Experimental analysis of bow flare slamming and whipping responses in a ship at different sailing speeds

Abstract

This study conducted an experimental investigation using a segmented model to determine bow flare slamming loads and whipping responses of a ship in regular waves. The model simulated the distribution of the vertical and horizontal bending stiffnesses of the hull. A continuous wavelet transform was employed to capture temporal variations in the harmonic components. The influences of sailing speeds on the temporal and spatial variations in the slamming pressures in the bow flare were analyzed. Subsequently, the time-frequency characteristics and asymmetry of the global responses under different test conditions are discussed. The random errors in the experimental system were investigated through repeated testing. The findings revealed that a higher sailing speed could significantly influence the magnitude and distribution of slamming pressures on the bow flare, while playing an important role in inducing asymmetric slamming loads under oblique waves. The slamming-induced whipping responses under regular waves caused considerable periodic changes in the strengths of the harmonic components around the wet natural frequency of the model. At high sailing speeds, the whipping responses significantly increased the asymmetry of the vertical bending moment (VBM) at midship.