To obtain accurate soil parameters and improve the accuracy of acoustic-soil discrete element simulation model, we studied model’s parameter calibration. The test was carried out using measured acoustic velocity dominant frequency as response value (index). Firstly, Plackett—Burman scheme used to sensitivity ranking wave. that significantly affect wave were obtained: Shear modulus, Poisson’s ra...

Abstract Sound generating human activities so-called “anthropogenic sound” have increased ambient sound levels considerably in aquatic habitats that are markedly diverse in time and space. Sound generating human activities is now recognized as a potential driver of environmental changes in marine habitats. Iran has 750 km coastline along the Caspian Sea located in the north and around 2250 km ...

Sound field parameters are predicted with numerical methods in sound control systems, in acoustic designs of building and in sound field simulations. Those methods define the acoustic properties of surfaces, such as sound absorption coefficients or acoustic impedance, to determine boundary conditions. Several in situ measurement techniques were developed; one of them uses 2 microphones to measu...

In this work we solve the set of hydrodynamical equations for accretion disks in the spherical coordinates (r,θ,ϕ) to obtain the explicit structure along θ direction. We study a two-dimensional advective accretion disc in the presence of thermal conduction. We find self-similar solutions for an axisymmetric, rotating, steady, viscous-resistive disk. We show that the global structure of an advec...

Micro-perforated panel (MPP) can be used as non-fibrous acoustic absorber which can provide broadband sound absorption performance. In this study, a sub-structuring methodology based on the Patch Transfer Function (PTF) approach to deal with duct silencers with MPP absorbers and internal partitions is proposed, and the sound attenuation performance of such silencers is investigated. Reactive si...