Performance of Partially Submerged Propellers 



fully wetted or cavitating. More effective comparisons can be made by present- 

 ing hq and J as a function of the thrust coefficient 





T 



ip'2) A' V2 



where ^ is the submerged disk area, V is velocity, and T is thrust. Figures 

 19- 22 present the results of these comparisons. In Figs. 19 and 20 the results 

 of the partially submerged tests are compared with the supercavitating tests of 

 Propeller 3767 presented in Refs. [7j and [8j. Figure 23 shows the fully sub- 

 merged data of Propeller 3767 over a range of cavitation numbers which may 

 be compared to Fig. 21, showing the performance of the same propeller at 

 three partially submerged conditions. 



VISUAL OBSERVATIONS ;' • • 



Visual observation of the flow around Propeller 3768 indicates, at the high 

 J values prior to transition, that the spray is relatively low to the water surface 



.OU .00 .Oe .07 .06 0.1 .2 



THRUST COEFFICIENT, C/ 



.W .5 .fa .7 .£ 1.0 



Fig. 19 - C.^ - r^g - J diagram of propeller 4002 partially submerged 



1469 



