From the analysis of a set of airborne images of ship wakes, we show that the wake angles decrease as U(-1) at large velocities, in a way similar to the Mach cone for supersonic airplanes. This previously unnoticed Mach-like regime is in contradiction with the celebrated Kelvin prediction of a constant angle of 19.47° independent of the ship's speed. We propose here a model, confirmed by numeri...

This paper presents responses of an edge circular cantilever beam under the effect of an impact force. The beam is excited by a transverse triangular force impulse modulated by a harmonic motion. The Kelvin-Voigt model for the material of the beam is used. The cracked beam is modelled as an assembly of two sub-beams connected through a massless elastic rotational spring. The considered problem ...

Artificial spin ice, made up of planar nanostructured arrays of simple ferromagnetic bars, is a playground for rich physics associated with the spin alignment of the bars and spin texture associated with the magnetic frustration at the bar vertices. The phase diagram is exotic, showing magnetic monopole-like defects and liquid and solid phases of spins arranged in loop states with predicted chi...

We show that low-order g-modes with large enough amplitudes to affect significantly the solar neutrino fluxes would produce surface velocities that are 10 times larger than the observed upper limits and hence are ruled out by existing data. We also demonstrate that any large-amplitude, short-period oscillations that grow on a Kelvin-Helmholtz time scale will require, to affect solar neutrino fl...

a School of Public Health, Sun Yat-sen University, Guangzhou 510080, China b Key Laboratory of Tropical Disease Control, Ministry of Education, Guangdong Provincial Research Center for Severe Infectious Prevention and Control Technology, Guangzhou, China c Zhongshan Institute of School of Public Health, Sun Yat-sen University, Zhongshan, Guangdong Province, China d School of Public Health and S...

The equatorial Kelvin wave is destabilized by cross-equatorial shear in a rather bizarre fashion. There is no well-defined inviscid neutral curve. Instead, using an exemplar the linear shear U(y) = 2y where U is the mean zonal flow and y is nondimensional latitude, the Kelvin wave is unstable for all 2, however, small. We show through multiple precision numerical calculations that the imaginary...