Effects of viscosity and nonlinearity on 3D flapping-foil thruster for marine applications

The present work focuses on the influence of viscosity, nonlinearities and 3D effects on the predicted performance of a submerged flapping wing. The computational tools used for the numerical investigation consist of in house computational fluid dynamics (CFD) and potential flow solvers. Numerical calculations obtained by both methods are presented over a range of motion parameters and compared against other methods and experimental data. Our analysis enlightens the importance of viscous, nonlinear and 3D effects to the operation of flapping foils. Additionally, a direct comparison between a CFD and a BEM solver is made highlighting the advantages and limitations of each method. The present methods could serve as useful tools for the assessment, preliminary design and control of the studied system for marine propulsion.