Comparison of EFD and CFD results of the free surface flow field about the series 60 C_B chemical bounds 0.6 ship

摘要

Series 60 C_B chemical bounds 0.6 represents an important class of ships for which vast amount of experimental data is available. Thus, it represents an ideal test bed for validating Computational Fluid Dynamics (CFD) codes. The code UNCLE incorporates the recnently introduced algorithm for tracking unsteady free surface flows in a times accurate manner. In this algorithm, facilitate the tracking of the free surface, a bqackground grid is employed. Using the background grid the free surface grid noints are forced to move along predetermined paths in order to simplify the grid regneneration process at the new time level. Newton's method is used to find the intersection of the background grid lines with the free surface. This allows to preserve the shape of the free surface during various grid operations at a given time level. The governing equations of thf flow field are cast with respect to an unsteady Eulerian coordinate system and solved using the modifed artificial compressibility method. The resulting numerical algorithm is implicit and time accurate and is formulated based on a finite volume approach. Roe's formulation is used for obtaining the first order invsicid numerical fluxes and van leer's MUSCL approach is used for obtaining higher order (thir) corrections. Central differencing is used for the viscous terms and a two point backward EAuler formula is used for the time drivative. The same algorithm is also used for implicitly solving the free surface kinematic condition which is cast with respect to surface curvilinear coordinates. The numerical results are compared with the experimental results. The flow conditions are Fr chemical bounds 0.316 and Re chemical bounds 4,020,000. The results are quite encouraging.