Dept. of Applied Mathematics
The University of Adelaide
South Australia 5005
Australia
22 December 1996
SUMMARY
A displacement vessel of a given loaded weight has a theoretical optimum length, usually somewhat longer than the conventional, which minimises its total calm-water drag. Some simple examples are given to illustrate this property. Genetic algorithm techniques are then used to find optimum dimensions for monohull and multihull vessels over a wide range of speeds and displacements, with a fixed assumption about the waterline, cross-section, and buttock shapes. Michell's integral is used for the wave resistance, the 1957 ITTC line for the skin friction, and a simple empirical formula for the form drag.
1. INTRODUCTION
2. BASIC CONSIDERATIONS
3. PREDICTION OF OPTIMAL PARAMETERS
4. RESULTS
5. CONCLUSION
6. REFERENCES
7. SYMBOLS