Written in EnglishRead online
|Statement||Alan J. Bilanin and Joel E. Hirsh.|
|Series||NASA contractor report ; NASA CR-2994, NASA contractor report -- NASA CR-2994.|
|Contributions||Hirsh, Joel E., United States. National Aeronautics and Space Administration. Scientific and Technical Information Office.|
|The Physical Object|
|Pagination||73 p. :|
|Number of Pages||73|
Download Application of second-order turbulent modeling to the prediction of radiated aerodynamic sound
Application of second-order turbulent modeling to the prediction of radiated aerodynamic sound. Washington: National Aeronautics and Space Administration, Scientific and Technical Information Office ; Springfield, Va.: for sale by the National Technical.
The noise radiated from isotropic turbulence at low Mach numbers and high Reynolds numbers, as derived by Proudman (), was the first application of Lighthill's “Theory of Aerodynamic Noise. R.A.D. Akkermans, R. Ewert, M.S.A. Moghadam, J.
Dierke, N. Buchmann, " Overset DNS with Application to Sound Source Prediction, " In Progress in Hybrid. The present study concerns the application of large eddy simulation (LES) and implicit LES (ILES) to engineering flow problems.
Such applications are often very complicated, involving both complex geometries and complex physics, such as turbulence, Cited by: Its downstream predictions are only 74% and 40% of those of the annular loaded and unloaded cascades, respectively.
Likewise, for upstream the figures are 44% and 29%. This amounts to about dB in radiated sound prediction. Sound Scattering in a Swirling Flow: Effect of Hub-Tip Ratio We first examine the cascade three-dimensional by: 8.
Computational approaches are being developed to study a range of problems in aeroacoustics. These aeroacoustic problems may be classified based on the physical processes responsible for the sound radiation, and range from linear problems of radiation, refraction, and scattering in known base flows or by solid bodies, to sound generation by by: Space-time correlation is a staple method for investigating the dynamic coupling of spatial and temporal scales of motion in turbulent flows.
In this article, we review the space-time correlation models in both the Eulerian and Lagrangian frames of reference, which include the random sweeping and local straining models for isotropic and homogeneous turbulence, Taylor's frozen-flow model and Cited by: Firstly, the aerodynamic resistance and lift of the pantograph are computed in this paper, which is compared with the experimental results.
As shown from the result, the above proposed simulation method is very reliable. Secondly, the velocity field and vorticity distribution of the pantograph are computed under the effect of the fluid.
It is presented from the result that the values of the Cited by: 1. 3 Numerical Weather and Climate Prediction is an excellent book for those who want a comprehensive introduction to numerical modeling of the atmosphere and Earth system, whether their interest is in weather forecasting, climate modeling, or many other applica- tions of numerical models.
The book is comprehensive, well written, and contains. According to the statements exposed above, the aim of this work is the development, application and validation Application of second-order turbulent modeling to the prediction of radiated aerodynamic sound book an LES model of the turbulent flow around a typical wind turbine airfoil.
The numerical procedures are presented and described in detail, in order to serve as a guide to another LES modeling works of similar : Irene Solís-Gallego, Katia María Argüelles Díaz, Jesús Manuel Fernández Oro, Sandra Velarde-Suárez.
Siegert, R., Schwarz, V., and Reichenberger, J. (): Numerical simulation of aeroacoustic sound generated by generic bodies placed on a plate: Part II — Prediction of radiated sound pressure.
AIAA Paper Google Scholar. The present investigation discusses the resolution of the turbulent vortical motion behind two bluff bodies. The LES results of the cylinder wake at Reynolds number of 5, showed good comparisons to the published experimental data in terms of the global and local wake characteristics such as the drag and base pressure coefficients, shedding frequencies, near wake structure, and the Reynolds.
An exemplary engine noise reduction system, can be provided, which can include a noise reduction fluid source, and a microjet(s) placed at an axial location downstream from a nozzle exit of an engine and configured to asymmetrically inject a noise reduction fluid from the noise reduction fluid source into a jet flow of the engine.
The engine can be a jet engine. As one of the main aerodynamic noise sources of high-speed trains, the pantograph is a complex structure containing many components, and the flow around it is extremely dynamic, with high-level turbulence.
This study analyzed the near-field unsteady flow around a pantograph using a large-eddy simulation (LES) with high-order finite difference schemes. The influence of turbulence modeling on the broad band noise simulation for complex flow simulation by Greshchner () has provided valuable insights to predict overall sound pressure and power for an application to rod-aerofoil.
In many practical applications involving turbulent flows, noise does not have any distinct tones, and the sound Cited by: 2. Tire–pavement interaction noise (TPIN) is dominant for passenger vehicles above 40 km/h and 70 km/h for trucks.
In order to reduce TPIN, numerous investigations have been conducted to reveal the influencing parameters. In this work, the influencing parameters on TPIN were reviewed and divided into five categories: driver influence parameters, tire related parameters, tread pattern parameters Cited by: 2.
(28), and provided the location is not very close to a sound source. Sound Power Again in the case of the oscillating piston, we will consider the sound power radiated by the piston into the tube.
The sound power radiated by the piston, W, is W = SI (29) FUNDAMENTALS OF ACOUSTICS, NOISE, AND VIBRATION – Immediate hearing damage. The general subject of my research is computation of fluid flow and heat convective transfer using finite volume computations.
I'm working with an in-house finite volume codes (CALC-BVC, CALC-LES), which have been developed within the group.
Juvé, D.,Experimental characterization of jet noise, in Measurement, simulation and control of subsonic and supersonic jet noise, Lecture Seriesvon Kàrmàn Institute for Fluid Dynamics, ISBN, Bailly, C., Bogey, C. & Castelain, T.,Subsonic and supersonic jet mixing noise, in Measurement, simulation and control of subsonic and supersonic jet.
The study of flow-induced noise was stimulated in the early fifties when airliners powered by jet engines entered the commercial market. A fundamental paper which explained the physics of sound generation by turbulence was published by Lighthill in In the same time-frame, pioneering work by Powell (), Ffowcs Williams and Curle provided insights which paved the way for future progress.
This banner text can have markup. web; books; video; audio; software; images; Toggle navigation. Complex Flow Computation of Low Reynolds Number Aerodynamic Characteristics of a Flapping Wing in Free Flight.- Application of Window Embedment Grid Technique.- Improved Component Buildup Method for Fast Prediction of the Aerodynamic Performances of a Vertical Takeoff and Landing Micro Air Vehicle.- Complex Flow Sound radiation from vibrating structures: Measurement of radiated power, elementary radiators, sound radiation from bending waves.
Passive attenuation of structure-borne sound: Damping models, effect of elastic interlayers, blocking masses, changes of material and cross-section. The 36 forms of the acoustic wave equation derived in an earlier review (Campos, L.
C.,“On 36 Forms of the Acoustic Wave Equation in Potential Flows and Inhomogeneous Media,” Appl. Mech. Rev., 60, pp. –) were grouped in four classes, of which the last (Class IV) concerned sheared mean flows; another type of vortical flow is swirling flow, and thus the present review Cited by: The dilating vortex particle methoddeveloped in previous workis used for the high-fidelity solution of the full compressible Navier--Stokes equations in the nearfield and a portion of the acoustic field; the radiated sound is extrapolated from a Kirchhoff surface adjusted for mean flow.
Habibi, K., Lew, P., and Mongeau, L., “Prediction of sound absorption characteristics of orifice plates with mean flow using the lattice Boltzmann method,” Paper 4pEA6 presented at the st meeting of the Acoustical Society of America, Seattle, Washington, May 23 – 27,Abstract published in Journal of the Acoustical Society of.
A linear eddy subgrid model for turbulent combustion - Application to premixed combustion. SURESH MENON, PATRICK MCMURTRY and; Numerical prediction of aerodynamic noise radiated from low Mach number turbulent wake.
CHISACHI KATO, AKIYOSHI IIDA, Modeling and computation of turbulent free-surface jets. MINER, M. STEWART and. Full text of "NASA Technical Reports Server (NTRS) Transonic Symposium: Theory, Application, and Experiment, volume 1, part 2" See other formats. FEDSM Prediction of Aerodynamic Noise Radiated From a Vertical-Axis Wind Turbine.
Iida, A. / Mizuno, FEDSM Effects of Dimple Size and Depth on Golf Ball Aerodynamic Performance. FEDSM Anaytical Study of the Oscillating Channel Flow Solution With Application to the Turbulent Case. Poroseva. Journal of Sound and Vibration() State prediction of an entropy wave advecting through a turbulent channel flow.
Journal of Fluid Mechanics () A fast second-order accurate method for a two-sided space-fractional diffusion equation with variable by: The object of this book is to provide engineers and researchers in the wind power industry, national laboratories, and universities with comprehensive, up-todate, and advanced design techniques and practical approaches.
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Optimization and application of riblets for turbulent drag reduction. Aerodynamic prediction of conventional missiles using component build-up techniques. Prediction of centerline shock-layer thickness and pressure distribution on delta wing-body configurations / (Washington, D.C.: National Aeronautics and Space Administration: [For sale by the Clearinghouse for Federal Scientific and Technical, Springfield, Virginia ], ), by George E.
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The aim of our study is to specify positions of the sound sources and to clarify how they are created in turbulence and how the sound is emitted from them, in terms of the aerodynamic sound theory. For the first step, we numerically reproduce the jet oscillation as a sound source and the edge tones as a product simultaneously for 2D and 3D.
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Whitmore.Full text of "Aeronautical Engineering A special bibliography with indexes, supplement 7" See other formats.into the category of classical acoustics, whereas the sound generated by turbulent flow or the unsteady aerodynamic forces on propellers falls into the domain of aeroacoustics.
A main feature of aeroacoustics is the large difference between the energy levels of the unsteady flow fluctuation and the sound.
This is true even for a very loud noise.