초기트림을 고려한 선박의 저항성능 연구

Abstract

The attitude of hull is changed by trim depend on pressure difference between bow and stern on cruising speed and various conditions. As ships proceed in confined water, squat phenomenon is occurred by pressure drop of bottom and difference of density. In addition, trim condition can be changed by cruising condition and the status of cargo loaded. In recent years, the shipowner requested resistance performance of hull on various condition to heavy industry. As such these case, change in attitude of the hull affect the resistance performance and it is important to predict.

In this paper, as the basic study for change in attitude, numerical calculations were carried out to predict components of initial trim resistance using FLUENT. Based on the concept of resistance components, the grand total resistance can be obtained by adding initial trim resistance component to total resistance component on calm water. In order to validate the numerical calculations, DTMB5415 and KRISO Container Ship model was chosen and numerical calculation was performed on fixed condition. The results were compared with the results of the CFD Workshop2005 and MOERI experiment data. Initial trim for KRISO Container Ship to draft bow and stern by constant was applied by varying and typical hull type of power yacht obtained through surveys was applied in the same way. Numerical calculations were performed for this condition due to the initial trim coefficient of residuary resistance changes investigated. The residuary resistance on initial trim condition is decrease due to increase the amount of stern trim.

By considering the initial trim, this study is expected to contribute initial design and optimization of hull.