Flat Bottom Effects on Wave-Making Resistance

Abstract

The objective of this paper is to afford a more rational procedure for finding an optimum singularity distribution which will generate a practical ship form with a flat bottom as well as low wave-making resistance. The effects of singularity generated flat bottom on wave pattern are discussed both theoretically and experimentally. Measurements are made of wave pattern and total resistance of two Pienoids. One of them has a flat bottom, while the other has a curved keel line. The difference in the wave patterns measured of the models indicates a remarkable discrepancy between the liner theory and the experiments of the surface disturbances due to the singularities for flattening bottom. An optimum source distribution is then modified with consideration of this discrepancy. The modified singularity distribution is found to give a ship form with lower wave-making resistance than the un-modified.