Acoustic interferometer

About: Acoustic interferometer is a research topic. Over the lifetime, 1493 publications have been published within this topic receiving 19355 citations.

Reflection and refraction of acoustic waves at the boundary between the ferromagnetic Heusler alloy and liquid

Abstract: Reflection and refraction of quasi-longitudinal and quasi-transverse acoustic waves at a flat interface between a liquid and a ferromagnetic crystal of the Heusler alloy Ni2 + x + y Mn1 − x Ga1 − y (in the region of its premartensitic and martensitic phase transitions) is considered. The directions of propagation and polarization and the amplitude of reflected quasi-longitudinal and quasi-transverse and of transmitted longitudinal waves in the (110) plane of the crystal are determined. In a wide region of phase transformations of this alloy, the possibility is shown of using temperature to efficiently control the angles of reflection and refraction of wave modes and the coefficients of their conversion due to a colossal acoustic anisotropy of the crystal. Beginning from a certain critical angle of the quasi-transverse wave, the quasi-longitudinal wave arising upon reflection acquires the nature of the accompanying surface vibration and at a large proximity to phase transition can be emitted into the bulk of the crystal. On the basis of the available experimental data for Ni2MnGa crystals, numerical estimations of the above acoustic effects have been carried out.

Influence of non-homogeneous uniaxial pressure on the propagation of bulk acoustic waves in crystals

Abstract: The development of the theory of propagation of small amplitude bulk acoustic waves in crystals under uniaxial mechanical pressure has been made by taking into account the condition of non-homogeneous deformation of crystal sample. It has been shown that the path of bulk acoustic waves will be a function of the non-homogeneous deformation. As an example, calculations for some crystal directions of cubic crystal Bi/sub 12/GeO/sub 20/ (23 point symmetry) have been made.

Interferometric investigation of laser-supported absorption waves

Abstract: Interferometry of laser-supported absorption waves and the resulting gas dynamic disturbances are studied. It is possible to show the propagation of shock, geometri cal shapes of the waves and vaporization of target material.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Numerical Simulation of Acoustic Waves in a Two-Dimensional Phononic Crystal: Negative Refraction

Abstract: The lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in water. Lens effect is observed by the negative refraction of acoustic waves, which results in refocusing of the waves at the point outside the crystal. To increase the focal intensity, we introduce a 2D phononic crystal shield with a different composition of material, which returns the incident waves back to the lens via the perfect reflection. Also, the dependence on filling fraction of metal in the crystal is studied.

Energy dissipation in a sound wave in the presence of evaporation and condensation at a surface

Abstract: We consider the transmission and absorption of plane and spherical acoustic waves in the presence of evaporation and condensation at a flat surface. A sound absorbing device is considered as an example.