The “Wave Bridge” for bypassing oceanic wave momentum

• Published in: Journal of ocean engineering and marine energy 2015-11, Vol.1 (4), p.395-404
• Main Authors: Timmerberg, Sebastian, Börner, Thomas, Shakeri, Mostafa, Ghorbani, Reza, Alam, Mohammad-Reza
• Format: Article
• Language: English
• Subjects: Coastal Sciences; Engineering; Engineering Fluid Dynamics; Mechanical Engineering; Oceanography; Offshore Engineering; Renewable and Green Energy; Research Article
• ISSN: 2198-6444; 2198-6452
• DOI: 10.1007/s40722-015-0028-0

Here, we introduce and investigate the concept of the Wave Bridge that can bypass the momentum of oceanic waves about ocean objects. The Wave Bridge is composed of a wave energy absorber on the upstream side of an ocean object, and a wave maker on its downstream side. The wave absorber and the wave maker are mechanically connected in such a way that the wave energy absorbed on the upstream side is simultaneously used by the wave maker downstream of the ocean object to generate waves. The Wave Bridge therefore protects the ocean object from waves by transferring incident wave energy from the upstream to the downstream. Furthermore, since the wave absorbed upstream is the same as the one generated downstream, the corresponding horizontal forces are equal in magnitude and opposite in sign and hence cancel each other, resulting in a zero net horizontal force on the Wave Bridge and its supporting structure. Our experimental results show a wave protection efficiency of up to 97 % and a horizontal force protection efficiency of up to 80 %. We also investigate the effect of the finite height of the Wave Bridge and the resulting wave energy leakage underneath the plungers on the overall protection efficiency. The Wave Bridge and its variants may reduce the costs of offshore structures by reducing the wave loads, provide calm water in the midst of an energetic ocean for future offshore cities, and conserve energy of dynamic position systems by reducing the wave-induced disturbances of vessels.