Rapid estimation of near-and far-field wave wake from ships and application to hull-form design and optimization

A method is presented by which the wave wake generated by a ship may be repeatedly calculated very rapidly. The method is based on linear thin-ship theory, using the idea of elemental tent functions as building blocks to represent the hull, which have previously been applied in the context of resistance minimization. This approach allows much of the calculation to be carried out in advance, with the results stored in a database. Issues of convergence, accuracy, and storage strategy are discussed. In order to demonstrate the application of the approach to preliminary design optimization, an illustrative study is carried out in which hull forms for monohull and catamaran vessels are optimized in the sense of minimizing the maximal wave height along a series of longitudinal cuts. The effect of the transverse location of the cuts on the resulting hull forms is found to be quite substantial, especially for the catamarans; the performance of the vessels optimized to reduce wave height at one transverse location may be quite suboptimal at another location, illustrating the difficulty of choosing an appropriate specification for low-wash vessels.