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"The relative significance ofthe parallel middle body and stern form in the wake formation of single-screwlarge ships and their contribution to the ship?s viscous resistance are studied by using computational fluid dynamics (CFD). A10450-DWT tanker is considered by varying the ratio of theparallel-middle-body?s length to the ship?s length (Lmb/L) and by varying the shape of the stern form from aV-like to a U-like underwater stern transom section. In all the calculations,the principal dimension and the displacement of the ships are kept constant. Alarger value for the parallel-middle-body relative length (Lmb/L) of ships with the same stern form results in alarger drag coefficient but does not affect the nominal wake fractionsignificantly. A change in the shape of the underwater stern form,from a V-like to a U-like section, results in a much larger drag coefficientascribed to the much larger wake fraction. The stern form dominantly affectsthe nominal wake fraction and the ship?s viscous resistance compared to theparallel-middle-body relative length."

"The relative significance of the parallel middle body and stern form in the wake formation of single-screw large ships and their contribution to the ship’s viscous resistance are studied by using computational fluid dynamics (CFD). A 10450-DWT tanker is considered by varying the ratio of the parallel-middle-body’s length to the ship’s length (Lmb/L) and by varying the shape of the stern form from a V-like to a U-like underwater stern transom section. In all the calculations, the principal dimension and the displacement of the ships are kept constant. A larger value for the parallel-middle-body relative length (Lmb/L) of ships with the same stern form results in a larger drag coefficient but does not affect the nominal wake fraction significantly. A change in the shape of the underwater stern form, from a V-like to a U-like section, results in a much larger drag coefficient ascribed to the much larger wake fraction. The stern form dominantly affects the nominal wake fraction and the ship’s viscous resistance compared to the parallel-middle-body relative length."

"The effects of the application of a stern hydrofoil on ship resistance were studied numerically using computational fluid dynamics (CFD) and were verified using data from model tests. A 40 m planing-hull Orela crew boat, with target top speed of 28 knots (Froude number, Fr = 0.73), was considered. The stern foil (NACA 64(1)212) was installed with the leading edge positioned precisely below the transom with angle of attack of 2 degrees at elevation 0.853 T below the water surface (where T is the boat’s draft). At relatively low speed (Fr < ~0.45) the application of a stern foil results in an increase in ship resistance (of up to 13.9%), while at relatively high speed (Fr > ~0.55) it results in a decrease in ship resistance (of up to 10.0%). As the Froude number increases, the resistance coefficient (CT) first increases, reaches a maximum value, and then decreases. Its maximum value occurs at Fr ? 0.5, which is consistent with the prediction of a resistance barrier at approximately this Froude number."