Performance of Partially Submerged Propellers 



Table 2 

 Summary of Test Conditions 



PRESENTATION OF EXPERIMENTAL RESULTS 



The results of the experiments of the first phase are presented in Figs. 7-12 

 as propeller efficiency n, thrust coefficient K^, and torque coefficient Kg versus 

 advance coefficient j. The thrust and torque coefficients of all these propellers 

 show a characteristic increase, a maximum, and then a decrease as the advance 

 coefficient is decreased — similar to those of supercavitating propellers working 

 under cavitating conditions. Propeller 3820 in Figs. 9 and 10 also shows a defi- 

 nite discontinuity in the performance curves. This discontinuity will be discussed 

 in detail in a later section. 



The results of the second-phase experiments on Propeller 3768 are pre- 

 sented in Figs. 13- 15. The vertical e and horizontal e, locations of the cen- 

 ter of thrust from the shaft axis, expressed as a function of propeller diameter 

 are also included. In addition to the normal propeller coefficients, the horizontal 

 and vertical transverse force coefficients are included in Figs. 16- 18, which 

 are defined as follows: 



pn2D4 ' 



1459 



