## aerodynamic sound generation in a pipe journal of fluid

### 12345NextAERODYNAMIC WHISTLES - JSTOR

Aerodynamic sound generation has been the subject of experiment and theo retical study for more than a century.In the course of these investigations novel whistles have been discovered and math ematical descriptions have been devel oped (notably by Vincenz Strouhal of Czechoslovakia and by Lord Rayleigh of Britain).Aerodynamic sound generation by turbulent flow in the Mar 01,1970·Aerodynamic sound generation by turbulent flow in the vicinity of a scattering half plane.Williams,J.E.Ffowcs.; Hall,L.H.Abstract.Publication Journal of Fluid Mechanics.

### Aerodynamic sound generation in a pipe Journal of Fluid

Mar 28,2006·Abstract.The paper deals with the problem of estimating the sound field generated by a limited region of turbulence in an infinitely long,straight,hard-walled pipe.The field is analysed in aAerodynamics of flue organ pipe voicingorgans,pipe voicing,organ building,conservation,1.Introduction Associating the term aerodynamics with an activity which always has been considered as the culprit of craftsmanship and artistry in organ building may seem a little respectless at first,yet it is a fact that organ pipesAnalysis on Physical Mechanism of Sound Generation inside Analysis of coupling aerodynamics and acoustics are performed to investigate the self-sustained oscillation and aerodynamic noise in two-dimensional flow past a cavity with length to depth ratio of 2 at subsonic speeds.The large eddy simulation (LES) equations and integral formulation of Ffowcs-Williams and Hawings (FW-H) are solved for the cavity with same conditions as experiments.

### Boundary conditions for direct computation of aerodynamic

May 17,2012·Boundary conditions for direct computation of aerodynamic sound generation. Sound generation by flow over a two-dimensional cavity. AIAA Journal,Vol.33,No.3.Direct computation of the sound from a compressible co-rotating vortex pair.26 April 2006 Journal of Fluid Mechanics,Vol.285,No.-1 Broadband sound generation by confined turbulent jets The Jul 31,2002·Sound generation by confined stationary jets is of interest to the study of voice and speech production,among other applications.The generation of sound by low Mach number,confined,stationary circular jets was investigated.Experiments were performed using a quiet flow supply,muffler-terminated rigid uniform tubes,and acrylic orifice plates.A spectral decomposition method based on a Characteristics of a pulsating jet through a small Davies,H.G.,and Fflowcs Williams,J.E.(1968). Aerodynamic sound generation in a pipe, J.Fluid Mech.32,765 778.Google Scholar Crossref; 12.Diebold,B.,Delouche,A.,Dumée,J.P.,Guglielmi,J.P.,Delouche,P.,and Péronneau,P.(1990).

### Cited by 1010Publish Year 1970Author J.E.Ffowcs Williams,L.H.Hall(PDF) Flow decomposition and aerodynamic sound generation

An approximate decomposition of fluid-flow variables satisfying unbounded compressible NavierStokes equations into acoustically radiating and non-radiating components leads to well-defined sourceCited by 1010Publish Year 1970Author J.E.Ffowcs Williams,L.H.HallSound generation by steady flow through glottis-shaped The Journal of the Acoustical Society of America 116,1720 (2004); and dipolelike sources due to the force applied by the vocal folds onto the surrounding fluid are the two primary broadband sound generating mechanisms. Aerodynamic sound generation in pipe, J.Fluid Mech.32,765 Cited by 24Publish Year 1985Author F.ObermeierSound Generation - an overview ScienceDirect TopicsSound generation by bends and joints in ventilation ducts has been measured by Bullock [71] using much the same techniques as Kuhn and Morfey [45] for pipes and reduced to correlations as in Chapter 4 of Volume 1.Namely,the duct discharged into a reverberant room and an equivalent value of sound power inside the duct was calculated using standard end corrections.

### Cited by 35Publish Year 2011Author Samuel Sinayoko,A.Agarwal,Z.HuAerodynamic sound generation by turbulent flow in the

Mar 29,2006·Abstract.The presence of the edge of a half plane in a turbulent fluid results in a large increase in the noise generated by that fluid at low Mach numbers.The parameter which is important is the product $2k\overline {r}_0$,where $\overline {r}_0$ is the distance of the centre of an eddy from the edge.Eddies which satisfy the inequality $2k\overline {r}_0\ll 1$ have the sound output of the quadrupoles associated with the fluidCited by 5Publish Year 1976Author G.F.Kuhn,C.L.MorfeyAerodynamic sound generation caused by viscous processes Mar 08,1985·The continuity equation can be rewritten as v ,u- 1 dS- I dp- 1 dS-_1 dw (6) cp dt yp dt R dt a2 dt' AERODYNAMIC SOUND AND VISCOSITY 113 where a is the speed of sound,c,and cthe specific heats and y = cP/ c Eliminating V - u from equation (5) and from equation (6) then gives 0(w+2Ju12)=-at(R ddS a2 dt,) (L-TVS)+viscousterms.Cited by 75Publish Year 1968Author H.G.Davies,J.E.Ffowcs WilliamsFlow decomposition and aerodynamic sound generation Dec 03,2010·An approximate decomposition of fluid-flow variables satisfying unbounded compressible NavierStokes equations into acoustically radiating and non-radiating components leads to well-defined source terms that can be identified as the physical sources of aerodynamic noise.

### Computational aeroacoustics of phonation,Part I

Oct 25,2002·The aerodynamic generation of sound during phonation was studied using direct numerical simulations of the airflow and the sound field in a rigid pipe with a modulated orifice.Forced oscillations with an imposed wall motion were considered,neglecting fluidstructure interactions.Direct Numerical Simulation of Woodwind Aeroacoustics[2] Yoshikawa S,Tashiro H,Sakamoto Y.Experimental examination of vortex-sound generation in an organ pipe A proposal of jet vortex-layer formation model.Journal of Sound and Vibration.Vol.331; 2012.p.2558-2577.[3] Howe M.S.Contributions to the theory of aerodynamic sound,with application to excess jet noise and the theory of the flue.Flow decomposition and aerodynamic sound generation -adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A

### Flow decomposition and aerodynamic sound generation

Flow decomposition and aerodynamic sound generation 339 source is expressed as a (nonlinear) function of only the non-radiating components it is free of the dependent (radiating) variables.Therefore,this source should represent the true source of aerodynamically generated soundFlow-Induced Acoustics in Corrugated Pipes In the model,the acoustic response of the corrugated pipe is simulated by connecting the lossless medium moving with a constant velocity with a source based on a discrete distribution of van der Pol oscillators arranged along the pipe.Our time accurate solutions exhibit dynamic behavior consistent with that experimentally observed,including the lock-in frequency of vortex shedding,standing waves and the onset fluidInteraction between compressible fluid and sound in a flue Oct 16,2014·The mechanism of sound generation from an unsteady motion of fluid flow with non-zero vorticities,i.e.,aerodynamic sound,and that of sound absorption due to the interaction with the fluid flow,have attracted many authors' attention in the fields of fluid dynamics,aeroacoustics and acoustics (Howe 1998),since Lighthill put an acoustically analogous interpretation on the generation of aerodynamic

### Interaction between compressible fluid and sound in a

aerodynamic sound is generated from the oscillating jet rather than the vortices shed by the collision of it with the edge of the mouth opening,namely vortex shedding.(Some gures may appear in colour only in the online journal) The Japan Society of Fluid Mechanics Fluid Dynamics ResearchInvestigation of the sound generation mechanisms for in Sound generation due to an orifice plate in a hard-walled flow duct which is commonly used in air distribution systems (ADS) and flow meters is investigated.The aim is to provide an understanding of this noise generation mechanism based on measurementsMitigation of aerodynamic sound for a laminar flow past a Jul 23,2020·A new arrangement of splitter plates has been proposed for the mitigation of aeroacoustic noise generated by the two-dimensional laminar flow over a square cylinder at the Reynolds number Re = 100 and the Mach number M = 0.2.The proposed arrangement involves a pair of cowl plates (arc-shaped splitter plates) symmetrically positioned on either side of the wake center-line near the rear corners

### Noise due to fully developed turbulent flow exhausting

Jan 08,1976·1.INTRODUCTION Noise in flow-ducts can be generated by acoustic sources such as fans,compressors or valves.Aerodynamic turbulence inside the pipe,however,can also generate acoustic power (see,for example,reference [1]).Numerical study on edge tone with compressible direct A two-dimensional model of the edge tone is studied by a highly accurate and reliable method of direct numerical simulation of the compressible Navier-Stokes equations,and used to verify key featuOpen Journal of Fluid Dynamics - ResearchGateOpen Journal of Fluid Dynamics.Publisher Aerodynamic Sound and Flow Field Generated from Combinational Inclined Tapered Cylinder It is thought that small hydropower generation is

### Pressure-based integral formulations of LighthillCurle's

Apr 14,2017·Journal of Sound and Vibration.Volume 393, H.S.Ribner,Aerodynamic Sound from Fluid Dilatations A Theory of the Sound from Jets and Other Flows,University of Toronto,Institute of Aerophysics,1962. H.G.Davies,J.E.Ffowcs-WilliamsAerodynamic sound generation in a pipe.Proposed Inflow/Outflow Boundary Condition for Direct Proposed Inflow/Outflow Boundary Condition for Direct Computation of Aerodynamic Sound.J.B.Freund; J.B.Freund.Stanford University,Stanford,California 94305 Journal of Fluid Mechanics,Vol.726 POD analysis of sound generation by a turbulent jet.Research on the numerical simulation of aerodynamic noises 2.LEE of computational aero-acoustics.It could be assumed that density fluctuation ' / was very small in acoustic phenomenon and the magnitude ( ' / ) c 0 of pulsating quantity u ' of fluid velocity related to wave propagation was also very small.Through analysis,it showed that the basic equations of fluid motion could be linearized to describe the motion of sound wave.

### Sound Generation by Low Mach Number Flow Through Pipes

Jan 25,2014·In addition,the unsteady flow through the pipe,the aerodynamic sources,and the spectra of sound are evaluated numerically.Here effects of different numerical algorithms (PISOPIMPLE) and of different numerical boundary conditions at the outlet of the pipe (advective,convectivewave transmissive) are identified and discussed.Sound generation in corrugated tubes - IOPscienceApr 03,2009·Nakamura Y and N Fukamachi 1984 Sound generation in a Magic Pipe,J.Jpn Soc.Fluid Mech.Nagare 3 199-203 (in Japanese) Google Scholar Nakamura Y and T Matsukawa 1987 Vortex excitation of rectangular cylinders with a long side normal to the flow,J.Fluid Mech.180 171-191Study on Mechanism of Aerodynamic Sound Generation byFlow visualization,particle image velocimetry (PIV),and fluctuating static pressure measurements were carried out simultaneously in a turbulent shear flow separated from a sharp-edged fence to estimate the probable location of the sound source that is closely related to vortex motion and aerodynamic sound generation.The measurement of the fluctuating static pressure is an effective way to

### The characteristics of the turbulence in the mixing region

Measurements in the mixing region of a 1 in.diameter cold air jet are described for Mach numbers ranging from 0.2 to 0.55.The statistical characteristics of the turbulence in the first few diameters of the flow may be expressed in terms of simple kinematic similarity relationships.

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