3. Computation of Ship's Resistance Using an NS Solver with Global Conservation : Flat Plate and Series 60 (C_B=0.6) Hull :

A globally conservative NS solver for flow past a ship hull has been developed. It uses a 3rd-order accurate upwind differencing of the preprocessing (MUSCL) type for inviscid terms, in which the nonuniformity of grid spacing is taken into account. Using the solver, the drag of a flat plate at zero incidence was computed in the Reynolds number range Re=4.0 × 105 to Re=4.0 × 107The dependence of the drag on the degree of clustering of grid points was checked. The computed drag agreed with the Schoenherr value within 4%. An appropriate criterion for the minimum grid spacing Δmin adjacent to solid wall with this particular scheme seems to be Δmin= 0.005/ √Re.Then the drag of the Series 60 (CB=0.6) ship hull with the double model assumption was computed in the same Reynolds number range using grids with various Δmin and various degree of clustering toward bow and stern. Although the computed drag values showed some scattering among different grids, the results with the smallest Δmin agreed well with the measured values throughout the Reynolds number range.