The Optimization Design Of Bulbous Bow For A Container Vessel

The resistance performance of hull is consisted of wave-making resistance and viscous resistance components. The probability of reducing the viscous resistance is generally little for given speed. While the wave-making resistance is very sensitivity to the changing of the lines of hull and the shape of bulbous bow in some range of Froude number, it is important to modify the form of bulbous bow and the hull for getting little wave-making resistance, especially for the container vessel with the Froude number more than 0.2.After a general introduction of the development of CFD, it is shown the basic theory of CFD computation in the paper and the characteristic of wave-field for wave-making. Also it is used the method of CFD for optimization design of bulbous bow-lines for a container vessel in the paper. The ahead extendable length of bulbous bow, the height of bulbous bow above the baseline and the transverse area of the bulbous bow at perpendicular are all used as the parameters of the representation of bulbous bow. The computation shown the range of optimized geometric parameters of bulbous bow and form for the minimum energy and the relation of the coefficient of wave-making and the three parameters of bulbous bow which are given above.The proposal of this investigation is the optimization design of bulbous bow-lines for a container vessel. The results of wave-making coefficients and relative data of wave-making field both from computation based on RANS approach and Michell integral method are provided for 7 different designs of bulbous bow lines respectively in this paper. According to the minimum energy from the sample of average wave-making energy for each design of bulbous bow-lines, which is to be objective function in this computation, the geometric parameters for optimization lines of bulbous bow can be determined. The resistance components and the wave-field for wave-making for ship hull by using CFD method have been validated based on corresponding model test results. Therefore, the optimized bulbous bow-lines can be used in the ship design practice.