Optimization of Viscoelastic Floating Membranes for Maximum Power Absorption Through Adjoint-Based Pde-Constrained Optimization

Abstract

Viscoelastic floating membranes can be used as flexible wave breakers to protect coastal and offshore structures or as flexible wave energy converters. Despite their potential, the optimal harvesting or dissipation of wave energy through viscoelastic floating membranes has not been explored. There is a lack of understanding of the impact of variable material properties on energy harvesting and dissipation of such materials, as well as the absence of optimization that considers irregular wave spectra. These gaps are addressed in this study, where we introduce an adjoint-based, partial differential equation (PDE)-constrained optimization framework, that leverages the finite element method to investigate and optimize the viscoelastic properties of membranes. This methodology allows for precise modulation of distributed design parameters such as the mass distribution, tension and damping, which are critical to the membrane's responsiveness to different wave conditions.The study demonstrates that optimizing both the distributed and uniform properties of the membrane under realistic sea states can lead to significant improvements in energy capture. This work not only assesses the effects of design parameters, but also proposes a new approach to designing viscoelastic floating membranes by focusing on the significance of distributed membrane properties.