相关论文: The best whistler: a cavitating tip vortex

Forced excitations at frequencies in the range of the first order azimuthal spin waves of a magnetic disk in the vortex state are known to scatter into the vortex gyration mode, thereby allowing the growth of Floquet spin waves forming a…

Precession is a unique motion in which the orientation of the rotational axis of a rotating body is not fixed but moving, and it generally exists in the Universe from giant stars through tiny atomic nuclei. In principle, the precession of…

Traditionally, the occurrence of cavitation has been related to the ratio between flow velocity and pressure gradient in the case of hydrodynamic cavitation, or some combination of vapor pressure and surface tension. However, both…

Acoustic invisibility of a cloaking system in turbulent uids has been poorly understood. Here we show that evident scattering would appear in turbulent wakes owing to the submergence of a classical cloaking device. The inherent mechanism is…

Numerical simulation has indicated that vortex structures can exist for a long time in the form of quantized filaments on arrays of coupled weakly dissipative nonlinear oscillators in a finite three-dimensional domain under a resonant…

We investigate the flow generated by a magnetic stirrer in cylindrical containers by optical observations, PIV measurements and particle and dye tracking methods. The tangential flow is that of an ideal vortex outside of a core, but inside…

Fluid dynamics video: Snapping shrimp produce a snapping sound by an extremely rapid closure of their snapper claw. Our high speed imaging of the claw closure has revealed that the sound is generated by the collapse of a cavitation bubble…

Spinning neutron stars, when observed as pulsars, are seen to undergo occasional spin-up events known as glitches. Despite several decades of study, the physical mechanisms responsible for glitches are still not well understood, but…

A model for the acoustic production of gravitational waves at a first order phase transition is presented. The source of gravitational radiation is the sound waves generated by the explosive growth of bubbles of the stable phase. The model…

Cicadas (Homoptera:Cicadidae) are insects able to produce loudly songs and it is known that the mechanism to produce sound of tymballing cicadas works as a Helmholtz resonator. In this work we offer evidence on the participation of the…

Expressive singing voice correction is an appealing but challenging problem. A robust time-warping algorithm which synchronizes two singing recordings can provide a promising solution. We thereby propose to address the problem by canonical…

We propose an experiment for directly constructing and locally probing topologically entangled states of superconducting vortices which can be performed with present-day technology. Calculations using an elastic string vortex model indicate…

We (re)cosider the propagation of small disturbances (sound waves) in the presence of a pinned irrotational vortex in a superfluid with the help of the formalism of acoustic spacetimes. We give closed formulas for the scattering angle for…

Cavitation has historically been related to parameters measured at equilibrium, such as vapor pressure and surface tension. However, nucleation might occur when the liquid is metastable, especially for fast phenomena such as cavitation…

Scientists collaborating internationally have developed a new way to learn about our universe through gravitational waves, which are ripples in space-time caused by the motion and vibration of celestial bodies. By analogy, gravitational…

We consider a two-dimensional wave system containing a subwavelength hole, such as an aperture in an interface supporting surface electromagnetic or acoustic waves, or an island in a fluid surface sustaining gravity-capillary waves. Recent…

Self-oscillations underlie many natural phenomena such as heartbeat, ocean waves, and the pulsation of variable stars. From pendulum clocks to the behavior of animal groups, self-oscillation is one of the keys to the understanding of…

We describe a novel phenomenon in which vortices are produced due to resonant oscillations of a scalar field which is driven by a periodically varying temperature T, with T remaining much below the critical temperature $T_c$. Also, in a…

The gravitational radiation produced by binary black holes during their inspiral, merger, and ringdown phases is a promising candidate for detection by the first or second generation of kilometer-scale interferometric gravitational wave…

Vortex, the winding of a vector field in two dimensions, has its core the field singularity and its topological charge defined by the quantized winding angle of the vector field. Vortices are one of the most fundamental topological…