Hydrodynamics of new high-speed surface systems

Abstract

Until recently, high-speed surface vessels consisted mainly of hydrogliders, airfoil boats, hydrofoil and air-cushion craft. Their hydrodynamic characteristics are well understood and the vessels involved have high speeds and excellent sailing qualities. In recent years, however, there has been some expansion of this group of vessels by means of high-speed surface objects on wheels (baggies) and tracks (snowmobiles), in some cases at speeds far exceeding those of hydrofoil and air-cushion craft. Information on the hydrodynamic characteristics of these vessels is not available in the literature. This prompts us to study their hydrodynamic parameters and to consider the practical use of these vessels. The report describes conditions for water rolling of wheeled and tracked systems with grousers, simulates this phenomenon, derives the dependence of draft and bearing capacity of wheeled systems on the Froude number, and presents the dependence of tracked traction on the dimensionless parameter equal to the ratio of absolute speeds of the lower part of a track and the above-water part of a model.