Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering ConferenceShanghai, 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

The Influence of Pontoon Cross-section Shape on the Wave Run-upof the Semi-submersible Platform

Daifei Wang 1, Gang Xu 1,2, Guichao Niu 1
School of Naval Architecture and Ocean Engineering, Jiangsu University of Science and Technology, Zhenjiang, China
2Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China1ABSTRACT

column type to platform movement and air gap. Tang Wenxian etal.(2017) used the hydrodynamic analysis software AQWA to study thehydrodynamic performance of the semi-submersible platform with two
different column structures and obtained the mechanism of column
structure's effect on the hydrodynamic performance of the semisubmersible platform. Wang Zhidong et al. (2019) studied the influenceof column cross section shape on wave run-up of semi-submersible
platform column based on viscous flow software Fine/Marine. Theresults show that the column shape structure has an obvious influenceon the wave run-up around it.

This paper chooses four typical pontoons cross-sectional shapes: square,rounded, semi-circular, and wedge-shaped, and the length of thepontoons are selected to ensure that the drainage volume of the
pontoons keeps constant, and the depth of the pontoon does not change.
Numerical results of wave run-up have been compared with different
pontoon shapes, and the influence of different pontoon shapes on thewave surface distribution between columns has been presented. The
results show that the dimensionless value of wave run-up on theplatform columns with different pontoon shapes decreases while theposition is far away from the column gradually. Comparing wave runup of different shapes of pontoons, we found that the wave run-up of
wedge-shaped pontoon has the smallest value and the wave run-up ofsquare pontoon has the largest value.

In this paper, based on a mother-type offshore satellite launch platform,
the motion performance of different pontoon shapes of launchplatforms is studied by using commercial software STAR-CCM+, andthe wave run-up characteristics of different pontoon shapes areemphatically analyzed. In the process of numerical simulation,
combined with the Froude Scale, the typical wave steepness wasselected, the size and spacing of the column were kept unchanged, andonly the pontoon shapes of the platform were changed.

KEY WORDS: Semi-submersible platform; Pontoon shape; Run-up
1.

Introduction

2.

The exploitation of Marine resources has gradually entered the field of
the deep sea, and countries worldwide are vigorously promoting thelaunch of maritime satellites. The launch platform at sea in the processof specific waters or sailing will inevitably suffer from a combinationof factors such as wind, wave and current, which can produce such asheave and sway motion, and the phenomenon of the wave run-up
frequently and significant. Whether the wave run-up phenomenon issignificant or not directly affects the impact loads of column or deck.
However, the violent irregular movement and slamming of the platform
will seriously affect the regular operation of the launch platform, theexpected launch of the rocket, the safety of personnel, and the regular
operation of various equipment. Therefore, to improve the movement
performance of the launch platform, the main body of the platformneeds to be built with a more suitable size and shape. Analysis of theplatform column wave run-up, air gap changes, and other issues,
discuss the impact of the main parameters of the platform on the motion
performance. It has become the focus of increasing attention of oceanengineering and aerospace scientists to select relevant parameters of theplatform.

Establish model and mesh of the domain

2.1 Model parameters and establishment of numerical tankThis paper uses a mother-type semi-submersible platform as a putative
launching platform for a satellite at sea. The platform consists of an
upper deck, four columns, two cylindrical cross braces, and twopontoons. The geometric parameters of the maritime satellite launchplatform are shown in Table 1.
Table 1. Geometric parameters of the semi-submersible platform
Parameter Namemagnitude
units
Molded length
58.0
mMolded breadth
40.0mDeck length
39.4m
Deck width
37.8
m
Body height
19.2m
Column height
10.9m
Column section
7.2*7.2m
Diameter of the cross brace
1.25m

Shen Pengfei(2013) kept the weight, center of gravity position,displacement, the moment of inertia, draft, and other major parametersof the semi-submersible platform constant and analyzed the response ofConsidering that the calculation amount of directly placing the actual

2097