Numerical Simulation and Experimental Studies on Aft Hull Local Parameterized Non-Geosim Deformation for Correcting Scale Effects of Nominal Wake Field

Abstract

SummaryThe scale effects of an aft hull wake field pose a great challenge to propeller design and its performance prediction. Research into the characteristics of the scale effects and the subsequent correction of the errors caused by such effects play an important role in improving a ship's energy conservation and propulsion performance. For this research, using a KCS ship as the research target, the aft shape of an original ship model has been modified based on the smart dummy model (SDM) to change its nominal wake field. The present study explores the aft hull deformation of a KCS ship through a series of numerical calculations and validates the results using a similar ship model. In addition, wake field PIV-measurements are performed using particle image velocimetry to verify the corrected effects of the SDM. The SDM correction method offers a new pathway for correcting the errors associated with the scale effects in the nominal wake field measurements of a ship model.

Numerical Simulation of the Motion of a Large Scale Unmanned Surface Vessel in High Sea State Waves

“…The mesh refinement factor for the fine/medium and medium/coarse meshes was 1.22 and 1.17, respectively. The mesh refinement ratio of fine to medium (medium to coarse) grids was approximately 1.2, which was consistent with references [20]. The heave and pitch motion plots of USV at 7 level sea state with different meshes are shown in Figure 5.…”

“…The mesh refinement factor for the fine/medium and medium/coarse meshes was 1.22 and 1.17, respectively. The mesh refinement ratio of fine to medium (medium to coarse) grids was approximately 1.2, which was consistent with references [20]. The heave and pitch motion plots of USV at 7 The trimmed meshes and prismatic cell layers around the hull were generated using STAR-CCM+, and three sets of coarse, medium, and fine meshes of varying resolutions were generated and used for mesh sensitivity study.…”

The Effect of Hull Form Parameters on the Hydrodynamic Performance of a Bulk Carrier

“…Therefore, it was necessary to improve the accuracy of Holtrop and Mennen's empirical method according to the ship used in this study. In the process of correction for the empirical method of resistance, the toolbox commercial CFD software STAR CCM+ was used to calculate the total resistance of the parent ship at speeds of 9, 11, 13, 15, 17, 19, 21, and 23 kn, and the detailed experience and description of the numerical calculation strategy can be found in our previous research [42,43]. The total resistance was composed of friction and residual resistances.…”

Obtaining mathematical functions of the propeller thrust and torque coefficients fluctuations at non-uniform wake flow including geometry effects

“…Until now, several experimental tests and numerical studied are conducted to study of ship hull wakes by researchers [1][2][3][4][5][6][7][8][9][10][11][12]. In this regards, pressure distribution, open water characteristics and thrust fluctuation of conventional and highly skewed propellers under nonuniform wakes are studied numerically by Ghassemi [5].…”