42 



Figure 55 - Nondlmenslonal Plot of Characteristics 

 of TMB Displacement Float 



was ± 3 per cent and thus within the experimental error; this Justified draw- 

 ing the family of curves shown in Figure 35- 



The mode in which the resistance of the float changes is exhibited 

 very clearly in Figure 35- The positions of the humps are clearly defined, 

 and the rapid drop in drag coefficient as the float becomes submerged is 

 sharply emphasized. That all the spots fair into a single curve beyond a 

 speed-length ratio of about 6 indicates that the drag coefficient is very 

 nearly independent of load at sufficiently high speeds. However, the drag 

 coefficient for the parameter C^ = O.58 appears to rise above the curve at 



-^ = 8.3, so that this conclusion may be valid only as long as the float 

 yd 



remains at least slightly submerged. 



COMMENTS ON THE USE OF THE TMB DISPLACEMENT -FLOAT 

 DATA FOR DESIGN PURPOSES 



TMB displacement-float data as presented in Figure 35 provide de- 

 sign criteria for most ranges of load and speed that are likely to be en- 

 countered. However, the present data are not extensive enough to derive an 

 optimum float of this design for a given application, especially as regards 

 stability, at speed-length ratios greater than those covered by the experi- 

 ments described herein. Concerning the question of stability, it can be 

 assumed that stable designs will result for all C^ and -^ within the range 



