Isolating incident and reflected wave spectra in the presence of current

Abstract

It is vital for a variety of coastal and ocean engineering problems to understand the reflection characteristics of structures and devices. Various methods have been developed for wave-only cases, yet none have been demonstrated for wave-current conditions present in both the laboratory and real sea environments. A simple method to isolate wave reflections in collinear current is presented in this article, utilizing an established frequency-domain least-squares approach with a modified dispersion relation. The method has been tested numerically, before being applied to experimental data obtained at the FloWave Ocean Energy Research Facility. Typical wave spectra are generated in currents ranging from −0.3 m/s to 0.3 m/s. Results obtained demonstrate the method effectiveness whilst verifying that the assumptions are valid. The development of this method should enable reflection analysis to be performed for wave-current conditions with improved accuracy and greater confidence.