Wave resistance of slender body in unsteady motion under an ice sheet

Abstract

The paper is devoted to the theoretical study of the rectilinear unsteady movement of a slender body in a liquid near the free surface and an ice sheet. Water is an ideal incompressible liquid, and the motion of the liquid is potential. The ice cover is modeled by a floating viscoelastic plate. The viscoelastic properties of ice are described using the Kelvin–Voigt model. A slender body of a given shape in the liquid flow is modeled by the flow of the source-sink system. Various modes of body movement are considered: acceleration, deceleration, movement at a given speed. The effect of the ice sheet, acceleration and deceleration of the body on its wave resistance is analyzed. It is obtained that unsteady modes of motion (acceleration and deceleration) significantly affect the wave resistance of a slender body. Motion with low initial acceleration makes it possible to reduce amplitude of the first-time hump of wave resistance. During body deceleration to a full stop, the curve of wave resistance has an oscillations. Reduction of deceleration coefficient results in decrease of oscillation amplitude of wave resistance curve. The presence of the ice cover smoothes the hump of wave resistance during acceleration and reduces the number of oscillations and their amplitude during deceleration.