Mathematical expressions for the normal drag coefficient for fairing 

 configurations A-1, B-1, C-1, C-2 and the NACA 0020 shape, and the side force 

 coefficient for configurations A-1, B-1, C-1, and C-2 were determined by fitting 

 the coefficients based on measured data with an equation having the general form: 



C = A + K/R^ (5) 



where A and K are constants determined by least-squares curve fitting. 



The values of A and K that provide the best fit to each of the towline 

 configuration's normal drag and side fore coefficients as a function of Reynolds 

 number are presented in Table 4. The mathematical relationships presented in this 

 table are compared to the normal drag and side force coefficients calculated from 

 the average basin data in Figures 14 through 18. 



DISCUSSION OF HYDRODYNAMIC COEFFICIENTS 

 The force coefficients presented in Figure 14 indicate that configuration A-1 

 has a normal drag coefficient that varies from approximately 0.37 to 0.17 and a 

 side-force coefficient that varies from approximately 0.09 to 0.05 at Reynolds 

 numbers from 2 x 10^ to 6 x 10^, respectively. The coefficients determined for 

 configurations B-1 and C-1 are presented in Figures 15 and 16. By comparing the 

 force coefficients for these configurations to those for the A-1 configuration, 

 the effects of increasing the percentage of alternating bevel chordwise truncation 

 may be examined. The B-1 configuration, which had a 9-percent truncation, demon- 

 strated an average reduction of approximately 15 percent in the normal drag coef- 

 ficient. The C-1 configuration, which had a 16-percent bevel truncation, demon- 

 strated an increased normal drag coefficient of approximately 19 percent at a 

 Reynolds number of 4.5 x 10 , but as the Reynolds number decreased the normal drag 

 coefficient approached the value for the A-1 configuration until at a Reynolds 

 number of 2.2 x 10^ the values of C^ were essentially the same for the C-1 and A-1 

 configurations. Although there may exist a relationship of Cg^ as a function of 

 percentage alternating bevel chordwise truncation, the limited number of samples 

 evaluated in this report do not define such a relationship and at best indicate 

 that there is little effect on Cj^ for alternating bevel truncations up to 

 chordwise truncations of 16 percent. 



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