Vehicle Dynamics Associated with. Submarine Rescue 



= 530 n^ + 80 un + 35. 2 u^ + 22{vd^ + w^)'^^ + 131 A ; 



'P ■ "P' 



u < 0, n > 



468 n^ - 8 un + 15. 2 u^ + 22(vd + w^)'^^ + 131 A ; 



■p ■ "P' 



u < 0, n < 



Mprop= - "7^5 nwp 



306 nw- 



Nprop= 765 nvp 



= 306 nv. 



n > 

 n < 

 n > 

 n < 



where 



Vp = V - 25. 5 r 



■w=w+25.5q 



Ducted Thrusters 



There are two pairs of ducted thrusters used for maneuvering 

 in the pitch and yaw planes, as shown in Fig. 2. The four-bladed 

 propellers are 18 inches in diameter and have a maximum speed of 

 9.8 revolutions per second and produce side force through a combi- 

 nation of impeller thrust and a change in the pressure distribution on 

 the hull (Fig. 7 and Ref. 7). The thrust due to variation in pressure 

 distribution is very dependent on forward speed and the total thrust 

 coefficient for the steady state n = condition was measured at 

 NSRDC as a function of forward speed (Ref. 9). Force coefficients 

 derived from this test are shown in Figs. 5 and 6 as a function of 

 u/|n| where n is the propeller RPS, The steady state force is 

 obtained from the relationships 



2 * 

 Xfhr mf = rimfTj 



2 * 

 ^ thr ma ~ ^mcr'- 4 



Yfhryf =^yf l^yflT 



1141 



