To makesystem-of-systems combat simulation models easy to be developed and reused, simulation model formal specification and representation are researched. According to the view of system-of-systems combat simulation,...To makesystem-of-systems combat simulation models easy to be developed and reused, simulation model formal specification and representation are researched. According to the view of system-of-systems combat simulation, and based on DEVS, the simulation model＇s fundamental formalisms are explored. It includes entity model, system-of-systems model and experiment model. It also presents rigorous formal specification. XML data exchange standard is combined to design the XML based language, SCSL, to support simulation model representation. The corresponding relationship between SCSL and simulation model formalism is discussed and the syntax and semantics of elements in SCSL are detailed. Based on simulation model formal specification, the abstract simulation algorithm is given and SCSL virtual machine, which is capable of automatically interpreting and executing simulation model represented by SCSL, is designed. Finally an application case is presented, which can show the validation of the theory and verification of SCSL.展开更多
Laboratory tests have been conducted on the basis of theoretical analysis of stability of armour Grate Plates with reference to 20 structures. Some empirical formulas of statility thickness of Grate Plates have been o...Laboratory tests have been conducted on the basis of theoretical analysis of stability of armour Grate Plates with reference to 20 structures. Some empirical formulas of statility thickness of Grate Plates have been obtained in consideration of the effects of water depth in front of the structures and critical wave period. The test results have been compared with field data.展开更多
A Modified Hybrid Element Method (MHEM) for computing wave loads on arbitrary geometric bodies is presented in this paper. The additional unknowns in Mei's method are eradicated. Water depth varies in space. The M...A Modified Hybrid Element Method (MHEM) for computing wave loads on arbitrary geometric bodies is presented in this paper. The additional unknowns in Mei's method are eradicated. Water depth varies in space. The MHEM adopts simple functionals to simplify the numerical scheme and the ICCG method to save CPU and storage; thus computing wave loads for a large flow domain or short waves can be carried out on small-sized computers or even microcomputers. Numerical results are compared with analytical solutions and experimental data. Good agreement is observed.展开更多
Interaction between current and underwater bottom topography modulates roughness of the sea surface, which in turn yields variation of the radar scattering echo. By using the mechanism, this paper presents a simulatio...Interaction between current and underwater bottom topography modulates roughness of the sea surface, which in turn yields variation of the radar scattering echo. By using the mechanism, this paper presents a simulation model for Synthetic Aperture Radar (SAR) imaging of underwater bottom topography. The numerical simulations experiments were made using the Princeton Ocean Model (POM) and analytical expression theory of SAR Image in Mischief sea area. It is concluded that the SAR image is better visual when water depth of underwater bottom topography is shallow or gradient of underwater bottom topography is high.展开更多
Based on a 3-D dynamic numerical model of primitive equation, the general circulation in the East China Sea and the Yellow Sea was studied with a 0.25 ° ×0.25 ° horizontal grid and a realistic bottom to...Based on a 3-D dynamic numerical model of primitive equation, the general circulation in the East China Sea and the Yellow Sea was studied with a 0.25 ° ×0.25 ° horizontal grid and a realistic bottom topography. The tidal current and Kuroshio (Japan current) were considered. The main results of the general circulation in the East China Sea and the Yellow Sea were obtained. The numerical results were compared with the observed results. The compared results show that 3-D dynamic numerical model is efficient to predict general circulation in the East China Sea and the Yellow Sea.展开更多
In order to extract the internal tidal current from the current data which is not measured from the sea surface to the bottom, a data processing method is developed. It is based on the fact that the internal wave curr...In order to extract the internal tidal current from the current data which is not measured from the sea surface to the bottom, a data processing method is developed. It is based on the fact that the internal wave currents above and below the sharp thermocline are inverse in direction. This method is a practical extension to that proposed by Shu (1985) that can be only used to quite ideal current data. The ADCP data collected on the South China Sea is then processed by this method. The internal tidal current is successfully extracted.展开更多
Making use of altimeter wind data and standard sounding data in a mesoscale numerical model of PSU/NCAR (MM5), we test four-dimensional data assimilation scheme based on nudging. The purpose of this paper is to determ...Making use of altimeter wind data and standard sounding data in a mesoscale numerical model of PSU/NCAR (MM5), we test four-dimensional data assimilation scheme based on nudging. The purpose of this paper is to determine what meteorological fields and what assimilation method have positive effect on typhoon sea surface wind by simulating two typhoon cases in MM5. We perform seven experiments for 9608 Typhoon (Case 1): one control experiment, three analysis nudging experiments, two observation nudging experiments and one analysis and observation nudging experiment; we perform one control experiment and one analysis nudging experiment for 9711 Typhoon (Case 2). The results show assimilating wind-thermal fields can effectively improve simulation accuracy of the model; the experiment combining standard sounding data and surface observations can improve greatly the simulation accuracy of the model; the altimeter data contain lots of sea surface information and also have positive impact on typhoon sea surface wind.展开更多
文摘To makesystem-of-systems combat simulation models easy to be developed and reused, simulation model formal specification and representation are researched. According to the view of system-of-systems combat simulation, and based on DEVS, the simulation model＇s fundamental formalisms are explored. It includes entity model, system-of-systems model and experiment model. It also presents rigorous formal specification. XML data exchange standard is combined to design the XML based language, SCSL, to support simulation model representation. The corresponding relationship between SCSL and simulation model formalism is discussed and the syntax and semantics of elements in SCSL are detailed. Based on simulation model formal specification, the abstract simulation algorithm is given and SCSL virtual machine, which is capable of automatically interpreting and executing simulation model represented by SCSL, is designed. Finally an application case is presented, which can show the validation of the theory and verification of SCSL.
文摘Laboratory tests have been conducted on the basis of theoretical analysis of stability of armour Grate Plates with reference to 20 structures. Some empirical formulas of statility thickness of Grate Plates have been obtained in consideration of the effects of water depth in front of the structures and critical wave period. The test results have been compared with field data.
文摘A Modified Hybrid Element Method (MHEM) for computing wave loads on arbitrary geometric bodies is presented in this paper. The additional unknowns in Mei's method are eradicated. Water depth varies in space. The MHEM adopts simple functionals to simplify the numerical scheme and the ICCG method to save CPU and storage; thus computing wave loads for a large flow domain or short waves can be carried out on small-sized computers or even microcomputers. Numerical results are compared with analytical solutions and experimental data. Good agreement is observed.
文摘Interaction between current and underwater bottom topography modulates roughness of the sea surface, which in turn yields variation of the radar scattering echo. By using the mechanism, this paper presents a simulation model for Synthetic Aperture Radar (SAR) imaging of underwater bottom topography. The numerical simulations experiments were made using the Princeton Ocean Model (POM) and analytical expression theory of SAR Image in Mischief sea area. It is concluded that the SAR image is better visual when water depth of underwater bottom topography is shallow or gradient of underwater bottom topography is high.
文摘Based on a 3-D dynamic numerical model of primitive equation, the general circulation in the East China Sea and the Yellow Sea was studied with a 0.25 ° ×0.25 ° horizontal grid and a realistic bottom topography. The tidal current and Kuroshio (Japan current) were considered. The main results of the general circulation in the East China Sea and the Yellow Sea were obtained. The numerical results were compared with the observed results. The compared results show that 3-D dynamic numerical model is efficient to predict general circulation in the East China Sea and the Yellow Sea.
文摘In order to extract the internal tidal current from the current data which is not measured from the sea surface to the bottom, a data processing method is developed. It is based on the fact that the internal wave currents above and below the sharp thermocline are inverse in direction. This method is a practical extension to that proposed by Shu (1985) that can be only used to quite ideal current data. The ADCP data collected on the South China Sea is then processed by this method. The internal tidal current is successfully extracted.
文摘Making use of altimeter wind data and standard sounding data in a mesoscale numerical model of PSU/NCAR (MM5), we test four-dimensional data assimilation scheme based on nudging. The purpose of this paper is to determine what meteorological fields and what assimilation method have positive effect on typhoon sea surface wind by simulating two typhoon cases in MM5. We perform seven experiments for 9608 Typhoon (Case 1): one control experiment, three analysis nudging experiments, two observation nudging experiments and one analysis and observation nudging experiment; we perform one control experiment and one analysis nudging experiment for 9711 Typhoon (Case 2). The results show assimilating wind-thermal fields can effectively improve simulation accuracy of the model; the experiment combining standard sounding data and surface observations can improve greatly the simulation accuracy of the model; the altimeter data contain lots of sea surface information and also have positive impact on typhoon sea surface wind.
