Mohammad-Reza Alam

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Here we show that floating objects in stratified fluids can be cloaked against broadband incident waves by properly architecting the bottom corrugations. The presented invisibility cloaking of gravity waves is achieved utilizing a nonlinear resonance concept that occurs between surface and internal waves mediated by the bottom topography. Our cloak bends(More)
The fact that acoustic radiation from a violin at air-cavity resonance is monopolar and can be determined by pure volume change is used to help explain related aspects of violin design evolution. By determining the acoustic conductance of arbitrarily shaped sound holes, it is found that air flow at the perimeter rather than the broader sound-hole area(More)
It has been reported worldwide that muddy seafloors can extract a significant fraction of the energy stored in overpassing ocean waves within several wavelengths. We consider a synthetic-seabed-carpet, supported by multiple springs and generators, that should extract wave energy the same way as muddy seafloor does. This paper presents the analytical model,(More)
Here we show that weakly nonlinear flexural-gravity wave packets, such as those propagating on the surface of ice-covered waters, admit three-dimensional fully localized solutions that travel with a constant speed without dispersion or dissipation. These solutions, that are formed at the intersection of line-soliton mean-flow tracks, have exponentially(More)
We consider a class of higher order (quartet) Bragg resonance involving two incident wave components and a bottom ripple component (so called class III Bragg resonance). In this case, unlike class I/II Bragg resonance involving a single incident wave and one/two bottom ripple components, the frequency of the resonant wave, which can be reflected or(More)
We investigate, via perturbation analyses, the mechanisms of nonlinear resonant interaction of surface-interfacial waves with a rippled bottom in a two-layer densitystratified fluid. As in a one-layer fluid, three classes of Bragg resonances are found to exist if nonlinear interactions up to the third order in the wave/ripple steepness are considered. As(More)
We develop a direct numerical method to study the general problem of nonlinear interactions of surface/interfacial waves with variable bottom topography in a twolayer density stratified fluid. We extend a powerful high-order spectral (HOS) method for nonlinear gravity wave dynamics in a homogeneous fluid to the case of a two-layer fluid over non-uniform(More)
Mohammad­Reza Alam, Yuming Liu and Dick K. P. Yue Journal of Fluid Mechanics / Volume 689 / December 2011, pp 529 ­ 540 DOI: 10.1017/jfm.2011.448, Published online: 08 November 2011 Link to this article: http://journals.cambridge.org/abstract_S0022112011004484 How to cite this article: Mohammad­Reza Alam, Yuming Liu and Dick K. P. Yue (2011). Attenuation of(More)
Prediction is a central goal and a yet-unresolved challenge in the investigation of oceanic rogue waves. Here we define a horizon of predictability for oceanic rogue waves and derive, via extensive computational experiments, a statistically converged predictability time scale for these structures. We show that this time scale is a function of the sea state(More)