Abstract As one of the boundaries ocean waveguide, acoustic properties seafloor sediments have been a hot research problem in propagation and field modeling. The existing has shown that sound velocity sediment is frequency dependent. In order to solve sedimentary speed dispersing often be ignored actual applications, this article uses parabolic Newton iterate dispersion equation obtain characte...

This paper discusses issues regarding in-situ methods of obtaining sound power at a point in a heating, ventilating and air-conditioning (HVAC) duct system. Such a method is being used as part of a larger investigation on acoustical prediction methods to allow for comparison of measured data to results from attenuation predictions of individual duct elements, such as elbows or dampers. Sound pr...

There are studies indicate that audible sound wave could have effects on propagation growth through catalyzing hearing sense organs, which would bring a series of physiological and biological chemistry reaction. The soundpressure level and frequency are important factors in propagation growth. In this study, an experimental system of audio generator was developed for investigating sound wave ef...

Abstract Electrorheological fluids (ER fluid) as an electrically controllable acoustic medium has been proved by experimental studies. In this paper, the sound attenuation in ER fluid at different propagation distances was experimentally studied. The results show that sound attenuation of ER fluid could be adjusted by the particle concentration of ER fluid and the intensity of electric field. A...

The Fourier pseudospectral time-domain method is an efficient wave-based method to model sound propagation in inhomogeneous media. One of the limitations of the method for atmospheric sound propagation purposes is its restriction to a Cartesian grid, confining it to staircase-like geometries. A transform from the physical coordinate system to the curvilinear coordinate system has been applied t...