Q1. A ship model of length 5 m has a wetted surface area of 4.2 m2 and is tested in water of density 1000 kg/m3. The test give the valve of residuary resistance for a range of model speed as shown in table Q5.
(a) (i) plot a curve of residuary resistance against speed for the model.
(ii) Comment on the shape of this curve.
(b) for a geometrically similar ship of length 125 m operating in sea water of density 1025 kg/m3 at service speed of 16.0 knots, the following data is applicable;
Appendage allowance = 7%
Weather allowance = 14%
Quasi-propulsive coefficient (QPC) = 0.7
Transmission losses = 3%
Determine the shaft power required for the ship at its service speed.
Note; The friction co efficient for the ship in sea water is 1.42 with speed in ms and index (n) for ship and model is 1.825.
Please buy a membership plan and login via our app to view answers.
Download our App
