An Analysis on the General Concept Design Technology

of the U.S. Naval Ship

 

WANG Hao¹，PEI Da-ming¹，GAN Lin²，HAO Wei-wei¹，CHEN Rong-zhi³，CHEN Yi-kun⁴

（1. China Institute of Marine Technology & Economics, Beijing 100081, China;

2. Wuhan Secondary Ship Design Institute, Wuhan 430063, China;

3. Singapore Technologies Marine Ltd. (ST Marine), Singapore 999002, Singapore;

4. Guangzhou Shipyard International Co., Ltd., Guangzhou 511462, China)

 

Abstract: This paper analyzes the development trend of U.S. naval ship concept design technology developed in recent years and points out three typical features in the development process, i.e. model-based ship system engineering has become the basis of concept design; multi-disciplinary cooperation has become the trend of naval ship concept design; and system oriented integration has become the object of naval ship concept design. Based on these features, this paper shows some examples in the engineering practices and gives comments on the difficult points of the major technology of naval ship concept design.

Key words:concept design technology of naval ship; model-based system engineering; multi-disciplinary cooperation

 

 

 

Prediction and Measurement Analysis on the Stern Hull Sinkage of a CON-RO Vessel in Erection Stage

 

WAN Zhong，WANG Jia-ying，YANG Li-zhi

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

 

Abstract: Taking a CON-RO vessel as the research objective, the stern hull sinkage deformation in erection stage is analyzed and predicted with the finite element calculations and the measurement on site. The result of the comparison between calculation and measurement shows that the finite element calculation can simulate the stern hull deformation trend in longitudinal and vertical directions with good accuracy, but there is discrepancy in the transversal direction. The factors behind the discrepancies are analyzed. The finite element calculation method would provide technical reference for the prediction of stern hull sinkage deformation of similar ship products.

Key words:CON-RO vessel; stern hull sinkage deformation; finite element analysis

 

 

 

Study on Marine Airbag Explosion Model

and Damage Based on Energy Method

 

ZHAO Dian-hua，DUAN Qing-ling

(Shandong Nanhai Airbag Engineering Co., Ltd., Jinan 250101, China)

 

Abstract: A calculation model is established to solve the explosion problem of marine airbag during ship landing and launching. It divides the explosion energy into two sorts - the energy stored internally and the deformation energy due to the deformation of air sac. Based on the TNT equivalent model, the overpressure of shockwave is calculated according to “virtual distance” to evaluate the harmfulness of the explosion from two aspects, i.e., the overpressure characteristics of the shock wave and the explosion damage type of the sac. Thus adverse explosion damages can be avoided by improving the sac structure, and the safe space of explosion could be defined. This study provides an analysis method for the design calculation and an evaluation for safe construction of marine airbags.

Key words:marine airbag; explosion; compressed gas; virtual distance; TNT model

 

 

 

Research on the Seakeeping Model Test of a 13000dwt

Open-Top Multi-Purpose Vessel

 

HE Xin-yu，YANG Bo，CHEN Xiao-min

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

 

Abstract: This paper studies the seakeeping model test for the first 13000dwt hatchcoverless multi-purpose vessel designed and constructed by a Chinese institute for the unlimited navigation areas. The seakeeping model test is to determine the minimum freeboard, which includes the determination of model parameters, green water measurement in cargo tanks, assessment on the effectiveness of freeing ports and the analysis of the model test results, along with the suggestions for the improvement of subsequent designs. The result shows that the hatch coaming of certain height can significantly reduce green water onboard and the theoretical formulae cannot determine quantity, dimensions and positions of freeing ports, instead it is more effective to rely on the model test. This study provides references for the design of same ship types.

Key words:hatchcoverless; multi-purpose vessel; model test; seakeeping; green water; freeing port

 

 

 

Research on the Temperature Field of SPB Type LNG Carrier

 

MA Chen-zeng^1,2，TANG Wen-yong^1,2

(1. State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;

2. Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240, China)

 

Abstract: This paper studies the temperature field of SPB type LNG (Liquefied Natural Gas，LNG) carrier though the unique structural design different from the membrane design makes it difficult to do so. Problems such as the thermal convection effect of special components, the division of inner hull thermal convection space and the calculation method of convective heat transfer coefficient are analyzed and properly treated during the establishment of the hull heat transfer model. The finite element model is established based on the powerful finite element software MSC.Nastran and MSC.Patran, and the hull temperature field is solved by a calculation program written with the control language PCL.

Key words:LNG carrier; SPB type liquid tank; convective heat transfer coefficient; convection space; structure temperature field

 

 

 

Design Optimization of Helicopter Deck Structure

 

MA Zhen-miao，ZHU Bo-hua，ZHANG Jin-bao，ZHOU Jun，YU Yang

(Jiangnan Shipyard (Group) Co., Ltd., Shanghai 201913, China)

 

Abstract: Structure design optimization is an effective way to control the overall weight of living quarter, reduce construction cost and shorten construction cycle. Based on the analysis of the structure characteristics and force characteristics of the helicopter deck on offshore platform, the original design of H shape steel truss for the helicopter deck in the living quarter of jack-up platform is changed into T shape plate structures, and the finite element analysis according to BV rules is performed with MSC.Patran/Nastran. The result shows that the adoption of T shape plate structure can reduce the weight of helicopter deck structure on the premise of meeting same strength requirements, decrease welding work, save construction cost, and shorten the construction cycle.

Key words:helicopter deck; plate structure; T shape structure; design optimization

 

 

 

 

Analysis on Ship Noise Measurement Under DP Condition

 

CHU Nian-sheng，LIAN Zhao-hua

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

 

Abstract: According to the regulations of MSC 337 (91) for ships with Dynamical Positioning (DP) system, the noise level of the thrusters should be measured when the thruster loading is ≥40% at the time the ship is going to stationary. As there isn’t specific rule requirement on the sea trial ship state, this study carries out noise measurements of an onboard clinic room under several ship states during sea trial based on the power configuration and general arrangement of a DP offshore support vessel. The results are analyzed to find the acceptable ship states of better effectiveness. The actual working status of each thruster under DP condition are recorded, where the possibility of noise measurement under DP mode is excluded. Meanwhile, suggestions on the sea trial are delivered to the shipyard on the premise of meeting regulatory requirements, which can provide effective guidance for the shipyard to carry out sea trials, and it is expected that relevant guidelines would be issued by the authorities..

Key words:DP condition; noise measurement; analysis

 

 

 

 

Sound Insulation Calculation and Design of Composite

Structure Based on MSC.337(91)

 

PAN Liu-liu，LIU Kun，CHEN Hui-qin

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

 

Abstract: According to Code on Noise Level on Board Ships MSC.33(91), this study adopts the statistical energy method to simulate the actual measurement system of sound insulation index, and compares the simulated result with actual measurement, so as to propose a reliable sound insulation index calculation method for the sound insulation calculation and design of composite wall panels and decks.

Key words:ship noise; sound insulation index calculation; composite wall panel; sound insulation design; statistical energy method; MSC.337(91)

 

 

 

General Design of Seismic Source Vessel

 

LIU Xue-qin¹，JIANG Hong-tao²，ZHANG Hai-bin¹

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

2. China Oilfield Services Limited, Tianjin 300451, China)

 

Abstract: This paper introduces three kinds of seismic vessels according to the difference in operation modes. Of which, the emphasis is laid on the seismic source vessel. The characteristics, main technical specifications, general arrangement of the vessel are specified. Then the design of Hai Yang Shi You 751 is taken as an example to explain the key design points such as the consideration of rules and regulations in design, design of safety zone, selection of propulsion form, towing capacity and underwater noise requirement based on the ship’s characteristics and main design requirements.

Key words:seismic source vessel; general design; safety zone; underwater noise

 

 

 

Application of NAPA STEEL to the Development

and Design of Luxury Cruiser

 

SHEN Tong-wei，YANG Xiao-rui，XU Xu-min，FAN Xiang-dong

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

 

Abstract: In order to seize the mature and effective procedures and methods for the development and design of luxury cruiser to accomplish the structural design work in a precise and efficiency way and to guarantee the safety and comfortability of the ship, this paper introduces the experience gained by Shanghai Merchant Ship Design & Research Institute from the development and design of a 70000GT cruise ship using NAPA STEEL, which covers the general concept of integrated 3D structural design, structural modeling and data output, as well as the conversion from geometry model to finite element model. The advantage of integrated 3D structural design is analyzed when compared with traditional design methods. At the same time, the insufficiencies existed are pointed out and suggestions to improve the work in the future are put forward.

Key words:luxury cruiser; NAPA STEEL; integrated 3D structural design; FEM model conversion

 

 

 

Study on Moonpool Hydrodynamics and

Its Effect upon Ship Motions

 

ZOU Kang，GUI Man-hai，LUO Liang

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

 

Abstract: This paper studies the moonpool hydrodynamics and its effect on ship motions through the model test of a deepwater multi-purpose subsea construction vessel. The result shows that the moonpool has a good ability to keep out the outside waves. It has only limited the effect on the ship motions but the wave elevations inside the moonpool are clearly reduced when compared with those outside the ship. Moreover, the response spectrum of wave elevation inside the moonpool has an obvious double-peak feature, and the self-oscillation of the moonpool influences significantly on the wave elevation inside. The level of the self-oscillation influence is studied quantitatively from the energy point of view. The result is useful for the quantitative analysis of the moonpool oscillation characteristics and could provide references for the design of this type of moonpools.

Key words:moonpool; hydrodynamic characteristic; ship motion; model test

 

 

On the Light Running Margin of Marine Propellers

 

WU Xiao-ping

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

 

Abstract: When the power of main engine drops and the Light Running Margin (LRM) of propeller remains unchanged there will be a problem that leads to insufficient propulsion power in rough seas. This paper introduces the propeller LRM, discusses the influence of LRM on relevant ship performances such as the power margin in rough seas, maneuverability and quick passage of barred speed range. The effects of Energy Saving Devices (ESD) on LRM are also discussed in the paper.

Key words:propeller; LRM; matching of propeller and engine

 

 

 

Design and Application of Centralized Motor Management

System on Ships

 

WANG Fu-li，GUO Li-feng

(1. Shanghai Jiao Tong University, Shanghai 200030, China;

2. China Ship Development and Design Center, Shanghai 201108, China)

 

Abstract: A centralized motor management system is designed for the ship motor monitoring equipment based on CAN bus technology. This paper introduces the composition, the functions and the characteristics of the system in order to provide a distinctive method for the conventional ship platform management system.

Key words:ship; motor; CAN; centralized management system

 

 

 

Test and Analysis of Ductile-Brittle Transition Temperature for AH32 Marine Steel Plate

 

CHEN Jing-hua，ZHAO Hua，WU Ze-nan，ZHANG Chun-e

(Zhoushan Institute of Calibration and Testing for Quality and Technology Supervision, Zhoushan 316021, China)

 

Abstract: This paper studies the relationship between the temperature and impact energy and the section fiber ratio of AH32 marine steel plates in different sizes, and uses the Boltzmann function fitting method to analyze the ductile-brittle transition temperature of AH32 marine steel plate in different thicknesses. The result shows that the obtained fitting curves of ductile-brittle transition temperature are different from each other. Thicker sample plates have higher transition temperature. Meanwhile, the initiation fractures of different sample sizes are analyzed with the scanning electron microscope. It also shows that thicker samples have higher temperature to cause brittle fracture. This indicates that the actual ductile-brittle transition temperature of the hull is higher than that of the standard test, so it is not safe to apply the data from standard test to hull design and to practice.

Key words:marine steel plate; ductile-brittle transition temperature; Boltzmann function; fracture analysis

 

 

 

The Technology of FPSO Single Point Mooring

Upper Wire Replacement

 

FU Fang-chao，GAO Yuan，GAO Chao，YANG Sheng

（COOEC Subsea Technology Co., Ltd., Shenzhen 518067, China）

 

Abstract: Under the situation that the production of the Floating Production Storage and Offloading (FPSO) is not interrupted and the position of FPSO is confined by 3 tugs, the demolition and discard of the old upper wire and the installation of a new upper wire could be carried out on the basis that the current forces acting on the FPSO is simply analyzed and a proper positioning scheme is worked out. This paper explains in detail the application of the method for the project, and shows that the technique can realize the replacement of the upper wire in single point mooring state without interrupting of the FPSO and suspending of the oil field during the replacement.

Key words:floating production storage and offloading; single point mooring; upper wire; diving support vessel; non-stop production

 

 

 

Analysis of ISO 15016-2015 and its Effect

on the Speed-test in Sea Trial

 

YU Xin，CHEN Sheng-lan，CAI Yue-sheng

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

 

Abstract: This paper introduces the background, the basic contents and the calculation method of ISO 15016-2015 and gives some advices to the speed test of the sea trial. The influence of different environmental factors on the speed correction calculation is analyzed based on result of the sea trial speed tests and the speed correction calculations of three 82000dwt bulk carriers. The conclusion shows that wave, temperature and wind are the main environmental factors influencing the results of speed/power analysis of the three ships under specific environmental conditions.

Key words:ISO 15016-2015; 82000dwt series bulk carriers; speed-test of sea trial; environmental factor