Analysis and challenges in Bubble Curtain Technologies

The increasing demand for renewable energy has incited an increase in the evolveing rate of offshore wind energy. To meet the demands, more offshore wind power generators are being installed in the sea, where the air currents are stronger. The majority of the foundation of wind turbines uses mono piles.The installation process of the mono-piles supporting the wind turbines often includes foundation piles,driven into the seabed, using hydraulic impact hammers or vibratory devices. The pile in- stallation, that is an essential component in the erection of wind farms,has a thwarting by-product : the underwater noise pollution. Continuous high frequency sounds produced by the deformation of the shell of the pipe while it is being hammered to the sea bottom, can exceed 200 dB re 1μ Pa . Pile driving using impact hammers in open water increases the likelihood that marine mammals suffer disturbance or even instantaneous death, which lead to the implementation of new legislation. The aim of this thesis is to asses: (key points) 1. State of the art in sound attenuation during pile driving operations. 2. Sound characteristics, Attenuation, Soil Models, Response. 3. Perforated Pipe Analysis. 4. Macro, Micro, Nano bubbles.