362 



HYDRODYNAMICS IN SHIP DESIGN 



Sec. 60.7 



Fig. 60. E Wake-Survey Diagram for TMB Model 



4358W-1, Representing a Variation of the Mariner 



Class Hull 



1953, Fig. 17, p. 176. This diagram is the same as in 

 Fig. 60.E. 



(e) U. S. Maritime Administration, Mariner design, 



"open water" or "clear water" stern, TMB model 

 4358W-3; SNAME, 1953, Fig. 16, p. 126. This 

 diagram is the same as in Fig. 60. G. 



(f) Wake-survey data for a model of the T-2 class tankers 



were published by N. H. Jasper and L. A. Rupp, 

 SNAME, 1952, Fig. 25a, p. 347. Four afterbody 

 sections at and adjacent to the stern are shown on 

 this diagram. 



60.7 Interpretation and Analysis of the TMB 

 Three-Dimensional Wake Diagram. The method 

 of plotting the projections of 3-diml incident- 

 velocity vectors at propulsion-device positions, 

 and of indicating the magnitude of the wake 

 fractions and the transverse velocity components, 

 is described in Sec. 11.6 and illustrated in the 



definition diagram of Fig. ll.E. Since it is most 

 important to an interpretation and analysis of 

 the 3-diml wake-survey diagram that the geo- 

 metric relationships be clearly understood, the 

 definition drawing is repeated here as Fig. 60.L. 

 The survey diagram is drawn on a sheet repre- 

 senting a transverse plane on the ship or model, 

 passing through the longitudinal center of the 

 propulsion device. For a model running at other 

 than zero trim, and for a screw propeller mounted 

 on a shaft having both declivity and convergence 

 (or divergence), this plane is very nearly normal 

 to the direction of motion. It is close enough to 

 the plane of the disc, in both position and direc- 

 tion, to serve all engineering purposes. The various 

 vectors drawn on this sheet represent simply the 

 projection upon it of the incident velocity vectors 



TMB Model 

 4358W-2 



Baseline 



210 deq 



Fig. 60.F Wake-Survey Diagram for TMB Model 



4358W-2, Representing a Variation of the Mariner 



Class Hull 



