A high-order fractional step finite volume solver towards prediction of longitudinal distribution of cross-sectional ship roll hydrodynamics

Abstract

A high-order fractional step finite volume solver is developed with a fractional step method along with an explicit fourth-order Runge–Kutta scheme in solving Navier–Stokes equations. And then the solver is applied to the prediction of the longitudinal distribution of cross-sectional ship roll hydrodynamics. The present development ameliorates the previous high-order finite volume solver [Ocean Eng 180:119–129] in solving the pressure–velocity coupled equation to further enhance its robustness on roll simulation. Firstly, accuracy of the solver is validated by shear-driven cavity flows and a series of roll motions with the available published numerical or experimental results. And its convergency is verified with a grid- and time step-dependence study. Then, a roll simulation on the mid-section of a KVLCC2 is performed; it embodies that the present solver can suppress the force oscillation than the previous one [Ocean Eng 180:119–129]. Finally, harmonic excited roll motions for several cross sections of a KVLCC2 are systematically investigated for cases of different roll amplitudes and frequencies. And longitudinal distributions of roll hydrodynamics and flow structures near the ship hull are analyzed. In results, the present solver enhances the robustness on roll simulation compared with the previous one [Ocean Eng 180:119–129]. Roll hydrodynamic coefficients culminate at sections of the parallel middle body, and decrease gradually towards fore and aft, and then they increase at the bow and stern.