Figure 25 presents the Taylor wake fraction based on thrust 1-w,, and 
ae 
the Taylor wake fraction based on torque rele as derived from the measured 
values of ie and M, and the open-water characteristics of the propeller 
H H 
(Figure 11). These data indicate that (1-w,,) varies by only approximately 
3 percent during the simulated acceleration. The value of Cy varies 
by only 1 percent for simulated time t>40 seconds; however, the value of 
(1l-w,) varies substantially during the initial portion of the simulated 
Q 
acceleration (t<40 seconds). 
Figures 20 and 22 show that for all measured hydrodynamic and total 
loading components, except Fy which is small, the peak values, including 
H 
variation with blade angular position occurred at the self propulsion con- 
dition. That is, for the acceleration condition simulated (see Figure 7 
and Table 3), the propeller is not exposed to higher peak loads than those 
to which it is exposed during full-power steady-ahead operation. 
In contrast to the peak loads, for most components the largest time- 
average loads per revolution occurred at the first experimental condition 
(V=2.65 knots, n=10.21 revolutions per second, J=0.64) during the simulated 
acceleration maneuver. The largest measured hydrodynamic force and moment 
components, F andM_, yield (F /E )=1.21 and (M /M = 
*y vy *y MAX “H,SP Yu,MAx YH,SP 
1.29, whereas for total loading (F pe )=1.16 and (M / Mou) =) leepoulie 
SP YMax Sp 
The conditions (FL /F ) > (F /F +) and (M /M ys 
ele pisie H,MAX “H,SP age YH,MAX H,SP 
(M /M ) occur because the centrifugal and hydrodynamic components are 
Ymax sp 
additive for Fy and Mt (i.e., they have the same signs) and the hydro- 
dynamic loads increase with decreasing rotational speed n, whereas the 
centrifugal loads decrease with decreasing n. 
Higher time-average and peak loads than those shown in Figures 20 
and 22 could, of course, be developed during acceleration maneuvers, 
depending on values of v, nh, and P. 
Figure 21 shows the variation in the radial center of longitudinal 
FOGCe is and radial center of tangential force, r . These results 
F 
iE Vy 
show that the time-average radial centers of these force components vary 
F 
39 
