A Consideration of Model-Ship Correlation on Wake Fraction : Disposition of Wake Data-2nd Report)

抄録

In the first report, wake data of large tankers in the fu11 load condition were put in order by a statistical method of analysis. Wake data in the ba11ast condition, however, were not mentioned in the first report as excessive scatter of the data appeared to need further studies. This paper deals with further analyses of whole wake data of the other less load conditions as well as the full load condition. The analyses are carried out in the same way as that of the first report. Five basic parameters representing the characteristics of the ship form and two additional parameters representing the features of the load condition are used as the basis of the analyses. The five basic parameters are the same as those finally adopted in the first report; their values in the full load conditions are used regardless of the load condition. The two additional parameters are &xdtri;'/&xdtri; and d_<A'>/d, where &xdtri; and d_<A'> are the displacement and draught at A. P. of a given load condition respectively. Final results are as follows. [numerical formula] [numerical formula] In the case of the fu11 load condition, the last two factors in each formula are equal to 1.0, and the formulae become just like those given for the fu11 load condition in the first report; afterwards, they have been improved in form. Consequently, the formulae can be genera11y app1ied to wake data of any load condition. For practical purposes, an approximate formula of the model-ship correlation factor was deve1oped in the first report; that is, [numerical formula] It has been confirmed in this report that this formula can be used as it is, though the basic formulae expressing (1-w) were modified.