An experimental investigation into the components of ship resistance

• Main Author: Cooke, Robert
• Other Authors: Kilner, F A
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2015
• Subjects: Civil Engineering
• Online Access: http://hdl.handle.net/11427/15823

Includes bibliography. === This thesis is an experimental investigation into the components of ship resistance. The traditional Froude method of scaling is investigated with reference to the measurement of skin friction and viscous pressure resistance. A literature review is given on the theoretical background and experimental measurement techniques. Two models are used for the experimental work, which sizes are in the geometric ratio of 2,7 to 1. The model form is half a body of revolution with a vertical sided superstructure. The block coefficient of the model is 0,621 and the length to beam ratio is 7. Two surface models and one reflex model are tested. One of the models has 40 pressure tappings located on its hull which are used to measure the total pressure resistance of the model. The components of resistance directly measured are total resistance, total viscous resistance and total pressure resistance. The resistance components inferred are skin friction resistance and wave-making resistance. The deduced skin friction is found to deviate from the Prandtl-von Karman skin friction formulation. The wave-making resistance agrees favourably with the predicted values using Mitchell's integral. The total viscous resistance increases sharply at Reynolds numbers greater than 3 x 10⁶.