Drag analysis of different ship models using computational fluid dynamics tools

Abstract

Drag analysis based on CFD (computational Fluid Dynamics) simulation has become a decisive factor in the development of new, economically efficient and environmentally friendly ship hull forms. Recently, computational Fluid Dynamics (CFD) has been experiencing rapid advances due to both computer technology progress and efficient algorithms that have been developed to solve the Navier-Stokes(N-S) equations used in the flow analysis around ship hulls. Three-dimensional finite volume method (FVM) based on Reynolds averaged Navier-Stokes equations (RANS) has been used to simulate incompressible flow around two conventional models namely Wigely parabolic and Series 60 hull in steady-state condition. Different turbulence models such as Standard k- ε, Realizable k-ε and Shear stress transport (SST) k-ω are used with standard wall function to measure the drag coefficient. It is observed that k-ε turbulence model shows better performance than any other model. The numerical solutions of the governing equations have been obtained using commercial CFD software package FLUENT 6.3.26. Model tests conducted with these two models are simulated to measure various types of drag coefficient at different Froude numbers. The numerical results in terms of pressure coefficient and drag coefficient for different Froude numbers have been shown graphically or in the tabular form. The agreement between the numerical results and the experimental indicates that the implemented code is able to reproduce correctly the drag coefficient, pressure field, velocity field and the free-surface elevation around the Wigely parabolic and Series 60 hull. Velocity vectors as well as contour of pressure distribution have also been displayed graphically. The computed results show good agreement with the experimental measurements/numerical results at a Froude number below 0.3.