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

Application of fluid pressure field order reduction method in ship digital twin
Tao Lin1, Zhiyong Pei2 , Longhui Xiao1, Weiguo Wu2
1.Departments of Ocean Engineering, School of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology,Wuhan, Hubei, China
2. Green & Smart River-Sea-Going Ship Cruise and Yacht Research Center, Wuhan University of Technology,Wuhan, Hubei, China

which can reflect the whole life cycle of corresponding entities throughvirtual and real mapping, is gradually paid attention to. As a traditional
manufacturing industry, the degree of automation and digitalization isalso low. In the face of the trend of integration and upgrading withinformation technology, the application of digital twin technology to theshipbuilding field can improve the productivity, operation capacity andeconomic benefits of the industry.

ABSTRACTThe digital twin of the ship reflects the state and behavior of the entity inthe virtual space in real time through the mapping and interaction
between the ship's physical entity and the information virtual body.
Model reduced-order technology can transform high-order systems into
low-order systems, and realize real-time calculation and analysis of thesystem while ensuring accuracy, and provide efficient real-time virtual
mapping results for digital twin technology. Based on the proper
orthogonal decomposition (POD), this paper takes the flow velocity as
input variables, selects the pressure field on the surface of the plate toform the snapshot matrix, and performs the intrinsic orthogonal
decomposition of the snapshot matrix to obtain the model orthogonalbase. Then intercept a small amount of base that can reflect the main
characteristics of the model to establish the low-order governing
equations of the model, which can solve the surface pressure on the plate
under various working conditions in real time, and realizes the reducedorder processing of the CFD simulation model. The calculation results
show that the method in this paper is in good agreement with thetraditional CFD method, and the calculation efficiency is greatlyimproved while ensuring the accuracy. It can realize the real-time
analysis of the force on the plate, provide a research foundation for theestablishment of a ship fluid-structure coupling reduced-order model,
and provide technical support for driving the ship's digital twin.

Professor Michael Grieves (2003) first proposed the concept of a threedimensional mirror space model consisting of physical and virtual bodies
and the connection between them, which is regarded as the prototype ofthe future digital twin model. THE US Air Force Research Laboratory
and NASA jointly proposed the construction of the digital twin of future
aircraft, and defined the digital twin as a highly integrated multi-physicalfield, multi-scale, multi-probability simulation model for aircraft orsystems. Professor Tao Fei (2017) proposed the concept of digital twinworkshop for the first time, discussing the feasible method of two-way
circulation and interaction of data in the virtual and real world.
Digital twin can exist in all of the ship's life cycle, not only whenperception before the data collection, at the same time also includes theentity originally design processing, construction test and operationmaintenance of the data and the corresponding digital model, theformation of the overall information flow, convenient and large data
forecasting and all kinds of model reuse, Physical assets can bemonitored in real time, assessed for safety, predicted for failure, anddigitally experimented with, ultimately driving and optimizing the realworld.

KEY WORDS: digital twin; proper orthogonal decomposition; CFD;
reduced-order model

INTRODUCTION

Professor Tao Fei(2019) will traditional twin three-dimensional digitalmodel update to five dimensions, namely the twin data and services
added two new dimensions, at the same time, the aircraft, power plants,ships, and other areas of the top ten specific reference scheme is put
forward, make the digital technology of twin motivated effect can fall to
the ground as soon as possible in the related field, facing the whole life
cycle of ships he proposed control method, It mainly includes fourWith the rapid development of high and new technology, the newtechnology fields began to combine with the traditional manufacturingindustry, setting off the fourth industrial revolution. Its main purpose isto use information technology to realize the transformation of majorindustries and enter the era of intelligence, so digital twin technology,

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