A Data Replenishment Method for Self Regulating Sail-Assisted Ships Considering Big Data
The concept of intelligent sail-assisted ships based on big data comes to people's mind gradually. Data loss and distortion cannot be avoided during data collecting and preprocessing process. In this paper, a data replenishment method based on computational fluid dynamics (CFD) method is proposed and simulation cases are done to explain the method
Steady sailing performance of a hybrid-sail assisted bulk carrier
The steady sailing performance of a sail-assisted bulk carrier is investigated utilising towing-tank derived hydrodynamic derivatives and wind tunnel measured aerodynamic properties of the sails and the ship. The aerodynamic characteristics investigated include the ship hull at the fully-loaded draught, the sail–sail interaction effects for two sets of four identical hybrid-sails, and the sail–hull interaction effects for the same two sets of identical sails in the presence of the selected bulk carrier hull-form. This is in addition to lift–drag measurements of single isolated sails of each shape. The form of the two sets of soft sails was rectangular and triangular. This paper is concerned with assessing the benefits of a sail-assisted ship operation, and hence a steady-state rather than complete time-domain integrations of the governing equations are reported. The results of the completed analysis suggest that the benefits of the derived sail generated driving force are greater than the overhead of equipping the ship with a selected system of hybrid-sails. Sail-assisted ships could represent an important contribution to an improving global environment by reducing the demands for a driving force through the propeller.
ON THE MANOEUVRING PERFORMANCE OF A SHIP WITH THE PARAMETER OF LOADING CONDITION
When predicting ship manoeuvring performance at the initial design stage, it is considered that the loading condition is one of the important parameters for manoeuvring characteristics. To accurately predict ship manoeuvrability, hydrodynamic forces acting on a ship in any loading condition must be estimated. In this paper, approximate formulae for estimating the hydrodynamic forces acting on ships in any loading conditions such as half loaded, ballast and trim by stern conditions are proposed. These approximate formulae were derived from the results of a model test. Thirteen models were used to obtain the hydrodynamic forces consisting of general cargo, car carrier and RORO ships. The model test was carried out on 13 ships for fully loaded condition, on 11 ships for ballast condition and 5 ships for half loaded condition. The predicted results agreed well with the model test results. Therefore, this method will be useful for practical prediction of manoeuvrability for conventional ships at the initial design stage. However since the approximate formulae were investigated on ship models there still remain some problems to be solved such as a correlation, scale effect and so on, to predict the manoeuvring performance of a full scale ship.