The authors previously introduced a semi-empirical formula that enabled fast estimation of the added resistance of ships in head waves, and in this study the formula is further refined for easy use in engineering appl...The authors previously introduced a semi-empirical formula that enabled fast estimation of the added resistance of ships in head waves, and in this study the formula is further refined for easy use in engineering applications. It includes an alternative ship draft correction coefficient, which better accounts for the wave pressure decay with ship’s draft. In addition, it only uses the speed and main characteristics of the ship and wave environment as input, and has been simplified to the extent that it can be readily processed using a pocket calculator. Extensive validations are conducted for different ship types at low to moderate speeds in various typical irregular sea conditions, and encouraging results are obtained. This relevant and topical research lies within the framework of the recent IMO MEPC.232（65） （2013） EEDI guidelines for estimating the minimum powering of ships in adverse weather conditions, which specify for the use of simple methods in current Level 2 assessment within engineering applications.Keywords： added resistance, minimum power, IMO regulation, EEDI regulation, weather coefficient, semi-empirical formulas, ships, head waves展开更多
Three-dimensional(3-D)power prediction method from model test has been widely accepted and used for many years.Form factor k is the most important characteristics of 3・D method and very crucial to the accurate power p...Three-dimensional(3-D)power prediction method from model test has been widely accepted and used for many years.Form factor k is the most important characteristics of 3・D method and very crucial to the accurate power prediction.However,it's rather difficult to get the accurate value of k for those ships with pronounced bulbous or large transom from model test.In this paper,a new method to predict power is proposed,using k from CFD while other data from model test(or experimental fluid dynamics(EFD)).Delivered power prediction using the combination of CFD/EFD method agrees well with sea-trial results.展开更多
基金Partly Supported by the Collaborative Project SHOPERA under Grant Agreement No.605221
文摘The authors previously introduced a semi-empirical formula that enabled fast estimation of the added resistance of ships in head waves, and in this study the formula is further refined for easy use in engineering applications. It includes an alternative ship draft correction coefficient, which better accounts for the wave pressure decay with ship’s draft. In addition, it only uses the speed and main characteristics of the ship and wave environment as input, and has been simplified to the extent that it can be readily processed using a pocket calculator. Extensive validations are conducted for different ship types at low to moderate speeds in various typical irregular sea conditions, and encouraging results are obtained. This relevant and topical research lies within the framework of the recent IMO MEPC.232（65） （2013） EEDI guidelines for estimating the minimum powering of ships in adverse weather conditions, which specify for the use of simple methods in current Level 2 assessment within engineering applications.Keywords： added resistance, minimum power, IMO regulation, EEDI regulation, weather coefficient, semi-empirical formulas, ships, head waves
文摘Three-dimensional(3-D)power prediction method from model test has been widely accepted and used for many years.Form factor k is the most important characteristics of 3・D method and very crucial to the accurate power prediction.However,it's rather difficult to get the accurate value of k for those ships with pronounced bulbous or large transom from model test.In this paper,a new method to predict power is proposed,using k from CFD while other data from model test(or experimental fluid dynamics(EFD)).Delivered power prediction using the combination of CFD/EFD method agrees well with sea-trial results.
