Markus Brühl received his Diploma in civil engineering with specialisation in coastal engineering from Technische Universität Braunschweig, Germany, and his doctoral degree in civil engineering also from TU Braunschweig. Since his graduation, he has been working in different positions at TU Braunschweig and Coastal Research Center (FZK), Hannover, Germany, on the implementation and application of the nonlinear Fourier transform based on the Korteweg-deVries equation for the analysis of free-surface waves in coastal regions. Since May 2019, he has a position as postdoc in the group of Sander Wahls at TU Delft, The Netherlands, in order to continue with his research on development and application of nonlinear Fourier transform on free-surface water waves in shallow and deep water.
NFT FOR SHALLOW WATER WAVE DATA
The nonlinear Fourier transform (NFT) can be used in telecommunications and fiber optics, but also the propagation and modification of free-surface water waves can be analysed using NFTs. When waves propagate in shallow water, their behaviour is governed by the Korteweg-deVries equation (KdV). Waves in deep water can be described by the nonlinear Schroedinger equation (NSE). Therefore, by application of KdV- and NSE-NFT to water-wave data, the free-surface elevation can be decomposed into the underlying nonlinear spectral basic components and their nonlinear interactions. Even though the linear fast Fourier transform is the standard wave analysis method in coastal and ocean engineering at the moment, the results of KdV- and NSE-NFT clearly show significant advantages compared to the linear analysis results. At the workshop, an introduction to the application of NFT on water waves will be given and results will be presented that clearly show the advantage of this method compared to linear analysis.