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

Observation of the Wave Effect on Ship Manoeuvring Coefficients based on Numerical PMM Approach
Zhang Zhu, Byung-Soo Kim, Shuguang Wang, Yonghwan Kim
Department of Naval Architecture & Ocean Engineering, Seoul National University
Seoul, Korea

Rankine panel method to estimate the wave drift force/moment of ship
static drift tests. Lee et al. (2021) proposed a bilinear model to enhance
the two-time-scale model, and the work has discussed the importanceof understanding the wave effect on manoeuvring coefficients. The
recent ITTC (2021) also proposed the suggestion about carrying out thePMM tests in waves and observing the wave coupling effects.

ABSTRACTThis study is to investigate the wave effect on ship manoeuvring
coefficients by carrying out a series of PMM tests under waves. The
static drift test at different drift conditions and the dynamic PMM test
at different motion frequencies have been carried out, and three regularwaves including short, intermediate, and long waves are considered.
The wavelength effect is compared with respect to the PMM motion
conditions, and the further investigation is to observe the manoeuvring
coefficients under these wave effects. The numerical model which isbuilt based on CFD method is applied as an alternative to theexperimental tank facility.

effect; CFD.

In this study, the numerical PMM tests in waves are carried out using aCFD solver that implements the ship coupled motion of prescribed
PMM movement and wave-induced pitch and heave. The regular waves
that cover short, intermediate and long waves at constant wave slope
are considered for the ship motion. Present work selects two typicalmotions, the static drift motion and the harmonic yaw motion, to show
the wave effect on the PMM motion as well as the corresponding
manoeuvring coefficients.

INTRODUCTIONTEST OVERVIEW

Ship manoeuvring motion has been a complicated topic that is not only
about ship manoeuvring quality but also is related to environmental
conditions such as wind and current, water finite depth, and waves. The
traditional research works are mainly proposed based on the calm sea
condition. One of the typical methods for investigating the shipmanoeuvrability is the captive PMM tests that generate shipmanoeuvring coefficients under various specified static or periodicalmotions. As nowadays more and more focus has been on the shipmanoeuvrability coupled with incident wave field. The current work
aims to perform a series of PMM tests under wave conditions tounderstand the wave effect on the manoeuvring coefficients.

Numerical ModelFor the works on the ship static drift motion or harmonic PMM motion
in waves. Yasukawa and Adnan (2006) carried out the static drift test
under the head and beam sea conditions to estimate the ship drift forcesand drift moment. Xu et al. (2007) conducted the pure sway test in head
wave conditions and observed the force components at different wave
frequencies and wave heights. Yasukawa et al. (2010) applied the strip
theory to predict the ship static drift motion in waves, considering thelaterally drift effect. Lee and Kim (2020) applied the time-domain

where ρ, u, p are the density of fluid, velocity, and pressure,respectively; Tτ is the deviatoric stress tensor of incompressible flow
and fext is the external forces including gravity.

KEY WORDS: PMM in waves; manoeuvring coefficients; wave

The numerical model is built by using the PMM module of thesnuMHLFoam program which is an in-house package developed basedon the open-source OpenFOAM-v1906 platform. The continuity
equation and momentum equations are given as follows.

 u  0(1)( u ) ( u  u )  p    T   f ext
t(2)A moving circular domain of radius 0.5L+2λ is used with a surrounding
wave forcing region near the boundary, as shown in Fig. 1. The
waves2Foam toolkit (Jacobsen et al., 2011) is applied to ensure theexponential forcing function based on volume-of-fraction (vof) method.

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