An interactive computer program for surface fairing has been developed using optimization technique and applied to ship hull form, which is represented by B-splines. The fairing is formulated as a standard optimization problem, where the change of control vertices of a specified surface zone is taken as design variables. The surface zones to be faired are obtained interactively by looking at the curvature contour drawing. The goal of the fairing is taken to minimize the maximum of curvatures, under certain constraints to be imposed by the user. These constraints are necessary to keep the original shape as much as possible by limiting the design variable change or by keeping the volume or area at a desired level. The sensitivity information necessary for design change is obtained by a direct numerical calculation. The formulation is tested first for curve fairing and then a ship hull form is used for illustration.
Comparing with the conventional method of fairing, where the user experience and intuition is of utmost importance, the present method is a unique and systematic method, although there still remains too much flexibility in the imposition of desirable constraints.
