对国外转塔式光电瞄准吊舱进行了划代,介绍了典型第三代吊舱的主要技术特点,定义了衡量光电吊舱集成度的四个评价标准:通光孔径与舱体直径之比、通光孔径的立方与系统重量之比,舱体直径的立方与系统重量之比以及有效载荷重量与系统重量...对国外转塔式光电瞄准吊舱进行了划代,介绍了典型第三代吊舱的主要技术特点,定义了衡量光电吊舱集成度的四个评价标准:通光孔径与舱体直径之比、通光孔径的立方与系统重量之比,舱体直径的立方与系统重量之比以及有效载荷重量与系统重量之比,实现了从宏观层级对性能相近的光电瞄准吊舱功能密度或技术水平的定量评价。介绍了国外典型装备的发展状况,重点针对美国MTS-B吊舱、土耳其ASELFLIR350吊舱及之后的400/500、加拿大MX-15D吊舱、法国EUROFLIR410吊舱和德国ARGOS II HDT等典型产品进行了对比分析,介绍了各自的技术风格、特点和重要载荷;通过正向设计评估验证了MTS-B前置望远系统的性能指标和ASELFLIR350的光学有效载荷;总结了现代光电瞄准吊舱的几大趋同化技术特点:多波段共孔径折反式主系统+旁轴小口径次系统的光机架构正取得共识、多种波段的激光探测技术日益倾向主动光学方向、基于多轴多框平台和快反镜相结合的复合轴控制技术正在普及、详查探测更注重目标细节区域增强、多波段图像融合信息处理技术在显控中越发重要。展开更多
Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs(Floating Production Storage and Offloading) suffer from the ...Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs(Floating Production Storage and Offloading) suffer from the environment loads, including the freak wave. The freak waves were generated based on the improved phase modulation model, and the coupling model of FPSO-SPM(Single Point Mooring) was established by considering internal-turret FPSO and its mooring system. The dynamic response characteristics of both FPSO and SPM affected by the freak wave were analyzed in the time domain. According to the results, the freak waves generated by original phase modulation model mainly affect the 2nd-order wave loads. However, the freak waves which are generated by random frequencies phase modulation model affect both 1st-order and 2nd-order wave loads on FPSO. What is more, compared with the irregular waves, the dynamic responses of mooring system are larger in the freak waves, but its amplitude lags behind the peak of the freak wave.展开更多
The load and corrosion caused by the harsh marine environment lead to the severe degradation of offshore equipment and to their compromised security and reliability. In the quantitative risk analysis, the failure mode...The load and corrosion caused by the harsh marine environment lead to the severe degradation of offshore equipment and to their compromised security and reliability. In the quantitative risk analysis, the failure models are difficult to establish through traditional statistical methods. Hence, the calculation of the occurrence probability of small sample events is often met with great uncertainty. In this study, the Bayesian statistical method is implemented to analyze the oil and gas leakages of FPSO internal turret, which is a typical small sample risk but could lead to severe losses.According to the corresponding failure mechanism, two Bayesian statistical models using the Weibull distribution and logarithmic normal distribution as the population distribution are established, and the posterior distribution of the corresponding parameters is calculated. The optimal Bayesian statistical model is determined according to the Bayesian information criterion and Akaike criterion. On the basis of the determined optimal model, the corresponding reliability index is solved to provide basic data for the subsequent risk assessments of FPSO systems.展开更多
This paper presents a series of design curves to aid in the selection of turret mooring systems for tankers based Floating Production Storage and Offloading (FPSO) systems. These curves are appropriate to water depths...This paper presents a series of design curves to aid in the selection of turret mooring systems for tankers based Floating Production Storage and Offloading (FPSO) systems. These curves are appropriate to water depths ranging from 100 m to 600 m. The curves can be used as a preliminary design tool, allowing the designer to quickly evaluate alternative mooring system configurations, including the number of mooring lines, the characteristics of chain and wire rope to be deployed and the. initial tension. With a knowledge of the total environmental force and vessel motion characteristics, the designer can determine the appropriate system for closer evaluation.展开更多
To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluatio...To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluation, the optimal structure of the turret for single-point mooring systems has been determined. Through model tests of a turret mooring system, several groups of data such as forces, moments and displacements under different environmental conditions have been obtained. Stresses and strains of the turret structure have been calculated by means of the finite element method corresponding to the situation in the model experiment. The study shows that the selected turret structure and the designed turret assembly are technically feasible.展开更多
The longitudinal strength of turret mooring productive/storage tanker is studied. A numerical example has been implemented according to the method presented in this paper to give practical illustration. From the resul...The longitudinal strength of turret mooring productive/storage tanker is studied. A numerical example has been implemented according to the method presented in this paper to give practical illustration. From the results of the numerical example, it is concluded that the turret hole located near the forward of the amidships has small effect on the longitudinal strength of the ship hull. As for design extreme value of wave bending moment of storage tanker, statistic method is a more reasonable methodology, especially with the consideration of the servere environmental conditions. The primary estimation of design section modulus of turret storage tanker can be determined by this design bending moment.展开更多
In this paper, the second-order perturbation method in frequency domain is used to calculate RAO and spectra of motion and mooring line tension of a turret-moored tanker in ballast condition. The calculated results ar...In this paper, the second-order perturbation method in frequency domain is used to calculate RAO and spectra of motion and mooring line tension of a turret-moored tanker in ballast condition. The calculated results are compared with corresponding experiment results. In the experiment the wave heading is 180 degrees, and the wave spectra is the P-M spectrum and white noise spectrum. In the theoretical calculations, the damping coefficient of slow oscillation of the tanker is determined on the basis of the damping obtained from a test of irregular waves where the mooring system is replaced by a nonlinear spring with nonlinear stiffness similar to that of the mooring system. From the comparison between theoretical calculations and experiment al results, it can be found that the theoretical results obtained by the second-order perturbation method in frequency domain are in good agreement with the experimental results, indicating that the damping coefficient of slow oscillation of the tanker required in frequency domain calculation can be determined by reference to the damping coefficient of the tanker moored by a spring system in irregular waves, and the second-order perturbation method can be used to analyze the dynamic response of a turret-moored tanker.展开更多
文摘对国外转塔式光电瞄准吊舱进行了划代,介绍了典型第三代吊舱的主要技术特点,定义了衡量光电吊舱集成度的四个评价标准:通光孔径与舱体直径之比、通光孔径的立方与系统重量之比,舱体直径的立方与系统重量之比以及有效载荷重量与系统重量之比,实现了从宏观层级对性能相近的光电瞄准吊舱功能密度或技术水平的定量评价。介绍了国外典型装备的发展状况,重点针对美国MTS-B吊舱、土耳其ASELFLIR350吊舱及之后的400/500、加拿大MX-15D吊舱、法国EUROFLIR410吊舱和德国ARGOS II HDT等典型产品进行了对比分析,介绍了各自的技术风格、特点和重要载荷;通过正向设计评估验证了MTS-B前置望远系统的性能指标和ASELFLIR350的光学有效载荷;总结了现代光电瞄准吊舱的几大趋同化技术特点:多波段共孔径折反式主系统+旁轴小口径次系统的光机架构正取得共识、多种波段的激光探测技术日益倾向主动光学方向、基于多轴多框平台和快反镜相结合的复合轴控制技术正在普及、详查探测更注重目标细节区域增强、多波段图像融合信息处理技术在显控中越发重要。
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51279130 and 51479134)
文摘Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs(Floating Production Storage and Offloading) suffer from the environment loads, including the freak wave. The freak waves were generated based on the improved phase modulation model, and the coupling model of FPSO-SPM(Single Point Mooring) was established by considering internal-turret FPSO and its mooring system. The dynamic response characteristics of both FPSO and SPM affected by the freak wave were analyzed in the time domain. According to the results, the freak waves generated by original phase modulation model mainly affect the 2nd-order wave loads. However, the freak waves which are generated by random frequencies phase modulation model affect both 1st-order and 2nd-order wave loads on FPSO. What is more, compared with the irregular waves, the dynamic responses of mooring system are larger in the freak waves, but its amplitude lags behind the peak of the freak wave.
基金financially supported by the National International Science and Technology Cooperation Specific Projectthe Development of Risk Assessment Software for Floating Offshore Wind Turbine(Grant No.2013DFE73060)the Development of Failure Database and Risk Assessment System for FPSO(Grant No.G014614002)
文摘The load and corrosion caused by the harsh marine environment lead to the severe degradation of offshore equipment and to their compromised security and reliability. In the quantitative risk analysis, the failure models are difficult to establish through traditional statistical methods. Hence, the calculation of the occurrence probability of small sample events is often met with great uncertainty. In this study, the Bayesian statistical method is implemented to analyze the oil and gas leakages of FPSO internal turret, which is a typical small sample risk but could lead to severe losses.According to the corresponding failure mechanism, two Bayesian statistical models using the Weibull distribution and logarithmic normal distribution as the population distribution are established, and the posterior distribution of the corresponding parameters is calculated. The optimal Bayesian statistical model is determined according to the Bayesian information criterion and Akaike criterion. On the basis of the determined optimal model, the corresponding reliability index is solved to provide basic data for the subsequent risk assessments of FPSO systems.
文摘This paper presents a series of design curves to aid in the selection of turret mooring systems for tankers based Floating Production Storage and Offloading (FPSO) systems. These curves are appropriate to water depths ranging from 100 m to 600 m. The curves can be used as a preliminary design tool, allowing the designer to quickly evaluate alternative mooring system configurations, including the number of mooring lines, the characteristics of chain and wire rope to be deployed and the. initial tension. With a knowledge of the total environmental force and vessel motion characteristics, the designer can determine the appropriate system for closer evaluation.
基金Project sponseored by special scientific research foundation for doctoral subjects
文摘To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluation, the optimal structure of the turret for single-point mooring systems has been determined. Through model tests of a turret mooring system, several groups of data such as forces, moments and displacements under different environmental conditions have been obtained. Stresses and strains of the turret structure have been calculated by means of the finite element method corresponding to the situation in the model experiment. The study shows that the selected turret structure and the designed turret assembly are technically feasible.
文摘The longitudinal strength of turret mooring productive/storage tanker is studied. A numerical example has been implemented according to the method presented in this paper to give practical illustration. From the results of the numerical example, it is concluded that the turret hole located near the forward of the amidships has small effect on the longitudinal strength of the ship hull. As for design extreme value of wave bending moment of storage tanker, statistic method is a more reasonable methodology, especially with the consideration of the servere environmental conditions. The primary estimation of design section modulus of turret storage tanker can be determined by this design bending moment.
基金National Natural Science Foundation of China(Grant No.59709002)
文摘In this paper, the second-order perturbation method in frequency domain is used to calculate RAO and spectra of motion and mooring line tension of a turret-moored tanker in ballast condition. The calculated results are compared with corresponding experiment results. In the experiment the wave heading is 180 degrees, and the wave spectra is the P-M spectrum and white noise spectrum. In the theoretical calculations, the damping coefficient of slow oscillation of the tanker is determined on the basis of the damping obtained from a test of irregular waves where the mooring system is replaced by a nonlinear spring with nonlinear stiffness similar to that of the mooring system. From the comparison between theoretical calculations and experiment al results, it can be found that the theoretical results obtained by the second-order perturbation method in frequency domain are in good agreement with the experimental results, indicating that the damping coefficient of slow oscillation of the tanker required in frequency domain calculation can be determined by reference to the damping coefficient of the tanker moored by a spring system in irregular waves, and the second-order perturbation method can be used to analyze the dynamic response of a turret-moored tanker.