Investigating the interaction of waves and currents from adcp field data

This paper characterises wave and current fields at two different marine energy site with investigation of WCIs (wave current interactions) and turbulence. The features of a 5-beam ADCP are utilised whereby it is found to accurately measure wave spectra up to high frequencies as well as providing directional wave data. Deployments were conducted in 2010 and 2011 using a Teledyne RDI 5-beam ADCP (Acoustic Doppler Current Profiler) recording waves and currents at 2Hz at the North Cornwall Wave Hub site in the UK. While the one conventional four beam 600 kHz unit ADCP was deployment at The Pentland Firth off the North coast of Scotland in March 2013. Current velocity off the North Cornwall coast is influenced principally by the semi-diurnal variation in tidal flow and by the regular cycle of spring and neap tides, with a maximum of 1 m/s Current Magnitude. The interaction between waves and currents has been studied and the important of the direction angle between wave of current has been under light in order to find appreciate interaction in the site. In the second site up of Scotland there are completely different sea state with the current magnitude up of 5 m/s where it is shows clearly the Doppler Shift effect and the wave direction influenced by the current. Most places in the world we can safely assume that the water velocity we measure is predominantly a superposition of waves and currents, but in the Penland Firth, The new assumption is that the measured velocity is really a superposition of waves, currents and turbulence, it is fundamental to investigate for the design of Marine Energy Converters (MECs).