interaction analysis (CALCTD) . A block diagram illustrating this procedure 

 is given in Figure 5. It should be noted that the first, and most time- 

 consuming task, is to assemble the necessary hull offsets and propeller 

 geometry and loading data in a suitable form. 



Example calculations have been conducted for several propeller body- 

 of-revolution configurations, with and without cruciform stern appendages. 

 These examples were chosen to illustrate important features of the analy- 

 tical method and to provide experimental verification of the theory. A 

 summary of the results is presented in Table 1 showing pertinent character- 

 istics of each propeller-hull configuration and a comparison of predicted 

 and measured thrust deduction fractions. Detailed numerical results and 

 discussions of each example are given in the following sections. 



EXAMPLE 1: APPENDED SERIES 58 FORM 



As a first check on the computational procedure, a Series 58 Form 

 originally calculated by Beveridge was selected for analysis. The hull is 

 a streamlined body of revolution, DTNSRDC Model 4620, fitted with cruciform 

 stern appendages. The propeller, DTNSRDC 3638, is a 5-bladed wake-adapted 

 design located 98 percent of the hull length from the bow. Offsets and 

 particulars of the hull are listed in Table 2. A drawing of the propeller 

 is given in Figure 6. 



The quadrilateral representation of the hull and appendages is illus- 

 trated in Figure 7 (identical to that used by Beveridge) . Note that for 

 ease of computation, the horizontal control surfaces are also used to 

 represent the upper and lower rudders and the forebody is approximated by 

 reflecting the afterbody about the hull midlength (this latter simplifica- 

 tion is shown to be valid in later examples). The propeller circulation 

 and hydrodynamic pitch distributions, r(r) and 2T7r tan 3.(r), were obtained 

 from lifting-line calculations and are shown in Figure 8. The axial and 

 radial propeller field point velocities induced at control points on the 

 body boundary are presented in Figure 9. Since the propeller has no rake, 

 the lifting-surface corrections arise solely from blade thickness and chord- 

 wise load distribution. These effects are seen to decay more rapidly than 

 the lifting-line disturbance field, contributing less than 10 percent at 

 distances beyond one propeller radius. 



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