Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Study on the influence of cross wave on ship motion characteristics based on computational fluid
dynamics
Yu Lu, Wu Shao, Zhuhao Gu, Chunxiao Wu and Chuang Li
Naval Architecture and Ocean Engineering College，Dalian Maritime University
Dalian, Liaoning Province, China（Yildirim et al.,2019）. As a special rogue wave, the square wave hasa deep influence on the ship movement.
In order to study the effect of waves on ship motion, the problem ofwave generation needs to be solved first, that is, to simulate andreproduce all kinds of waves on the sea in a numerical pool. It isimpossible to know whether the existing technology is reliable only
through numerical simulation, and then to verify the accuracy ofnumerical waves through error analysis of experimental
methods(Ducrozet et al., 2016). However, most of the waves on the sea
are rogue waves, so it is particularly important for the development of
the wave technology in the pool(Cao,2014; Xia,2014). On the basis of
the existing research, Hu(2015) proposed the wave train superposition
model based on probability and the second-order nonlinear solution
based on the respiratory subsolution, simulated different types ofmalformed waves by using a numerical wave flume, and carried out indepth research on their interaction with structures (such as cylinders andplates).Although several theories have been proposed to explain theformation of rogue waves, the mechanism is still unclear. In the real sea,
the interactions between wave and current is a factor that cannot beignored, and the existence of current will have an important influence on
the parameters, propagation and shape of wave(Peng, 2014).
Benetazzo(2013) used the ocean coupling-atmosphere-wave-sedimenttransport (COAWST) modeling system to study the influence of thewave current interaction (WCI) process in the semi-enclosed Venice Bay(northern Adriatic Sea) on waves. In fact, the formation of cross sea isalso caused by the interactions of wave and current.
RANS method is a common method to study ship seakeeping(Jiaoet al. , 2020), and in the case of cross sea, this method is still reliable.
The earliest research on intersecting waves started from Toffoli etal.(2006). They mainly analysed the influence of s-wave on the safe
navigation of ships and the causes and countermeasures of safety
accidents. Onorato et al.(2013) conducted a series of experiments onlarge waves in the ocean based on the nonlinear Schrodinger equationand studied in detail the abnormal phenomena generated by the collisionof two groups of rogue waves. Liu(2018) studied the breaking wave
phenomenon after the intersection of two wave propagation directions.
By setting up a cross two channel device in the pool, it can make thewaves of the two directions of propagation propagate through theirrespective channels, and meet and break in a specific area of the physicalprocess. By changing the angle between the two channels, it canexperiment the influence of different angles on the broken wave. In theABSTRACT
Cross sea is a kind of deformed wave with strong nonlinear.
Different weather patterns cause the ocean to have two systems ofcurrents that are at least 45 degrees in different directions, when waves
from two different weather patterns meet, they form square, crisscrossed
waves. Based on CFD numerical simulation method, the intersecting
wave is simulated numerically. Firstly, the wave height of the cross wave
numerical simulation and the wave variation curve of the theoreticalvalue with time are basically consistent with the trend of wave variation,
which verifies the reliability of the numerical simulation. Then, thenavigation condition of DTMB5415 ship under a certain cross wave isstudied by using this numerical pool, and the waves on the water surface
are analyzed emphatically. The wave height variation values of somefixed points around the ship are compared with the theoretical values,
and the reasonable comparison results are obtained. Finally, the ship
motion response characteristics under different parameters of cross wave
are studied. The research shows that the motion characteristics of ships
are closely related to the combined direction angle and wavelength ofcross wave.
KEY WORDS: Computational fluid dynamics; Cross sea; Seakeeping
performance; Nonlinear; Irregular wave; Volume of Fluid; ship motion
characteristics.

INTRODUCTION
Ship and ocean engineering equipment in the security and stabilityof the extreme sea condition problem increasingly prominent, especiallyin the north sea, the black sea, South Africa, the east China sea, the seaof Japan, China, south China sea and Taiwan strait, and many other sea
area, the deformation of the observed wave more because of its
instantaneously, powerful and unpredictability constitute a serious threat
to the safety of the Marine structures. The cross sea is a very typicalrogue wave. It is caused by the meeting of two waves coming fromdifferent directions due to complex weather and sea conditions, when theangle between the two waves is 90°, the resulting wave is called a crosssea. Rogue waves have very strong energy and can be very destructive
to Marine structures, especially ships. Since ancient times, there havebeen frequent risk accidents on the sea. Although some of them arecaused by human factors, most of them are caused by bad sea conditions

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