SUMMARY Acoustic field analysis results of surface acoustic wave dispersive delay lines using inclined chirp IDTs on a Y-Z LiNbO 3 sub-strate are described. The calculated results are compared with optical measurements. The angular spectrum of the plane wave method is applied to calculation of the acoustic fields considering the anisotropy of the SAW velocity by using the polynomial approximati...

In this paper, a review of several features of the acoustic vector field will be presented. The theoretical foundation for the acoustic energy flow will be used to describe the concepts of the active and reactive components of the complex acoustic intensity field. Recently established phenomenology associated with the flow of acoustic intensity near planar boundaries via the visualization of st...

An analytical expression is derived for the temporal coherence of an acoustic field after multiple forward scattering through random three-dimensional (3D) inhomogeneities in an ocean waveguide. This expression makes it possible to predict the coherence time scale of field fluctuations in ocean-acoustic measurements from knowledge of the oceanography. It is used to explain the time scale of aco...

The structural changes in a magnetic fluid (formation of clusters) upon the effect of an external magnetic field were studied by acoustic spectroscopy. The properties of magnetic fluid dispersed in inhibited transformer oil ITO 100 have been studied by the analysis of changes in the acoustic wave absorption coefficient. The absorption coefficient of acoustic waves was measured as a function of ...

The time-dependent acoustic field generated by the mutual interaction of a pair of coaxial viscous vortex rings advecting along a common axis of symmetry is simulated using a two-step numerical procedure. In the first step, the flowfield is predicted by solving the incompressible Navier–Stokes equations. In the second step, Powell’s vortex sound theory is used to predict the far-field acoustic ...

the current study presents the results of the aerodynamic noise prediction of the flow field around a naca 0012 airfoil at a chord-based reynolds number of 100,000 and at 8.4 degree angle of attack. an incompressible large eddy simulation (les) turbulence model is applied to obtain the instantaneous turbulent flow field. the noise prediction is performed by the ffowcs williams and hawkings (fw-...