Comparison between empirical and CFD based methods for ship resistance and power prediction

A comparative study is presented on ship hull resistance and propulsion power prediction using empirical formulations and a Computational Fluid Dynamics (CFD) based solution. The paper studies three benchmark ship hull models, two containers (KCS and DTC) and a tanker (KVLCC2) ship, using the commercial numerical tool, NavCad, and the open source CFD toolkit, OpenFOAM. Since experimental data for ship resistance are mostly available in model scale, validation of full-scale results generated using empirical formulations and CFD becomes difficult. Thus, model scale CFD simulation results were initially validated against the available experimental data in literature. Then, the CFD results were extrapolated to full scale for comparison with three methods based on different empirical formulations namely, series 60, Holtrop and Andersen. The results show reasonable agreement between NavCad and OpenFOAM results, indicating that in these cases NavCad simplified procedures yield sufficiently accurate results for different ship models with a substantially less effort and computational resource requirement than CFD models.