Session: 08-02-01 Maneuvering

Paper Number: 79450

79450 - NuMerical Investigation on Scale Effect of 5415M Maneuverability 

Abstract: A numerical investigation about the effect of ship model scale on turning and 20/20 zigzag maneuvers has been presented in this paper. A preliminary US Navy surface combatant, DTMB 5415M, is chosen as the object of study. An in-house CFD code HUST-Ship is used for the numerical simulation. Structured grid has been divided for the model and the use of overset grid technology allows the deflection of the rudders when the surface combatant undergoes 6 degrees of freedom motions. Numerical modelling errors for the simulation of steady turning at 35-degree deflection of DTMB 5415M rudder at Fr=0.41 in calm water have been estimated. The grid convergence studies have been conducted for the uncertainty analysis and the numerical results have been compared with the existed experimental data, which showed a good agreement. Three different scales (1:5, 1:15, 1:35.48) have been selected for the investigation to study the scale effects on ship turning. Ship motions, hydrodynamic forces and moments for all the scales have been compared for the purpose of analyzing the scale effects on ship maneuverability. The results show that larger scale has smaller tactical diameter and smaller roll angle. The results of intermediate scale are less than 5% compared with the smallest scale, and the difference between the largest scale and the smallest scale is more than 10%, especially the roll angle reaches 50%. The scales have different influence on forces coefficient and moment coefficient of different directions.
Keywords: CFD; DTMB 5415M; Turning; Overset grid; Scale effect.

Presenting Author: Donglei Zhang Huazhong University of Science and Technology

Authors:

Donglei Zhang Huazhong University of Science and Technology
Qing Wang Huazhong University of Science and Technology
Kai Dong Huazhong University of Science and Technology
Xianzhou Wang Huazhong University of Science and Technology