Short-term forecasting method of freak wave based on wave group characteristics under two-dimensional sea situation, and application

Abstract

The invention provides a short-term forecasting method of a freak wave based on wave group characteristics under a two-dimensional sea situation, and an application, and belongs to the field of shipsand ocean engineering. In order to solve the problem of accurate and rapid prediction of the freak wave, the short-term forecasting method comprises the following steps: step 1, obtaining a real-timemeasured ocean wave sequence; step 2: identifying and dividing wave groups in the measured ocean wave sequence based on a wavelet transform method; step 3: using it as a precondition of generating thefreak wave that the instantaneous frequency of an independent wave group and a BFI value of the wave group satisfy certain conditions, quickly calculating the evolution of the wave group in the manner of combining the wave theory with nonlinear schrodinger equation simulation, and finally judging whether the freak wave is generated. The short-term forecasting method provided by the invention hasthe effects of well separating the wave groups by processing wavefront information by using the wavelet transform, and then quickly calculating the evolution of the wave group in the manner of combining the wave theory with nonlinear schrodinger equation simulation so as to judge whether the freak wave is generated.

Description

technical field [0001] The invention belongs to the field of ships and ocean engineering, and relates to a method for avoiding sudden catastrophic sea waves for ships and ocean engineering. Background technique [0002] Wave is the most important dynamic load in ocean engineering, which plays a decisive role in the design and safe operation of ocean structures. In the actual marine environment, the deformed wave is a sudden catastrophic wave in the ocean. Operation and safety pose a threat, and even lead to the capsizing of ships and damage to marine structures such as offshore platforms, causing heavy casualties and economic losses. According to research, there are a large number of marine accidents caused by deformed waves every year. Therefore, how to predict deformed waves is a common goal pursued by the ship and ocean engineering industry and the scientific community. However, due to the late start of the research on freak waves and the complex generation mechanism, ...

AI Technical Summary

Problems solved by technology

In the traditional wave group identification method, the wave group is often determined by the continuous wave height of the wave train exceeding a certain threshold, which not only has certain human factors, but also cannot be accurately identified

At present, the main mechanism of deformed wave generation is: on the one hand, due to the dispersion focusing of waves, that is, the linear superposition of each wave component in the wave group evolution generates a deformed wave; on the other hand, due to the instability of wave modulation in the wave group evolution, that is, the carrier and edge When the band wave numbers are similar, the nonlinear effect causes the carrier wave to be affected by the disturbance sideband wave, and the amplitude of the wave train increases exponentially to produce a deformed wave

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