Calculation of Leg Penetration Depth for

Jack-up Offshore Wind Turbine Installation Platform

 

WANG Hui-hua

（Jiangsu Longyuan Zhenhua Marine Engineering Co., Ltd., Nantong 226014, China）

 

Abstract: Considering the fact that majority of offshore wind turbines are installed by jack-up platforms, studies are carried out on the calculation method of platform leg mud penetration depth to ensure the safety of jack-up wind turbine installation platform. Then the method for calculation of the ultimate bearing capacity of multi-layered soil at sea bottom is proposed, taking into account the influence of the surrounding soil layers. The accuracy of the method is validated through the comparison between construction data and finite element result. The method provides reference for the installation operation of offshore wind turbines.

Key words:jack-up offshore wind turbine installation platform; leg penetration depth; multi-layered soil; punch-through

 

 

 

CFD Based Numerical Simulation of Ship-Propeller Flow Interaction

 

CHEN Ke¹，LAI Ming-yan²

（1. COSCO Shipping Development Co., Ltd., Shanghai 200135, China;

2. Shanghai Merchant Ship Design & Research Institute, Shanghai 201203, China）

 

Abstract: Numerical simulations based on Computational Fluid Dynamics (CFD) are performed to study the ship-propeller flow interaction. Calm water resistance and self-propulsion calculations are conducted to the international ship benchmark KCS, and the effect of propeller suction on hull surface pressure distribution and hull resistance is analyzed. The numerical accuracy of two propeller treatment methods - Moving Reference Frame (MRF) method and sliding mesh method - is compared. The result shows that the thrust and torque obtained by the two methods are close to each other, but the hull resistance is over-predicted by the MRF method, and there is a big error in the calculation of the self-propulsion factor, while the self-propulsion factor obtained by the sliding mesh method agrees well with the experimental result.

Key words:ship-propeller interaction; CFD; MRF method; sliding mesh method

 

 

 

Fire Fighting System Design for the Diving Equipment Area of Saturated Dive Support Vessel

 

WANG Xian-li ¹，KANG Jian²，LIU Zhi-chao³

（1. Marine Design & Research Institute of China, Shanghai 200011, China；

2. Shanghai Zhenhua Heavy Industries Company Limited, Shanghai 200125, China;

3. Shanghai Zhenhua Heavy Industries Qidong Marine Engineering Company Limited, Qidong 226259, China）

 

Abstract: This paper discusses the system design process and main equipment selection calculation for the diving equipment area of saturated Dive Support Vessel (DSV) based on the study of the fixed fire-fighting system for this ship type, which provides reference for the design, calculation and logic control of the system.

Key words:Saturated Dive Support Vessel; spray system; water mist system; interlock release control

 

 

Numerical Study on Flapping Foil Based on Overset Method

 

LI Yong-cheng, XU Ling-ling, ZHAO Qiao-sheng, ZHANG An-tong, WANG Xi-jian

（State Key Laboratory of Hydrodynamics, China Ship Scientific Research Center Shanghai Branch, Wuxi 214082, China）

 

Abstract: In this study, numerical simulations of the flapping foil are conducted based on the overset method and a systematic analysis is performed to investigate the effect of flapping foil’s motion parameters on the propulsive efficiency, such as the phase lag between heaving and pitching, the pitching amplitude and the Strouhal number. The optimum motion parameters are determined on the basis of self-defined propulsive efficiency and the vortex structure of the rear part of the flapping foil. The overset method can provide reference for the solution of other moving boundary problems.

Key words:flapping foil; overset grid; propulsive characteristics; numerical simulation

 

 

 

Cylinder-Shaped FPSO Structural Design and

Lightweight Optimization

 

ZHOU Jia, ZHAO Xi-bing, WANG Pu

（Marine Design & Research Institute of China, Shanghai200011, China）

 

Abstract: Design method and key points are obtained through calculations and analysis on the concept design of a cylinder-shaped Floating Production, Storage and Offloading (FPSO) unit. The conclusion that the design control load is the component’s design pressure has been reached based on the analysis and comparison of different design conditions. Besides, the result of global finite analysis on the cylinder-shaped FPSO shows that the connecting area between the damping plate and the hull outer shell has relatively high stress, which requires special attention. Several arrangement and subdivision design schemes are compared according to the structural analysis result, so as to obtain the global lightweight optimization to provide reference for offshore engineering designers.

Key words:FPSO; structural design; lightweight

 

 

 

Fatigue Strength Assessment for Ultra Large Container Ship Based on Spectral Analysis

 

GAO Qian，ZHAO Xin

（Shanghai Waigaoqiao Shipbuilding Co., Ltd., Shanghai 200137, China）

 

Abstract: Fatigue failure is one of the major failures of ships and offshore engineering structures, of which the fatigue problem is especially severe for large ships built with high-tension steel. This study discusses the basic principles of fatigue spectral analysis method based on FDA 3 fatigue calculation and assessment of Lloyd’s Register (LR), and provides a combined method for the calculation of wave frequency and cumulative fatigue damage. Moreover, the fatigue strength analysis and assessment for the major structures of an ultra large container ship are performed on this basis.

Key words:ultra large container ship; fatigue strength; spectral analysis method

 

 

 

Deck Load and Structural Analysis of a Semi-Submersible Barge

 

WANG Zheng^1,2，CUI Xiao-min²

（1. Shanghai Jiao Tong University，Shanghai 200240, China;

2. CCCC Third Harbor Engineering Co., Ltd., Shanghai 200032, China）

 

Abstract: Semi-submersible barge is a kind of special engineering vessel which is mainly used for the transportation and submergence/floating of large concrete caisson or steel structures so analysis of the deck load and structures is of crucial importance for its deck design. A 6000t semi-submersible barge for special equipment transportation is taken as the research object to analyze the deck load and structures. To meet the demand of adding special equipment carriage on the original carriage of large caisson structures, two deck load conditions are calculated and analyzed, thus to optimize the deck structure in order to reduce construction cost and increase efficiency.

Key words:semi-submersible barge;deck load;longitudinal;force model

 

 

 

A Research on Optimized Type Selection of Main Engine

for the Green 400000t VLOC

 

XUE Jia

（Nantong CIMC Sinopacific Offshore & Engineering Co., Ltd., Qidong 226251, China）

 

Abstract:Based on the comparison of the parameters of OEM produced engines, the most suitable engine is selected according to the requirements for speed and fuel consumption. The waste heat utilization of the engine is calculated, and the emission control equipment for NO_x and SO_x are studied and recommended. The result of the research would contribute to the higher ship efficiency and lower emission, which has a significant effect on the improvement of Energy Efficiency Design Index (EEDI).

Key words:400000t VLOC; main engine; design optimization

 

 

 

Development and Test Verificationof EGR Blower Prototype for Marine Diesel Engines

 

JINYu-shan, LIXiang, ZHANGDong-ming

（Shanghai Marine Diesel Engine Research Institute,Shanghai 201108, China）

 

Abstract: This paper introduces the Exhaust Gas Recirculation (EGR) technology ofmarine diesel engines with emphasis on the function of the key EGR component - the blower. It is the first time for EGR blowersto be developed on low-speed two-stroke marine diesel engine6EX340EF, rated power 5520kW,in China. This paper elaborates the majorresearchonthe first generation EGR blower prototype produced byShanghai Marine Diesel Engine Research Institute (SMERI) , including technical studies, mode analysis and harmonic response analysis of the main components. Verification for the platform performance test of EGR blower is also discussed, the result shows that both the power and torque of the EGR blower prototype can meet the requirements of mass flow and compression ratio, andhigh operation efficiencyis realized(efficiency of motor working point≥90%,efficiency of compressor working point≥60%).

Key words:marine diesel engine; EGR blower; platform test;emissioncontrol

 

 

 

Stress Analysis of Propeller Hydraulic Nut

 

TU Xing-xing, XU Yong-jie, ZHU Kun

（Shanghai Merchant Ship Design and Research Institute, Shanghai 201203, China）

 

Abstract: Themodel of propeller hydraulic nut is created with ABAQUS and its stress distribution is obtained with finite element calculation. Then the influence of dimensional parameters on the maximum stress of the nut is analyzed. The fillet radius of the piston cavity r, the ratio between outer diameter and inner diameter D₂/D₁ and the ratio between length and inner diameter L/D₁ have the most significant influence on the maximum stress, but the rule of influence is quite simple. The chamfer length T of the nut has almost no influence on the maximum stress and the influence of the other 3 parameters (d/q，p/q and h) has the same pattern: when they increase, the maximum stress decreases before increases.

Key words:finite element analysis; hydraulic nut; stress distribution

 

 

 

Summary on the Advantages of Tilted Azimuth Thruster for Drilling Platform

 

CHENG Wei-jun, JIANG Ai-guo, ZHU Zheng-yu, ZHANG Lei

（China Oilfield Services Limited, Yanjiao 065201, China）

 

Abstract: The hydraulic interference among azimuth thruster, hull and downstream propellers, as well as the issue of thruster forbidden zone, will all limit the maximum performance of the azimuth thruster. Based on the 8°tilted azimuth thruster recently released by Wärtsilä, the hydraulic interference to the hull bottom, pontoon and downstream propellers is analyzed and compared with the right angle azimuth thrusters. The result shows that the 8°tilted azimuth thruster has the unique advantages in eliminating the interference to hull bottom and downstream propellers, which has a wider application prospect and more engineering advantages.

Key words:azimuth thruster; dynamic positioning; hydraulic interference; 8°tilt angle

 

 

 

Research Into a Method for Restoring Lines of Ancient Ships

 

WEI Bin, MA Juan

（Wuxi traffic branch, Jiangsu Union Technical Institute, Wuxi 214151, China）

 

Abstract: Restoration of ancient ships is usually based on restoring of ship’s outer contour. It is difficult to realize in case there is not a physical reference. Taking Wuxi Xizhang Boat as the research object, attempt has been made in adopting the computer-aided method to restore the hull lines according to the pithy formula of the shipbuilding workers and the relevant historical references. Performance calculations of the restored lines are conducted. Through the comparison of parameters such as the block coefficient and the deadweight, the reliability of the restored lines is preliminarily validated, which paves the way for the subsequent general arrangement and structural restoration.

Key words:hull lines restoration; Xizhang Boat; computer-aided method

 

 

 

Difficulties and Countermeasures for the Application of LR Rules for Naval Ships on a Naval Vessel

 

ZHAO Ji-quan

（Hudong-Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China）

 

Abstract: Rules and Regulations for the Classification of Naval Ships published by Lloyd’s Register (abbreviated LR NSR) is generally the preferred choice of international target users. LR NSR is very different from the merchant ship rules in terms of the Concept of Safety, the Concept of Operations, and the mechanisms to deal with non-compliances. This paper introduces the rules and basic requirements of LR NSR concerning naval ship classification, certificate list and regulation tailoring, and put forward the solutions and countermeasures for its application on a naval vessel for the first time. Taking into account the actual construction of the vessel, the differences and application difficulties of the LR NSR compared with conventional rules for naval ships are listed and analyzed from seven aspects including fire zone division, subdivision and stability, ammunition cabin safety, structural strength, air-conditioning system balance duct design, thermal insulation material for ducts and flexible ducts fitted in outlet and inlet of fan, as well as emergency lighting, then proper countermeasures are proposed.

Key words:LR Rules for Naval Ships; military trade; SOLAS

 

 

 

Study on the Rollover Risk Assessment and

Safety Rectification Measures of a Sightseeing Bamboo Raft

 

ZHANG Xiao-ying, HU Zhe, LIN Guo-zhen, LUO Chun-lian

（School of Marine Engineering, Jimei University, 

Key Laboratory of Ships and Ocean Engineering of Fujian Province, Xiamen, 361021, China）

 

Abstract: Bamboo raft is a traditional transportation tool in China, which is now still widely used in tourism. Different from steel ships, the special natural affinity and embodied cultural elements of the bamboo raft make it quite popular in between the scenic spots of inland waters. Though it is widely used, its examination method and safety measures are lagging behind, there is not any authoritative safety standards or guidance available, which often leads to accidents and brings huge potential hazard to the tourists on water. Hence, the reports of bamboo rafts related accidents in the recent years are collected, and the bamboo raft rollover risk of a scenic area is evaluated to give correspondent rectification measures.

 

 

 

A Study on the Leakage Accident of

Membrane Type LNG Carriers

 

GAO Jian-feng^1.2，YUAN Jian-wei¹，XU Wen-xiang¹，QIU Yun-qin¹

（1. School of Petrochemical and Energy Engineering, Zhejiang Ocean University, Zhoushan 306022, China；

2. State and Local Joint Engineering Laboratory in Harbor Areas of Oil and Natural Gas Storage and

Transportation Technology, Zhoushan 306022, China)

 

Abstract: Based on the investigation and analysis of LNG (Liquefied Natural Gas) leakage accidents occurred on LNG carriers around the world in recent years, this paper summarizes the factors that lead to the leakage accidents. The structure of membrane type LNG carrier is analyzed and an accident tree is established with 'the leakage of membrane type LNG carrier' as the top event. Through systematic analysis of 38 selected events, the minimal cut sets of the accident tree are obtained based on the principle of accident tree analysis. The structural importance of each basic event on the leakage of LNG carrier during loading/uploading and transportation is summarized, and the role of each basic event is analyzed according to the minimal cut sets. This study provides protective measures for the operation safety of LNG carrier in order to avoid accident.

Key words:membrane type LNG carrier; leakage; accident tree; basic event; minimum cut sets