Numerical investigation on the effect of trim on ship resistance by RANSE method

This paper presents the results of study effect of trim on resistance of US Navy Combatant DTMB 5415 model at three different drafts and two Froude numbers by using unsteady RANSE method in conjunction with towing tank tests. Firstly, the numerical results at zero trim condition were verified and validated with experimental data. Then, a series of resistance curves for different trim conditions at different drafts and speeds were performed to produce data source to evaluate the influence of trim on ship resistance. Results denote that the changing tendency of total ship resistance at different trim conditions varying with speed and draft combinations, and the variation of pressure resistance component due to trim is considerably larger than frictional resistance component. Finally, the paper provides details of flow characteristics around ship like wave patterns on free surface, pressure distribution and skin friction on the hull surface, and free water surface in order to explain the physical phenomenon of changing ship resistance at different trim condition.