Last modified: 2015-05-22
Abstract
Tank test is often conducted in order to estimate ship propulsion performance or the effect of energy saving device. Since tank test involves a lot of apparatus and instruments, it becomes so complicated and cannot avoid the error occurrence in measured data. Therefore, it is important to assess the error and its propagation. Uncertainty analysis is useful because it provides not only a measure of the quality of the data but also what is dominated as error source.
Recently ship performance in actual seas is focused as well as that in calm seas. International Maritime Organization (IMO) discussed the evaluation method of ship performance in actual seas and developed guidelines for the calculation of the coefficient fw for decrease in ship speed in a representative sea condition. The guidelines recommends that on the process of calculating fw added resistance in short waves obtained in tank test should be used. Added resistance in short waves is required to be measured with accuracy.
This paper reports the application of uncertainty analysis for measurement of added resistance in short waves. Uncertainty analysis is carried out with the results of multiple tests in still water and short waves, and uncertainty of added resistance due to short waves is assessed.