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

Numerical prediction of maneuverability of Asymmetric Catamaran
Fengchao Yan a, Ang Li a, Yunbo Li b*a Marine Design&Research Institute of China, Shanghai, China;
b* College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai, China

initial stability formula of asymmetric catamaran and deduced theformula for calculating the initial stability height GM of asymmetriccatamaran (Jia et al., 2007).Huang et al. analyzed the vibration
performance of asymmetric catamaran, and studied the vibration
performance of asymmetric catamaran by analyzing and comparing withthe results of conventional catamaran by using the method of threedimensional finite element and empirical formula (Huang et al., 2007).
Liu Jia used LS Duna display nonlinear dynamic analysis software to
numerically simulate the attack of an asymmetric catamaran in regularwaves, studied the characteristics of water attack, and came to theconclusion that the main body is more prone to attack than the side bodywhen the ship has no initial roll, and the attack pressure will be greaterin the corresponding attack area (Liu Jia et al., 2010). Li et al. applied
the time domain panel method to solve the wave making problem ofasymmetric catamaran based on Green's theorem (Li et al., 2013). Li etal. continued to discuss the calculation method of wave making
resistance of asymmetric catamaran. They discussed the calculation
method of wave making resistance of asymmetric catamaran according
to the linear wave making theory, optimized the wave making resistancebased on the optimization platform, studied the interference law of side
body layout on ship wave making resistance, and selected the ship typelayout with the lowest wave making resistance (Li et al., 2013). The
influence of Dowson's free surface conditions on the navigation of theship in 2019 is discussed (Gong et al., 2019). Jiang Fan et al. (2021)
Based on the open source CFD solver open foam, numerically simulated
the fixed length rotary motion of the model under different rudder angles
and the Z-shaped motion under high rudder angles, and realized theprediction of the maneuverability of this kind of catamaran.
Due to the special ship shape structure of asymmetric catamaran, it isessential to study its maneuverability. In this paper, the separation modelis used to establish the ship maneuvering motion model to predict themaneuverability of asymmetric catamaran. The theoretical prediction
method and performance of asymmetric catamaran maneuvering motion
in still water are studied. Based on the research on the maneuvering
motion prediction methods of catamaran and trimaran, the hydrodynamic
derivative prediction method and maneuvering performance ofasymmetric catamaran are studied by selecting the three degree offreedom MMG model, using CFD technology and CFD software
STARCCM+. Without considering the interference of external factors

ABSTRACT
Combination with the hydrodynamic characteristics of the asymmetriccatamaran, the effects of asymmetric terms on the hydrodynamic
derivatives of the oblique towing motion, turning motion, and the higherorder coupled hydrodynamic derivatives are studied by CFD technology
based on the viscous fluid theory. Based on the MMG model, the turningand zig-zag maneuvers and related maneuvering motion parameters ofthe asymmetric catamaran are predicted and their characteristics areanalyzed. According to the results of numerical simulation, themaneuvering motion under positive rudder Angle and negative rudder
Angle is compared, and it is obtained that the side body of theasymmetric catamaran has obvious influence on the rotary motion and zshape motion, and the maneuverability prediction of the asymmetriccatamaran is realized.
KEY WORDS: Computational fluid dynamic(CFD); Asymmetriccatamaran; Maneuver; MMG model
INTRODUCTION
In recent years, high-performance ships have developed rapidly,especially catamarans and trimarans. Asymmetric catamaran is a new
type of high-performance ship in the early 21st century. Compared withthe traditional symmetric catamaran, the so-called asymmetric ship typerefers to the ship type in which the cross section of the hull forms anasymmetric shape below the design waterline. In addition to theadvantages of catamaran and trimaran in stability and large deck area,
this ship type also has the advantages of excellent seaworthiness and easy
parallel docking.
However, at present, although asymmetric catamaran yachts have beenbuilt, for example, the world's first asymmetric catamaran yacht named"Asian lady" made by Yantai Raffles shipyard in 2003, there are few
theoretical studies on such ship types. At present, there is a lack of
research on the hydrodynamic performance of asymmetric catamaran athome and abroad. In the last decade, the research on this kind of ship
type has mostly focused on stability, resistance and motion performance.
Jia et al of Dalian University of technology theoretically deduced the3815