Abstract
In the wave tank facilities at the Technical University of Berlin, a series of comprehensive experiments were conducted to evaluate the feasibility of an innovative offshore fish cage design. This pioneering structure comprises several distinct cylindrical sections, each fully submerged and constructed from highly flexible membranes and fish netting. The different sections are fixed with a flexible but more rigid structure. This model is used to determine the feasibility of a full-scale model, that due to its large dimensions and near-the-surface operation, will be subjected to heavy responses and forces in demanding sea states.
The experimental setup consists of a motion capture system, that coupled with other sensors such as force gauges, allowed to track and evaluate the motion of the submerged structure as well as the wave hydrodynamical loads that it was subjected to. The primary objective of this experimental campaign was to evaluate the dynamic response of this flexible body to various wave conditions, encompassing both single regular waves and wave spectra. Different angles of attack of the body were tested with the aim of being able to cover as much variety of responses of the body as possible. Finally, the research assesses the applicability of conventional rigid-body motion analysis techniques, such as the response amplitude operator to this intricate flexible system. This paper presents the first results of what will be an in-depth analysis of these body motions in waves. Identifying, as a result, the heave motion of the mentioned underwater flexible body.
