The nonlinear interaction of shear Alfvén waves and gradient-driven instabilities on pressure gradients in the Large Plasma Device (LAPD) [Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] at UCLA is explored. Nonlinear response at the beat frequency between two shear Alfvén waves is shown to resonantly drive unstable modes as well as otherwise damped modes. Resonantly driving the damped mod...

The AUFS-scheme by Sun and Takayama is a flux splitting scheme without breakdown of discrete shock profiles, usually called carbuncle, but still with a fine resolution of entropy waves. Unfortunately, in numerical tests, the viscosity on entropy waves turns out to be too small and the viscosity on shear waves to be too high. In this paper, we provide fixes to overcome these deficiencies.

Fluctuations in the crack tip structure should result in the release of elastic waves that propagate both into the bulk as well as along the surface. Ramanathan and Fisher (1997), and Morrisey and Rice (1998) examined such wave interactions in a series of increasingly sophisticated models. The possibility that in-plane and out-of-plane perturbations could persist along the crack surface, result...

We present numerical simulations of a flow in a rapidly rotating cylinder subjected to a time-periodic forcing via axial oscillations of the sidewall. When the axial oscillation frequency is less than twice the rotation frequency, inertial waves in the form of shear layers are present. For very fast rotations, these waves approach the form of the characteristics predicted from the linearized in...

In this work, we explored the potential of measuring shear wave propagation using optical coherence elastography (OCE) in an inhomogeneous phantom and carotid artery samples based on a swept-source optical coherence tomography (OCT) system. Shear waves were generated using a piezoelectric transducer transmitting sine-wave bursts of 400 μs duration, applying acoustic radiation force (ARF) to inh...

Our objectives are to use both acoustic remote sensing and in situ profile observations of large amplitude internal waves, together with highly resolved numerical simulation, so as to develop a predictive understanding of their behavior, with application to their generation by flow past topography, their contribution to mass and momentum transport, mixing, modulation of near surface bubble clou...

INTRODUCTION The reflection and refraction of horizontally polarized shear (SH) waves by a frictional contact interface that can slip has been studied by the present authors [l-3] and Miller [4-6]. If the solids are sheared, the localized slip induced by the waves is more pronounced in one direction than in the other, which leads to the interesting phenomenon of the solids creeping with respect...

The strong inhomogeneities in plasma parameters in the ionosphere and adjacent regions can trap waves in the upper end of the ULF range (Pc1/Pi1). The topside ionosphere is characterized by a rapidly increasing Alfvén speed with a scale height the order of 1000 km. Shear mode Alfvén waves in this region can be partially trapped at frequencies in the 0.1-1.0 Hz range. The same structure can trap...

The treatment of kinetic shear Alfvén waves in homogeneous magnetized plasmas by means of Vlasov simulation is examined. To this end, the driftkinetic version of the Vlasov–Maxwell equations is solved via various numerical schemes, all employing a grid in (1 + 1)D phase space. Since kinetic shear Alfvén waves are Landau damped, the use of an equidistant grid in velocity space leads to a recurre...

S U M M A R Y The variation of frequency-dependent seismic wave attenuation with direction (attenuation anisotropy) contains additional information to that contained in velocity anisotropy. In particular, it has the potential to distinguish between different mechanisms that can cause velocity anisotropy. For example, aligned fracturing might be expected to cause measurable velocity and attenuat...