비선형파를 고려한 비대선의 선수선형설계와 저항성능

초록

This paper presents the relation between bow hull form and nonlinear waves around the stem by using the results of numerical simulations and model tests. For the numerical simulations, Navier-Stokes equations and continuity equation are used for governing equations, and the equations are computed by finite difference method in a rectangular mesh system with variable staggered type. Also the free-surface is tracked by marker-density method(program IUBW). A Series 60(CB=0.6) hull form is used for the validation of the present numerical simulation method. For the hull form design, Series 60(CB=0.8) is chosen as a parent ship, and several bow bulbs are attached on the stem, keeping the global bow type as it was. Kracht's charts are applied to get parameters which determine the bulb type. The wave pattern and pressure distribution on each designed hull surface are simulated to predict the resistance performance of that by the marker-density method. Also, model tests are performed for the several cases among the designed hulls. These results show that the bow bulb will improve the resistance performance by reducing the characteristics of wave resistance. It is expected that the present research results regarding nonlinear waves and the geometry of the fore body of ship will facilitate better hull form design productivity at preliminary full ship design stage.