Development of a fluid structure coupling for composite tidal turbines and marine propellers

Abstract

The recent strong development of composite blades for propellers and tidal turbines has been driven both by the reduction of mass compared to metallic materials and by the impact of the deformations of blades on the increase of their performances (as shown for instance in [1]). The gain in performances concerns the efficiency of the propeller or turbine, the mitigation of the risk of cavitation and, by extension, the reduction of noise and vibrations. In order to help the designer to make the appropriate choices during the early stages of the design, new numerical tools like a fluid-structure coupling for "heavy" fluid are necessary in addition to existing numerical and experimental methods. This paper focuses on the development of such a fluid-structure coupling algorithm for tidal turbines and marine propellers. The main objectives for the blades are: to get an accurate estimation of the deformations and stresses under a hydrodynamic load, to include these predictions in a design process in order to increase efficiency and reliability and finally to optimize the hydrodynamic shape and inner structure. In terms of software development the main target is to provide an efficient tool which can be integrated in an optimisation environment for preliminary to intermediate design phases, therefore with low resource consumption, fast execution time, easy file setup and fully scripted for an automated execution in command line.