DrillShip에서의 Thruster-Hull 상호작용에 관한 연구

Abstract

As many offshore companies continue to explore and develop deepwater resources, demand for drilling units designed for deepwater operations has increased. Along with conventional moored units, drillships, which are Dynamically Positioned(DP) vessels, are put into deepwater drilling projects. Drillships are getting more popular in industry because they offer enhanced station keeping ability during extreme weather conditions. The power estimation for DP system is essential process for designing drillships. When a thruster is attached to a hull, degradation in thrust is common, which is dependent upon the shape of the hull and the location of the thruster relative to the hull. Motivated by current trends and lack of required methodology with suitable data, the present study pursues the thruster-hull interaction in drillships. Thus the present paper suggest a reasonable approach to method of quantification of thruster-hull interaction without waves, and tested results for a selected set of drillship and thrusters. In this study, a drillship model that consists of two segments is manufactured. The model has one fore-hull and two different aft-hulls to compare the thruster degradations. Four azimuth thrusters are equipped and tested in several revolution conditions under consideration. The experimental results are normalized with the bare-hull tests.