The influence of snow cover and the depth of the reservoir on the ability of hovercraft to destroy the ice cover by the resonant method when moving "front"

The results of studies of the possibilities of the resonant method of ice destruction implemented by amphibious hovercraft when they move across the ice at the speed of resonant bending and gravitational waves are presented. At this speed, the minimum frequency of bending vibrations propagating in a free floating plate coincides with the minimum phase velocity of gravitational waves. In this case, the Archimedean forces of support (buoyancy forces) are completely balanced by hydrodynamic forces, and the water ceases to support the ice sheet, i.e. its equilibrium is achieved only due to internal elastic forces arising in the plate itself. This leads to a sharp increase in the amplitude of the excited gravitational waves. The possibility of increasing the efficiency of the method of ice destruction due to the interference of resonant gravitational waves excited simultaneously by several amphibious hovercraft is considered. The results were obtained on the basis of experiments performed: in an ice basin; with large-scale models of amphibious hovercraft in the field; with full-scale amphibious hovercraft in various ice conditions, as well as using theoretical dependencies obtained for calculating the stress-strain state of the ice cover from the action of a moving load. When determining the ice-breaking capacity of vessels, changes in the depth of the reservoir and the presence of snow cover on the ice under conditions of bending-gravitational resonance were taken into account. A generalized Maxwell-Kelvin-Voigt model of deformation of a viscoelastic medium was used to describe the viscoelastic nature of the relationship between stresses and deformations in ice. The snow cover was modeled by a viscous layer. Dependences are given that make it possible to determine the increase in the thickness of the destroyed ice by the resonant method due to the simultaneous use of several vessels moving in front, i.e. when ships are located on a line perpendicular to their course. The dependences were obtained taking into account the effect of snow cover, reservoir depth and distance between vessels on the efficiency of the method of ice destruction.