In this study, we tackle with one single effort, three fundamental problems in ship hydrodynamics, namely the attraction force exerted on a single ship moving rectilinearly close and parallel to a rigid wall（berthing...In this study, we tackle with one single effort, three fundamental problems in ship hydrodynamics, namely the attraction force exerted on a single ship moving rectilinearly close and parallel to a rigid wall（berthing）, the determination of the associated added-mass coefficients（maneuvering） and finally evaluating the forces exerted on a ship in a two-ship crossing scenarios. The novelty of the present approach relies on using Weinblum’s proposition to assimilate the ship’s hull by an ＂equivalent＂ tri-axial ellipsoid, as well as the employment of ellipsoidal harmonics expansion techniques.展开更多
A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic longitude and latitude was proposed.The vertical and horizontal geodesic coordinates measured with length were defined as coor...A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic longitude and latitude was proposed.The vertical and horizontal geodesic coordinates measured with length were defined as coordinate parameters,but the two families of coordinate curves were still meridians and parallel circles.The first fundamental form on the ellipsoidal surface and its three coefficients were deduced by the geodesic coordinate.The formula for the latitudinal scale factor of length for geodetic parallel lines was derived,by which the obtained result conformed to that standard value calculated from geodetic latitude,and it is applicable in the range of 400 km from north to south.Therefore,it lays the foundation for establishing the differential equation and differential relationship based on this type of coordinate parameters;and consequently,it is convenient and accurate enough to operate on the ellipsoidal surface in this new form of geodetic coordinate system.展开更多
文摘In this study, we tackle with one single effort, three fundamental problems in ship hydrodynamics, namely the attraction force exerted on a single ship moving rectilinearly close and parallel to a rigid wall（berthing）, the determination of the associated added-mass coefficients（maneuvering） and finally evaluating the forces exerted on a ship in a two-ship crossing scenarios. The novelty of the present approach relies on using Weinblum’s proposition to assimilate the ship’s hull by an ＂equivalent＂ tri-axial ellipsoid, as well as the employment of ellipsoidal harmonics expansion techniques.
基金supported by the National Natural Science Foundation of China(Grant No.40471114).
文摘A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic longitude and latitude was proposed.The vertical and horizontal geodesic coordinates measured with length were defined as coordinate parameters,but the two families of coordinate curves were still meridians and parallel circles.The first fundamental form on the ellipsoidal surface and its three coefficients were deduced by the geodesic coordinate.The formula for the latitudinal scale factor of length for geodetic parallel lines was derived,by which the obtained result conformed to that standard value calculated from geodetic latitude,and it is applicable in the range of 400 km from north to south.Therefore,it lays the foundation for establishing the differential equation and differential relationship based on this type of coordinate parameters;and consequently,it is convenient and accurate enough to operate on the ellipsoidal surface in this new form of geodetic coordinate system.
