Marine Technology - October 2008 - Page#44

<BODY> <span id="lblContents">? T), and highly loaded (1.25 ? T) conditions, allowing the effects of beam to draught ratio to be investigated. The raw data (vm, RTm) were represented by a spline curve that is tangent to the axis of speed at the origin. Later, an analysis of the smooth test data obtained from the spline curve was performed by using Hughes' method (Aydin 2002). The equations used in this procedure are given as follows (Salci 1985): CTm = CVm + CWm CVm = 1 + km CFm CFm = 0.075 log Rnm - 2 0.075 log Rns - 2 2 2 (3) (4) (5) (6) (7) (8) (9) (10) (11) ITTC - 57 Fns = Fnm = Fn CFs = Fig. 6 The appendages on the model 148/1C ITTC - 57 ks = km = k CVs = 1 + k CFs CWs = CWm = CW CTs = CVs + CW 4/25, respectively, and their relevant characteristics are given in Table 3. The models 148/3B(C) and 148/4B(C) of the fishing boats 148/3 and 148/4 were built with the cruiser stern to investigate the effects of the stern geometry on the resistance characteristics. Additionally, the effects of the chine shape on the form factor and the wave-making resistance coefficient were examined by rounding the chine of the model 148/1B. The tests of the models 148/3B and 148/4B were executed in trimmed conditions both by stern and by bow, to investigate the effect of trim on the form factor and the wave-making resistance coefficient. To reveal the influence of the appendages on the form factor and the total resistance coefficient, the tests of the models 148/1A, 148/1B, and 148/1C were repeated with the appendages such as the rudder, the heel of the rudder and the stern tube present (see Fig. 6). All the tests were carried out in the lightship (0.75 ? T), loaded (1.00 The form factor for the model, km (in equations 4 and 8) was determined with both modified Hughes' method and Prohaska's method for comparison. In the calculations, however, the form factors appointed by modified Hughes' method were taken into consideration. The resistance characteristics for all the fishing boats were obtained for the ideal conditions. In other words, they are the values that are calculated by assuming perfectly smooth and clean underwater hull form, in the absence of waves and currents in the sea, without any wind and without any air resistance. The wake measurement tests of the geosim models 148/1B and 148/1C of the parent fishing boat were carried out by Kempf circles method. As a result of these tests, it was found that the nominal wake coefficient varied between 0.22 and Fig. 7 The variation of wave-making resistance coefficient with Froude number, in the loaded condition OCTOBER 2008 MARINE TECHNOLOGY 199</span> <br /> <br /> <a href="http://www.digitalwavepublishing.com/" title="Digital Magazine">Digital Wave Publishing</a> </BODY>