by Division of Building Technology, Lund Institute of Technology in Lund, Sweden .
Written in English
|Series||Report / Lund Institute of Technology. Division of Building Technology -- 18, Report (Lund Institute of Technology. Division of Building Technology -- 18.|
|Contributions||Lund Institute of Technology. Division of Building Technology.|
|The Physical Object|
|Pagination||vii, 89 leaves :|
|Number of Pages||89|
Varying impedance boundary conditions on the barrier and constant impedance on the ground are assumed. Sound propagation over an infinite barrier with a constant cross-section for an harmonic point source is determined by solving 2D problems only, avoiding the computational complexity of the solution of a true 3D by: Propagation of sound close to the ground outdoors involves geometric spreading, air absorption, interaction with the ground, barriers, vegetation and refraction associated with wind and. Making use of an acoustic analogy, one is able to study the surface waves above a convex cylinder and, hence, to simulate the propagation of sound over an impedance ground in an upward refracting. Attenborough et al studied sound propagation through crops at short, i.e., 1m, and medium ranges, i.e., 10 and 20m. Excess attenuation data over m high wheat crops show that the presence of crops appears to inﬂuence the coherence of the ground-reﬂected sound. Due to the loss of coherence, the excess attenuation maximum gets distorted.
Journal of Sound and Vibration () 22 (1) SOUND REDUCTION BY BARRIERS ON THE GROUND H. G. JONASSON Division of Building Technology, Lund Institute of Technology, S 07 Lund, Sweden (Received 29 December , and in revised form 10 March ) An existing theory on the propagation of spherical sound waves over ground with a finite acoustic Cited by: Sound propagation over soft ground and through crops has been studied through outdoor measurements at short and medium ranges and through predictions. At lower frequencies, ground effect is dominant, and there is little or no attenuation due to crops. At higher frequencies above 3–4 kHz, the attenuation in crops is by: 6. The attenuation of sound propagated out‐of‐doors is conveniently separated into attenuation due to spherical divergence and excess attenuation due to atmospheric and terrain effects. This excess attenuation is principally caused by sound absorption in the air, the refractive effects of temperature and wind gradients, by turbulence and the effects of terrain and ground Cited by: One-way Sound Propagation: Breaking Acoustic Reciprocity In 2D Materials By: Mostafa Nouh on Febru Leave a Comment! 🤔 Figure 1: Simulation showing asymmetric acoustic wave propagations over a confined angular range within the 2D space of a thin : Mostafa Nouh.
In this book, the authors present current research in the study of the propagation, frequency and effects of sound waves. Topics discussed include time resolved visualisation and analysis on a single short acoustic wave generation; elastic vibrations of an isotropic plate with laser-induced atomic defects; sound velocity into turbulent medium; infrasound generation by turbulent Price: $ PROPAGATION OF SOUND AND FACTORS AFFECTING IT PROPAGATION OF SOUND Propagation of sound is the Transmission of Acoustic Energy through a medium via a sound wave. Sound is a sequence of waves of pressure, which propagates through compressible media such as air or water or solid. During their propagation, waves can be reflected,File Size: KB. Book Description. Predicting Outdoor Sound provides a scholarly yet practical examination of the phenomena that affect outdoor sound close to the ground and its prediction. It is devoted to bringing together theories and data to give both researchers and practitioners the basis for deciding which model to use in a given situation. Figure 1: Sound propagation over porous ground in relative levels (10 dB/division), (a) in octave bands between 63 and Hz and (b) from and Hz. HG= GFR= 20 MNs/m 4, and PG=GFR= kNs/ m 4, with Hs=5m and.