Aeroacoustic measurements experimental fluid mechanics. Takeda, Journal of Fluid Mechanics, Vol. , ) From the Back Cover The goal of aeroacoustic measurements is to provide a basis for assessing mechanisms of noise generation, and to develop methods
Aerodynamic Sound Emission as a Singular Perturbation M. S. Howe, Contributions to the theory of aerodynamic sound, with application to excess jet noise and the theory of the flute, Journal of Fluid Mechanics, 10.1017/S0022112075002777, 71, 04, (625), (2006).
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: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
Jan 01, 2011 · 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. We show that, by filtering the flow field by means of a linear convolution filter, it is possible to decompose the flow
Noise due to fully developed turbulent flow exhausting Jan 08, 1976 · REFERENCES 1. H. G. DAMES and J. E. FFOWCS WILLIAMS 1968 Journal of Fluid Mechanics 32, 765-778. Aerodynamic sound generation in a pipe. 2. G. F. KUHN 1974 University of Southampton Seminar (25 October 1974). Noise transmission and radiation from pipes excited internally by acoustic waves and/or fully developed turbulent flow. (Unpublished.) 3
Numerical Prediction of the Sources and the Modal Journal of Computing and Information Science in Engineering; Journal of Dynamic Systems, Measurement, and Control This shows that satisfactory accuracy can be obtained with state-of-the-art computational fluid dynamics (CFD) codes if care is taken with the simulation setup. Aerodynamic Sound Generation in a Pipe,
A numerical investigation of the aeroacoustic characteristics of the flow past a circular cylinder is presented for Reynolds numbers in the range 2.67 × 10 4 3.67 × 10 5, which falls within the upper subcritical and critical regimes.This is based on computational fluid dynamics simulations using a delayed detached-eddy simulation model for the aerodynamics of the near-field, which feeds
Prediction of the aerodynamic sound generated due to flow Jan 28, 2020 · Analysis of sound generated due to a laminar flow past a circular cylinder subjected to the mean rotation along with the rotary oscillating motion has been performed for the Reynolds number Re = 150 and the Mach number M = 0.2.The direct numerical simulation approach has been used to study modifications in the generated sound field over a range of forcing parameters using disturbance
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.
Aug 30, 2007 · The results of an experimental investigation of sound generation by the interacting toroidal and oblique vortices formed in a subsonic turbulent jet under the action of saw-tooth finite-amplitude sound waves with simultaneous longitudinal internal and transverse external excitation are presented (the sound pressure level on the jet edge is 165175 dB). The direct schlieren method with
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. 180 171-191
Study on Mechanism of Aerodynamic Sound Generation by Flow 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
Mar 08, 1985 · Journal of Sound and Vibration (1985) 99(1), 111-120 AERODYNAMIC SOUND GENERATION CAUSED BY VISCOUS PROCESSES F. OBERMEIER Max-Planck-Institut fiir Strungsforschung, Btingerstrasse 4-8, D 3400 Gtingen, Federal Republic of Germany (Received 21 February 1984, and in revised form 12 May 1984) With the aim of resolving some questions arising