward retraction of the nose. Wheels are one of the major noise sources of landing gears. Accurate numerical predictions of wheel noise can provide an insight into the physical mechanism of landing gear noise generation and can aid in the design of noise control devices. The major noise sources of a 33% scaled isolated landing gear wheel are investigated by simulating three different wheel configurations using high-order.
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Landing gear and cavity noise prediction. Washington: U.S. National Aeronautics and Space Administration ; Springfield, Va.: For sale by the National Technical Information Service, (OCoLC) Material Type: Government publication, National government publication: Document Type: Book: All Authors / Contributors.
Prediction of airframe noise radiation from the landing gear and wheel wells of commercial aircraft is examined. Measurements of these components on typical aircraft are presented and potential noise sources identified.
Semiempirical expressions for the sound generation by these sources are developed from available experimental data and theoretical analyses. Landing gear and cavity noise prediction Prediction of airframe noise radiation from the landing gear and wheel wells of commercial aircraft is examined.
Measurements of these components on typical aircraft are presented and potential noise sources identified. Semiempirical expressions for the sound generation by these sources are developed.
The noise generated by a landing gear wheel with hub and rim cavities Journal of Sound and Vibration, Vol. High-Order Numerical Simulations of An Isolated Landing Gear Wheel with A Hub Cavity.
Landing gear and cavity noise prediction. Report, National Aeronautics and Space Administration, USA, July Google Scholar. Dedoussi IC, Hynes TP and Siller H. Investigating landing gear noise using fly-over data: the case of a Boeing Author: Zhifei Guo, Peiqing Liu, Jin Zhang, Hao Guo.
Detached-eddy simulations of the LAGOON landing gear configuration are performed using different unstructured meshes. One mesh is generated based on available experimental and numerical data, and based on this first mesh, a second one is carefully designed to improve the solutions in regions of strong unsteadiness.
The landing gear bay was simplified as a rectangular cavity, and tests were conducted in an aeroacoustics wind tunnel. The cavity oscillation was first analyzed with different incoming speeds. Cavity resonance, depending on the design of the landing gear, can be one of the dominant noise sources related to landing gears in certain frequency ranges.
Wheel bays are susceptible to resonance based on feedback between the internal cavity pressure and the shear layer over the cavity opening as discussed by Bliss and Hayden . RETRACTED: A component-based model for aircraft landing gear noise prediction Journal of Sound and Vibration, Vol.
No. DES Investigation of Devices for Reducing Landing-Gear Cavity Noise. Thus, it is highly recommended to include cavity-noise estimations in the current prediction models, or to simply eliminate such cavities where possible with the use of cavity caps.
 “ Environmental Noise Guidelines for the European Region,” Tech. Rept., World Health Organization, Regional Office for Europe, Copenhagen, High-order CAA simulations were performed to investigate the flow features and far-field acoustics of three different landing gear wheel configurations to isolate the effects of a hub cavity and rim cavities on landing gear wheel noise.
The baseline configuration is the same with the geometry used in the experimental work by Zhang et al. Prediction of airframe noise radiation from the landing gear and wheel wells of commercial aircraft is examined.
Measurements of these components on typical aircraft are presented and potential. The second major challenge of landing gear noise prediction is related to the complexity of the flow to be solved.
Landing gear flow contains a mix of attached boundary layers with fully turbulent detached flow, interactions between different geometrical components and massive flow detachments that are very sensitive to adverse pressure gradients.
Landing gear is the undercarriage of an aircraft or spacecraft and may be used for either takeoff or aircraft it is generally needed for both.
It was also formerly called alighting gear by some manufacturers, such as the Glenn L. Martin aircraft, Stinton makes the terminology distinction undercarriage (British) = landing gear (US).
Acoustic Prediction of the LAGOON Landing Gear: Cavity Noise and Coherent Structures Article (PDF Available) in AIAA Journal 56(11) August with Reads How we measure 'reads'. The first experimental model is a simplified two-wheel landing gear referred from the LAGOON project [10,11].As shown in Fig.
1(a), the model includes one segmented cylindrical strut, one cylinder axle and two wheels, without any part of the fuselage.
The wheel diameter D is mm and each wheel has a ring cavity in the inner wheel region with the outer diameter d out = 81 mm, the. bomb bay, landing gear box, and etc., and a Rossiter’s semi-empirical formula (Rossiter ) has widely been used for data correlations.
An automobile door cavity is also an important auto-mobile airframe noise source. Our special interest lies in prediction and understanding of aeroacoustic tonal noise from the automobile door cavity. Acoustic Prediction of the LAGOON Landing Gear: Cavity Noise and Coherent Structures.
Article. Landing gear noise is one of the dominant noise sources from an aircraft during approach phase. The airframe noise models include the landing gear noise prediction of Guo [45 a simple rectangular cavity is designed as the landing gear bay.
Both the cavity combined with LAGOON and the. Airframe Noise Prediction of a Full Aircraft in Model and Full Scale Using a Lattice Boltzmann Approach The main landing gear, including the wheel cavity, was developed from the original full-scale geometry files containing the finer details of the gear as deployed on the actual aircraft.
The larger structures residing within the wheel well. Landing gear and cavity noise prediction. By R. E. Hayden and D. B. Bliss. Abstract. Prediction of airframe noise radiation from the landing gear and wheel wells of commercial aircraft is examined.
Measurements of these components on typical aircraft are presented and potential noise sources identified.
Semiempirical expressions for the sound.Hybrid RANS-LES Modeling for Cavity Aeroacoustics Predictions $ Landing Gear Aerodynamic Noise Prediction Using Unstructured Grids $ The Simulation of Airframe Noise Applying Euler-Perturbation and Acoustic Analogy Approaches $ This paper is mainly focused on the control strategies explored in the last decade for aircraft airframe noise reduction.
Details of the airframe noise mechanism and the noise numerical predictions can be found in the review by Dobrzynski 11 summarising the airframe noise research achievements worldwide in the last 40 years. We first briefly summarise the noise mechanisms of landing gear .