Experimental Investigation of Hull Lateral Force Distribution Using a Partly Captive Hydroelastic Model

Abstract

Experiments were carried out at the Institute for Marine Dynamics to determine the distribution of lateral forces and moments on a warship hull form with the objective of eventually modeling these components in a numerical maneuvering simulation. Total forces and moments were obtained from instrumentation included in IMD's horizontal Planar Motion Mechanism, and local shear forces, bending moments, and torques were measured at five locations along the instrumented elastic backbone of the segmented model. For modeling the maneuvering characteristics, interest centered on deriving the distribution of lateral force from these measurements. The test program consisted of varying the model static yaw angle and roll angle ( drift and heel) for a range of forward speeds in calm water at deep departure and operational light conditions. In most experiments the model was free to pitch and heave; however, the model was fixed in pitch and heave in a subset of the tests for comparison. This paper gives a general description of the model design, instrumentation, backbone calibration procedure, data collected and analysis procedure. Representative results illustrating the distribution of lateral force for a number of test conditions are provided along with some observations on their potential for modeling the maneuvering behavior of long slender vessels.