An analysis of practical RANS simulations for spinnaker aerodynamics

Reynolds-averaged Navier–Stokes (RANS) simulations were performed on 12 parametric spinnaker models which had been previously tested in a wind tunnel by the authors. Six different turbulence models were used on two of the sails: the standard k–ε, realizable k–ε, renormalization group theory (RNG) k–ε, standard k–ω, shear-stress transport (SST) k–ω and Reynolds stress (RS) models. The realizable k–ε model was the best in terms of both accuracy and robustness, and this model was used to predict the force coefficients for all 12 sails. In general, the results are good; however, the simulations fail to correctly predict the effect of camber on sail performance for beam and broad reaching conditions. Issues surrounding the convergence of the simulations are discussed, and suggestions for the practical use of RANS for spinnaker design and analysis are presented.