Investigation and improvement of Michell's thin-ship theory

Abstract

In this report, the Michell’s thin-ship theory which is a linear wave-making theory, is evaluated to investigate its accuracy in predicting the wave-making resistance stimulated by ships. The theory gives poor estimates for conventional hull forms at relative low speed range (Fn<0.30), specifically Wigley Hull and Series 60 Hull with CB = 0.6 which will be focused on in this report. This report introduces improvements to three components of the original theory, which are a) boundary layer, b) phase shifting and c) oscillations. The programming language, FORTRAN, is used to write a program that applies the original theory to calculate the wave resistance encountered by ships. The improvements are also included in the program to obtain the improved wave resistance values. The obtained wave-making resistance results based on the original and improved methods are compared thereafter to demonstrate the effectiveness of the introduced modifications.