Comparison of Various Spatial Discretization Schemes in Numerical Simulation for Ship Airwakes

Abstract

For numerical simulation of ship airwake by CFD, based on the use of an unstructured grid, the k-ε turbulence model and SIMPLE algorithm, the characteristic features of complex fluid flows eg recirculation zones and strong vortex fields in the aircarft operating region of a generic 3D frigate model was presented. The accuracy of the predication was checked by performing calculations on different grid sizes and comparing with wind-tunnel flow visualization data. A comparison of several typical spatial discretization schemes was performed. y+ values were also tested. The general features of the flow predicted in this paper compare reasonably well with experimental data. However, CFD simulation produced a higher velocity in the vicinity of vortex zone when compared to experimental data. Obvious differences exist between results by first-order upwind scheme (power law scheme) and second-order upwind scheme (QUICK scheme, third-order MUSCL scheme). Second-order upwind scheme (QUICK scheme, third-order MUSCL scheme) are recommended for the CFD simulation of ship airwakes with a modest increase in computational cost. y+ values from o (10) to o (1000) can all be accepted for the CFD simulation of ships (e.g., SFS1 ) with Reynolds number 108 or more.