GENERATION OF EXTREME TRANSIENT WAVES IN EXPERIMENTAL MODELS

Huichen Zhang, Markus Brühl

Abstract


The transfer of natural waves and sea states into small- and large-scale model teste contributes to the proper design of offshore and coastal structure. Such shallow-water ocean surface waves are highly nonlinear and subject to wave transformation and nonlinear wave-wave interactions. However, the standard methods of wave generation according to conventional wave theories and wave analysis methods are limited to simple regular waves, simple sea states and low-order wave generation without considering the nonlinear wave-wave interactions. The research project Generation of Extreme Transient Waves in Experimental Models (ExTraWaG) aims to accurately generate target transient wave profile at a pre-defined position in the wave flume (transfer point) under shallow water conditions. For this purpose, the KdV-based nonlinear Fourier transform is introduced as a continuative wave analysis method and is applied to investigate the nonlinear spectral character of experimental wave data. Furthermore, the method is applied to generate transient nonlinear waves as specific locations in the wave flume, considering the nonlinear transformation and interactions of the propagating waves.

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References


Brühl, Markus (2014): Direct and inverse nonlinear Fourier transform based on the Korteweg-deVires equation (KdV-NLFT). A spectral analysis of nonlinear surface waves in shallow water. Dissertation. Leichtweiß-Institut für Wasserbau, Technische Universität Braunschweig, Germany.

Brühl, Markus; Oumeraci, Hocine (2016): Analysis of long-period cosine-wave dispersion in very shallow water using nonlinear Fourier transform based on KdV equation. In: Applied Ocean Research 61, S. 81–91.

Osborne, Alfred R. (2010): Nonlinear ocean waves and the inverse scattering transform. 1. ed. Amsterdam: Academic Press (International geophysics series, 97).

Zhang, H.; Brühl, M. (2017): Generation of extreme transient waves in experimental model: Nonlinear Fourier transform of wave gauge data. International Short Course and Conference on Applied Coastal Research (SCACR2017), 3-6 October, 2017, Santander, Spain, 12 pp.




DOI: https://doi.org/10.9753/icce.v36.waves.51