Fluid-Structure Interaction Analysis of Multiple Wingsails

Abstract

The maritime sector contributes around 3% of CO2 emissions. The International Maritime Organization (IMO) has a net-zero emission goal for the maritime sector by 2050. This goal has forced the industry to develop more environmentally friendly propulsion solutions, while wind-assisted ship propulsion is an alternative solution for sustainable shipping. This thesis investigates the aerodynamic performance and fluid-structure interaction (FSI) among multiple wingsails with crescent-shaped profiles. A two-way coupled FSI simulation framework was developed by using computational fluid dynamics (CFD) integrated with finite element analysis (FEA). The CFD simulations were performed using improved delayed detached eddy simulation (IDDES). The FEA was based on a simplified structural model, where the wingsails are regarded as solid bodies, and the tip displacement due to global bending was focused. The arbi- trary Lagrangian-Eulerian (ALE) approach was implemented with mesh morphing based on radial basis function (RBF). FSI and CFD simulations are performed for three apparent wind angles (AWA): 60, 90, and 120 degrees. Results revealed that the wingsail closest to the bow of the ship experiences higher aerodynamic forces and stronger flutter than the other sails closer to the stern, indicating more critical flow. It was also found that the FSI has considerable negative effects on the thrust generation. This study is expected to provide guidance on wingsail structural design and multiple wingsail arrangements.