VehiQle Dynamics Associated with Submarine Rescue 



o 



O 

 u 



LU 



O 



o 



o 

 z 

 < 



(J 



u 



.2 



y 0.8 



0.4 



-0.2 



-0.6 



O -1.0 



-2.0 



•1.6 -1.2 -0.8 -0.4 



0.4 



0.8 



1.2 



1.6 2.0 



APPARENT SPEED COEFFICIENT, Ja ' -RB 



Fig, 6. 



Characteristics Curves for DSRV Propeller 

 (Note: Data from model tests conducted at 

 NSRDC (Ref. 8) ) 



The coefficients a, b, c have been evaluated separately for each 

 quadrant of the propeller curves, and the resulting thrust and torque 

 coefficients are used as an expression of the steady and transient 

 characteristics of the propeller forces and moments. During 

 maneuvering the propeller may also experience velocities normal to 

 its axis. The resulting effect on the propeller thrust in the axial 

 direction and torque about the roll axis have been estimated and the 

 form of the coefficients can be rewritten including this effect as 

 follows: 



2 2 2 1/2 



K = a +bJ^, +cJy +d{J, + J^) 



where 



J.. = 



nd 



1139 



