Computer aided geometrical variation and fairing of ship hull forms

Abstract

Two distinct aspects of computer aided ship design are addressed in this thesis. First, a geometrical hull form modification technique employing the longitudinal repositioning of sections is developed. The second aspect deals with the mathematical representation of lines and line fairing. Before this is done however, justification is presented for utilizing third degree polynomials as an approximation to the spline curves of the naval architect. The results obtained indicate that a fairing procedure based on a least squares curve fitting criteria and a lines representation procedure based on parametric cubic equations could be adapted to generate faired hull forms from the roughest preliminary hull design. Additionally, the hull form modification technique could be programmed so as to produce designs with desired values of Cp, LCB, Cw and LCF from a basis design of similar type.