Based on historical wind fields in the Bohai Sea, a sequence of annual extremal wave heights is produced with numerical wave models for deep-water and shallow water. The design wave heights with different return perio...Based on historical wind fields in the Bohai Sea, a sequence of annual extremal wave heights is produced with numerical wave models for deep-water and shallow water. The design wave heights with different return periods for the nearest deep-water point and for the shallow water point are estimated on the basis of P-III type, Weibull distribution, and Gumbel distribution; and the corresponding values for the shallow water point are also estimated based on the HISWA model with the input of design wave heights for the nearest deep-water point. Comparisons between design wave heights for the shallow water point estimated on the basis of both distribution functions are HISWA model show that the results from different distribution functions scatter considerably, and influenced strongly by return periods; however, the results from the HISWA model are convergent, that is, the influence of the design wave heights estimated with different distribution functions for deep water is weakened, and the estimated values decrease for long return periods and increase for short return periods. Therefore, the numerical wave model gives a more stable result in shallow water design wave estimation because of the consideration of the effect of physical processes which occur in shallow water.展开更多
Return period is generally adopted to calculate the design value of environmental condition in offshore structure design. However, it can not make relevant adjustment according to structure＇s, especially the mobile u...Return period is generally adopted to calculate the design value of environmental condition in offshore structure design. However, it can not make relevant adjustment according to structure＇s, especially the mobile unit＇s, life time or its operation areas and usually make the design either insufficiently safe or rather uneconomical. A formula is developed to solve this problem in the case of the design wave height, where the risk, the design life, the distributions of wave heights in operation areas and the operating durations in each area are regarded as parameters. The applications of this method and the comparisons with the general method are presented. The result of this method is considered to be proper.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.49776282)
文摘Based on historical wind fields in the Bohai Sea, a sequence of annual extremal wave heights is produced with numerical wave models for deep-water and shallow water. The design wave heights with different return periods for the nearest deep-water point and for the shallow water point are estimated on the basis of P-III type, Weibull distribution, and Gumbel distribution; and the corresponding values for the shallow water point are also estimated based on the HISWA model with the input of design wave heights for the nearest deep-water point. Comparisons between design wave heights for the shallow water point estimated on the basis of both distribution functions are HISWA model show that the results from different distribution functions scatter considerably, and influenced strongly by return periods; however, the results from the HISWA model are convergent, that is, the influence of the design wave heights estimated with different distribution functions for deep water is weakened, and the estimated values decrease for long return periods and increase for short return periods. Therefore, the numerical wave model gives a more stable result in shallow water design wave estimation because of the consideration of the effect of physical processes which occur in shallow water.
基金the National Great Project of Scientific and Technical Supporting Programs Funded by Ministry of Science & Technology of China During the 11th Five-year Plan (No. 2006BAA01A25)
文摘Return period is generally adopted to calculate the design value of environmental condition in offshore structure design. However, it can not make relevant adjustment according to structure＇s, especially the mobile unit＇s, life time or its operation areas and usually make the design either insufficiently safe or rather uneconomical. A formula is developed to solve this problem in the case of the design wave height, where the risk, the design life, the distributions of wave heights in operation areas and the operating durations in each area are regarded as parameters. The applications of this method and the comparisons with the general method are presented. The result of this method is considered to be proper.
