878 



HYDRODYNAMICS IN SHIP DESIGN 



Sec. 78.15 



(2) Curves of effective power P b calculated for 

 the Taylor Standard Series model of identical 

 proportions, using the ATTC 1947 friction data, 

 with a ACp equal to that for the actual models, 

 and the reworked TSS data of M. Gertler (this 

 work is to be done by the Design Office). The 

 TSS curve is to cover the full-load condition only. 

 (These curves are not plotted but "angleworm" 

 curves giving the ratio (EHP/Taylor EHP) are 

 found in Figs. 78. Jc and 78. Kc on pages 882, 885). 



(3) Body plan showing hues of flow in entrance 

 and run, wave profile, location of separation 

 zones if determined, and other flow details. 

 (Reproductions of the transom-stern plan are 

 given in Figs. 52.U and 66.R). 



(4) Photographs of pertinent features of the flow 

 tests with tufts. (See Figs. 78.E and 78.F of Sec. 

 78.8). 



(5) Curves of sinkage of bow and stern, at the 

 FP and the AP, plotted as fractions of the length 

 L on a base of both T, (= V/VL) and F„ . 

 (These are plotted for the ABC transom-stern 

 hull in Fig. 58.B and for the arch-stern hull in 

 Fig. 58. C, for both the towed and the self-pro- 

 pulsion conditions. A discussion of the differences 

 is included in Sec. 58.2). 



(6) Transverse section at the propeller position 



(in the plane of the propeller disc), with wake 

 vectors and components indicated diagrammatic- 

 ally. (Fig. 60.M is adapted from the TMB dia- 

 gram) . 



(7) Curves of shaft power Pg (or propeller power 

 Pp), effective power Pe , rate of propeller rotation 

 n, ratio of Pe/Ps (or Pe/Pp), thrust-deduction 

 fraction t, wake fraction w, and real-slip ratio Sr , 

 for each model when driven by (1) the stock 

 propeller, and (2) the propeller of special design. 

 (These are reproduced in Fig. 78.1 for the arch- 

 stern model and in Fig. 78. Nc for the transom- 

 stern model, when driven by the stock propellers 

 only). 



(8) Open-water characteristic curves of jjo , Kr , 

 and IOKq , on a base of advance number J, for 

 the propeller of special design. (See Fig. 78. H for 

 TMB propeller 1986 and Fig. 78.Mc for TMB 

 propeller 2294. The propeller designed in Chap. 

 70 was not tested as a model). 



(9) Plot of successive positions of ship during a 

 270-deg turn at a specified speed (between 19.5 

 and 20 kt for the ship) and with a 35-deg rudder 

 angle. (This test was not carried out) . 



(10) Controllability in shallow water. (No test 

 was made on either ABC model) . 



(11) Plot of wavegoing-speed ratio on ratio of 



'0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.6 0.9 i.O I.I 1.2 



Advance Coefficient J- \^/(nD) 



Fig. 78. H Characteristic Curves of TMB Model Propeller 1986, Derived from Open- Water Tests 



