Against the background of the current world facing an energy crisis,and human beings puzzled by the problems of environment and resources,developing clean energy sources becomes the inevitable choice to deal with a cl...Against the background of the current world facing an energy crisis,and human beings puzzled by the problems of environment and resources,developing clean energy sources becomes the inevitable choice to deal with a climate change and an energy shortage.A global ocean wave energy resource was reanalyzed by using ERA-40 wave reanalysis data 1957–2002 from European Centre for Medium-Range Weather Forecasts（ECMWF）.An effective significant wave height is defined in the development of wave energy resources（short as effective SWH）,and the total potential of wave energy is exploratively calculated.Synthetically considering a wave energy density,a wave energy level probability,the frequency of the effective SWH,the stability and long-term trend of wave energy density,a swell index and a wave energy storage,global ocean wave energy resources were reanalyzed and regionalized,providing reference to the development of wave energy resources such as wave power plant location,seawater desalination,heating,pumping.展开更多
Compliant offshore structures are used for oil exploitation in deep water. Tension leg platform (TLP) is a suitable type for very deep water. The nonlinear dynamic response of TLP under random sea wave load is necessa...Compliant offshore structures are used for oil exploitation in deep water. Tension leg platform (TLP) is a suitable type for very deep water. The nonlinear dynamic response of TLP under random sea wave load is necessary for determining the maximum deformations and stresses. Accurate and reliable responses are needed for optimum design and control of the structure. In this paper nonlinear dynamic analysis of TLP is carried out in both time and frequency domains. The time history of random wave is generated based on Pierson-Moskowitz spectrum and acts on the structure in arbitrary direction. The hydrodynamic forces are calculated using the modified Morison equation according to Airy’s linear wave theory. The power spectral densities (PSDs) of displacements, velocities and accelerations are calculated from nonlinear responses. The focus of the paper is on the comprehen-sive interpretation of the responses of the structure related to wave excitation and structural characteristics. As an example a case study is investigated and numerical results are discussed.展开更多
本文使用欧洲中期天气预报中心（European Center for Medium Range Weather Forecasting，ECMWF）近30年（1982-2011年）全球再分析资料（ECMWF 40 Year Re-analysis Interim）中的风场及海浪场资料，对全球海表10m风场、有效波高、平...本文使用欧洲中期天气预报中心（European Center for Medium Range Weather Forecasting，ECMWF）近30年（1982-2011年）全球再分析资料（ECMWF 40 Year Re-analysis Interim）中的风场及海浪场资料，对全球海表10m风场、有效波高、平均周期和平均波向进行了统计分析，并定义了一种计算季节变率的方法。研究发现，有效波高和平均周期均存在明显的季节变化，且北半球大洋比南半球大洋季节变化更为明显，印度季风区则例外。另外尝试用波龄揭示风浪、涌浪的分布特征，证实了全球海洋为涌浪占主导及太洋东部存在涌浪强化，同时发现了涌浪的分布在春夏季变化明显的特征。展开更多
Energy production based on fossil fuel reserves is largely responsible for carbon emissions, and hence global warming. The planet needs concerted action to reduce fossil fuel usage and to implement carbon mitigation m...Energy production based on fossil fuel reserves is largely responsible for carbon emissions, and hence global warming. The planet needs concerted action to reduce fossil fuel usage and to implement carbon mitigation measures. Ocean energy has huge potential, but there are major interdisciplinary problems to be overcome regarding technology, cost reduction, investment, environmental impact, governance, and so forth. This article briefly reviews ocean energy production from offshore wind, tidal stream, ocean current, tidal range, wave, thermal, salinity gradients, and biomass sources. Future areas of research and development are outlined that could make exploitation of the marine renewable energy （MRE） seascape a viable proposition; these areas include energy storage, advanced materials, robotics, and informatics. The article concludes with a sustainability perspective on the MRE seascape encompassing ethics, leg- islation, the regulatory environment, governance and consenting, economic, social, and environmental constraints. A new generation of engineers is needed with the ingenuity and spirit of adventure to meet the global challenge posed by MRE.展开更多
基金The National Basic Research Program of China under contract No.2012CB957803The Special fund for public welfare industry(Meteorology)under contract No.GYHY201306026
文摘Against the background of the current world facing an energy crisis,and human beings puzzled by the problems of environment and resources,developing clean energy sources becomes the inevitable choice to deal with a climate change and an energy shortage.A global ocean wave energy resource was reanalyzed by using ERA-40 wave reanalysis data 1957–2002 from European Centre for Medium-Range Weather Forecasts（ECMWF）.An effective significant wave height is defined in the development of wave energy resources（short as effective SWH）,and the total potential of wave energy is exploratively calculated.Synthetically considering a wave energy density,a wave energy level probability,the frequency of the effective SWH,the stability and long-term trend of wave energy density,a swell index and a wave energy storage,global ocean wave energy resources were reanalyzed and regionalized,providing reference to the development of wave energy resources such as wave power plant location,seawater desalination,heating,pumping.
文摘Compliant offshore structures are used for oil exploitation in deep water. Tension leg platform (TLP) is a suitable type for very deep water. The nonlinear dynamic response of TLP under random sea wave load is necessary for determining the maximum deformations and stresses. Accurate and reliable responses are needed for optimum design and control of the structure. In this paper nonlinear dynamic analysis of TLP is carried out in both time and frequency domains. The time history of random wave is generated based on Pierson-Moskowitz spectrum and acts on the structure in arbitrary direction. The hydrodynamic forces are calculated using the modified Morison equation according to Airy’s linear wave theory. The power spectral densities (PSDs) of displacements, velocities and accelerations are calculated from nonlinear responses. The focus of the paper is on the comprehen-sive interpretation of the responses of the structure related to wave excitation and structural characteristics. As an example a case study is investigated and numerical results are discussed.
文摘本文使用欧洲中期天气预报中心（European Center for Medium Range Weather Forecasting，ECMWF）近30年（1982-2011年）全球再分析资料（ECMWF 40 Year Re-analysis Interim）中的风场及海浪场资料，对全球海表10m风场、有效波高、平均周期和平均波向进行了统计分析，并定义了一种计算季节变率的方法。研究发现，有效波高和平均周期均存在明显的季节变化，且北半球大洋比南半球大洋季节变化更为明显，印度季风区则例外。另外尝试用波龄揭示风浪、涌浪的分布特征，证实了全球海洋为涌浪占主导及太洋东部存在涌浪强化，同时发现了涌浪的分布在春夏季变化明显的特征。
文摘Energy production based on fossil fuel reserves is largely responsible for carbon emissions, and hence global warming. The planet needs concerted action to reduce fossil fuel usage and to implement carbon mitigation measures. Ocean energy has huge potential, but there are major interdisciplinary problems to be overcome regarding technology, cost reduction, investment, environmental impact, governance, and so forth. This article briefly reviews ocean energy production from offshore wind, tidal stream, ocean current, tidal range, wave, thermal, salinity gradients, and biomass sources. Future areas of research and development are outlined that could make exploitation of the marine renewable energy （MRE） seascape a viable proposition; these areas include energy storage, advanced materials, robotics, and informatics. The article concludes with a sustainability perspective on the MRE seascape encompassing ethics, leg- islation, the regulatory environment, governance and consenting, economic, social, and environmental constraints. A new generation of engineers is needed with the ingenuity and spirit of adventure to meet the global challenge posed by MRE.
