Development of Free-Running Model Test Setup for a Damaged Surface Combatant in Heeled and Trimmed Condition

Abstract

For operations of naval vessels, prediction of maneuverability of the ships in various situation is one of the most important issue, even in damaged condition. In this study, maneuverability of a damaged surface combatant was examined by outdoor free-running model test. The test model was a tumblehome hull, designed by the Office of Naval Research. The damaged compartment for the test was designed according to the United States Navy regulations on survivability of naval combatants and located at the starboard of bow. An autopilot system was developed to control rudder angle and propeller revolution rate for the turning circle test and the zigzag test. Tests were conducted both in the intact and damaged conditions, to compare the advance speed change and maneuvering criteria. Tactical diameter of turning circle test to the damaged compartment was reduced, but effect of damage to reverse direction was relatively small. Damage caused reduction of turning speed in both direction. Motion response to change of rudder angle was delayed due to the damage. Sway velocity was reduced when the model turned to the direction of damaged compartment in zig-zag tests.