Energy of the Sea Craft Contour — Anomalous Wave System

Abstract

The article is devoted to a numerical study of the contour - anomalous wave system and the quantitative estimates of its energy parameters. The author discovered that the profile of an anomalous wave undergoes the following stages: the initial profile, the profile with the first maximum height, the two-humped profile, the profile with a second maximum height, and the breaking profile. The problem is solved by CFD method in three stages. At the beginning the density maximum of the kinetic energy and its position on the anomalous wave profiles was calculated. It was discovered that the anomalous wave profile with the second maximum has the highest energy density and presents the greatest danger to the contour stability. Then, the numerical studies demonstrated that the kinetic energy increased as we approached the time of the anomalous wave collapse. It was discovered that the sum of the kinetic and potential energies is reduced due to the dissipation associated with the physical and turbulent viscosity. Eventually, we calculated the contour capsizing work. It was revealed that the anomalous wave energy loss corresponded to the contour capsizing work and increased with the vessel displacement. The relative value limit of the anomalous wave energy losses on bad moving contour reached 40 %. The received results can be used, firstly, for development of CFD based numerical studies. Secondly, the results can be used as the database for improvement of the design of the vessels, and also as a motive to search for causes of shipwrecks of vessels over 27000 tons, which did not capsize due to anomalous wave.