Application of CAE in Ship Performance Research

Application of CAE in the field of ship performance research Abstract: This paper discusses the importance of Computer Aided Engineering (CAE) technology and the feasibility of its application in the field of ship performance. From the aspects of principle, characteristics, function, composition, application effect and future development, this paper introduces the technical achievements and research projects independently innovated by China Shipbuilding Research Center in the field of CAE technology, including five major systems: ship type design system, hydrodynamic performance prediction system, digital pool test system, numerical pool simulation system and ship technical performance database. The above-mentioned systems are not only independent but also organically related to each other, and together constitute a comprehensive system for ship performance research

key words: ship and ship engineering; Ship form design; Hydrodynamic performance prediction; Digital pool test; Numerical pool simulation; Integrated system; Technical performance database

1 introduction

as China's traditional industry, shipbuilding industry is walking out of the dilemma of "sunset industry". On the one hand, it benefits from the support of the national macro industrial policy, on the other hand, it also benefits from the improvement and application of Computer Aided Engineering (CAE) technology. Ship CAE combines information technology with ship manufacturing to realize the informatization of ship product design, manufacturing, maintenance and management, so as to improve the research and development level and manufacturing capacity of the shipbuilding industry, accelerate the innovation of ship products and design technology, and accelerate the modernization process of ship development, production and management of shipbuilding enterprises. Improving the comprehensive ability and core competitiveness of shipbuilding industry is the main way and strategic measure to promote industrialization with informatization and realize the modernization of shipbuilding industry. For the shipbuilding industry, this development trend is not only an opportunity, but also a challenge, but also the only way for China to become a world shipbuilding power

the shipbuilding industry is characterized by large capital investment, long design and construction cycle and many professional categories involved. It is a comprehensive industry that must be coordinated by multiple enterprises and units. Under the current conditions, it is difficult to directly realize the whole process informatization of shipbuilding. We can first realize the informatization of one of the links, and then steadily promote it from point to area, in order to achieve the purpose of the whole process informatization of shipbuilding

in the process of ship manufacturing, ship form design and performance prediction are one of the main tasks of ship design, the key technologies in ship design, and the concentrated embodiment of the core competitiveness of ship products. CSSC has done a lot of fruitful and independent innovation work in the CAE field of ship form design and performance prediction. This paper briefly introduces some research achievements or ongoing CAE projects of CSSC with independent intellectual property rights

2 hull design system hds

the full name of hull design system HDS is hull design system. The system can carry out preliminary profile design according to user requirements, optimize the preliminary profile through the embedded CFD module, and carry out three-dimensional fairing for the design profile. Finally, the profile data is output in various file formats through the interface program, which can be directly used by the subsequent design software. The system is characterized by good human-computer interaction, convenient modification of ship form, and high data accuracy of smooth line, which meets the requirements of ship construction design

hds system is an open system, which is composed of main dimension estimation module, profile generation module, profile fairing module, ship type optimization 1, abnormal movement of indicator of spring fatigue test machine: module, ship type data interface module and ship type database, as shown in Figure 1

Figure 1 functional modules and business processes of HDS system

China Shipbuilding Research Center has completed the development of hds1.0 version. Hds1.0 includes the following modules:

(1) ship main dimension estimation module

the ship main dimension estimation module collects the main dimension, deadweight, speed and other parameters of more than 20000 advanced ships that have been built and classified, and takes the deadweight and speed as independent variables to regress the estimation formulas of main dimensions such as length, width, depth and draft of various ship types according to categories of oil tankers, bulk carriers, container ships, LPG ships, LNG ships and so on

(2) profile generation module

the profile generation module generates the hull line scheme according to the main dimensions obtained by the ship main dimension estimation module or the main dimensions input by the user. The user can select a similar ship type from the ship type database as the parent type, or directly input a type line as the parent type, and then obtain the preliminary design type line through the parent type transformation method. The user can also obtain the preliminary design profile through a series of interpolation methods

model line generation module can modify the ship form by using the parameter transformation method of the ship form, which can be used by the optimization design module. The parameter transformation method includes the local parameter transformation method and the whole ship parameter transformation method. The module provides the local parameter transformation method of spherical bow and stern frame. The whole ship parametric design technology will be provided in the subsequent version of HDS

(3) profile fairing module

the profile fairing module has the fairing function of the three-dimensional wireframe model of the ship shape line. It has the characteristics of perfect data structure, friendly man-machine interface, diverse interpolation functions and high fairing precision, and meets the requirements of the construction design of the ship shape line. The module has the functions of artificial fairing, semi-automatic fairing and full-automatic fairing, and can draw 3D rendering effect drawings and AutoCAD engineering drawings

(4) ship form optimization module

ship form optimization module is the application of CFD technology to optimize the ship form scheme. The optimization objective is the wave making resistance, and the CFD tool is the potential flow wave making calculation program. The series ship type scheme is generated by the preliminary design scheme of the ship type through the parameter transformation method of the ship type, and the automatic division of the potential flow calculation grid is preliminarily realized

(5) ship type data interface module

the ship type data interface module provides various output interfaces of the ship body line and can be connected with various design software, such as the input interfaces of the commercial CFD software shipflow3.0 and FLUENT6.0, and the input interfaces of the ship design software Napa, TRIBON and CADDS5

(6) ship type database

the ship type database provides the parent ship type line data for the line generation module and the parent ship performance data for the ship type optimization module

hds system takes ship form design as the main line, with simple operation and friendly interface, and provides users with a convenient and practical ship form design and development tool

3 hydrodynamic performance prediction system hps

the full name of hydrodynamic performance prediction system HPS is hydraulic performance prediction system. The system can predict, evaluate and optimize the navigation performance of large square coefficient low-speed ships (such as large and super large oil tankers, bulk carriers, etc.) and medium square coefficient medium high-speed ships (such as large and medium container ships, etc.), and can design the details of ship types and propellers that meet the preliminary design requirements of users according to the comprehensive requirements of rapidity, seakeeping and maneuverability. It is the first integrated design system for ship hydrodynamic performance in China with the characteristics of full function, high precision, wide application range, fast calculation speed and advanced technology

hps system is an open system, which is composed of application module, management module and database. The application modules of HPS system include main scale estimation module, rapidity estimation module (including propeller design), maneuverability estimation module, seakeeping estimation module, integrated hydrodynamic performance optimization module, etc. The management module includes system management, data management, image support and user interface management subsystems. The database includes performance database and working database. The performance database contains test data such as ship geometry and hydrodynamic performance, which can be accessed at any time when the system is running; The working database mainly stores the data generated during the operation of the system for users' reference and report printing. Figure 2 is the functional module and business process block diagram of HPS system

Figure 2 functional modules and business processes of the HPS system

hps system includes the following contents:

(1) concept design module

concept design module is one of the entrances to the HPS system. Its function is to provide the starting point for the next navigation performance optimization design (there can be three preliminary schemes) according to the technical and economic requirements put forward by the owner and in combination with the general layout, and give the "macro framework" of the required ship type

(2) ship form generation module

the ship form generation module generates the corresponding ship form line scheme according to the ship form macro framework and main parameters obtained from the conceptual design module. There are two generation methods: Series interpolation method and parent form transformation method

(3) comprehensive navigation performance prediction module

this module is the main calculation module of the integrated system, including 6 sub modules: hydrostatic performance calculation, resistance calculation, self navigation factor calculation, propeller design and propulsion performance calculation, seakeeping calculation and maneuverability calculation

(4) hydrodynamic performance evaluation and comprehensive optimization module

based on the excellent ship types in the performance database, an expert system for ship performance is established, and artificial intelligence or other methods are used to evaluate and optimize the comprehensive navigation performance of the designed ship type

(5) performance database

the quantity and quality of subsamples in the performance database is the most important connotation of the database, and is the foundation for the database to play its important role. The database collects the geometric data and corresponding model test data of about 300 modern ship types, including two model series developed by China Shipbuilding Research Center, namely, the large square coefficient low-speed ship model series and the medium square coefficient medium high-speed ship model series. The large square coefficient low-speed ship model series is composed of 15 ship models and 9 propeller models. The resistance test and self navigation test data form the digital atlas of the large square coefficient low-speed ship. The medium square coefficient medium high speed ship model series is composed of 9 ship models and 19 propeller models. The resistance test and self navigation test data form the digital map of medium square coefficient medium high speed ship

shids system has provided technical consultation for more than 100 ships of 10 units and has been used by 8 factories and design institutes. The practice shows that the integrated system is easy to operate, fast to calculate, and the calculation results reach the engineering practical accuracy. The SHIDS system has been introduced into the "oneortwo libraries" network platform and has become an application service of Shanghai "advanced manufacturing technology service platform"

4 digital water tank test system

the digital water tank test system is to transform the existing test system into a test process based on network and database, and realize the whole process and all-round digitization of customer requirements submission, test model processing, test instrument verification, signal acquisition and processing, data information warehousing and test report submission based on network

digital pool test system, such as 1% to 5%; Then the system includes customer communication digitalization, model processing digitalization, test process digitalization and test management digitalization, which are mainly reflected in the networking of data flow and information flow. The whole test process was completed in the network environment, and realized the organic combination with the database

since 2004, China Shipbuilding Research Center has started the construction of digital pool test system, and has made great progress. Figure 3 is a block diagram of the system

Figure 3 digital pool test system什么是功能性消化不良
绝经前爱出汗是怎么回事
心烦易怒失眠吃什么药好
勃起功能障碍