Cabin noise analysis of polar transport vessels under ship‒ice‒water‒air coupling continuous icebreaking based on the S-ALE algorithm

Abstract

With the increasing number of ships navigating in polar regions, collisions between ships and sea ice are inevitable. The cabin noise problem caused by ship-ice collisions is significantly different from that of ships navigating in open water, and it seriously affects the comfort and safety of shipboard personnel. To explore the transient cabin noise response caused by ship-ice collisions, this paper performs numerical studies of the ice load, compares the ice resistance values of experimental and empirical formulas through the ship-ice-water‒air coupled collision method, and gives the sound source load excitation. Then, in the frequency domain acoustic analysis, the acoustic response of the typical cabin noise under icebreaking excitation and coupling excitation is calculated by using the acoustic-structure coupling analysis model and statistical energy analysis model, respectively. The effect of ship transient cabin noise on personnel comfort is analyzed according to the standard of ship noise. The results show that the transient cabin noise is scattered from the collision position to the stern at a certain angle and decays along the length, width, and superstructure of the ship as the frequency increases. The transient cabin noise under coupled excitation shows an M-shape distribution in the ship ranges. The icebreaking excitation mainly affects the transient cabin noise within 1000 Hz, with strong nonlinearity at a low-frequency band. The sound source excitation has a more obvious effect on the cabin noise in the middle-high frequency bands. The A-weighted sound pressure level of transient cabin noise in accommodation cabins and wheel houses during icebreaking operations of polar ships exceeds 5–20 dB(A) of the standard limit, which seriously affects the comfort of people on board. The research results of this paper can provide a reference for the study of ship-ice collision-induced transient cabin noise and the formulation of relevant standards.