Experimental generation and investigation of Peregrine breather waves in deep water

Abstract

ABSTRACT The modulation instability is a prominent explanation for the occurrence of nonlinear freak waves. The modulation instability could be described by the famous nonlinear Schrödinger (NLS) equation. The Peregrine breather solution of the NLS equation is usually adopted as a prototype in freak wave simulation. The freak waves based on the Peregrine breather solution (Peregrine breather waves) are characterised by huge wave crests, large wave heights and concentrated energies. In this paper, the Peregrine breather waves are experimentally generated in deep water. The specific experimental wave-making procedure is first proposed. The measured wave elevations show great agreement with the analytical solutions. Moreover, the modulation instability scenario is observed by wavelet analysis. The effects of wave parameters on wave energy distributions are first analysed. The results indicate carrier wave amplitude and wave height determine the width of focusing energy frequency and carrier wave frequency determines the duration of focusing energy.