Vehiole Dynamias Associated with Submarine Rescue 



1 KNOT ATHWARTSHIP CURRENT, FORWARD HATCH, DISSUB ROLLED 22.5 DEC. 



D5RV BOW UP (e 

 e •= 22.5* 



5 10 15 20 25 30 

 DISTANCE DSRV TO DISSUB (FT) 



10 15 20 25 30 

 DISTANCE (FT) 



DSRV PITCH ANGLE) 



-200 



4000 r 



2000 



10 15 20 

 DISTANCE (FT) 



10 15 20 25 

 DISTANa (FT) 



30 



Fig. 33. Interaction^ Forces and Moments 



rather is in a relatively arbitrary direction. The effects of heading 

 changes on the interaction problem are illustrated in Fig. 34, 



First of all, as the DSRV heading is changed, Euler angle 

 variations occur (Fig. 34a). Where initially the DSRV was not re- 

 quired to list at all, it must now both list and trim, and can no 

 longer make precise list and trim adjustments prior to landing. 

 Concurrent with these changes, the free stream current components 

 change with heading (Fig, 34b) which nmust be conapensated appropri- 

 ately. 



Assuming that the ideal heading corresponds to zero sway 

 force, the variation of optimum heading with distance to hatch is 

 shown in Fig. 34c, The optimum relative heading is approximately 

 30 degrees, with a significant heading change required as the separa- 

 tion is decreased. It will be noted from Fig. 34d that the zero head- 

 ing yaw angle does not correspond to the zero yaw moment angle. 

 This is due to the horizontal gradients in fluid velocity along the 

 length of the DSRV. Thus, there is no yaw plane equilibrium con- 

 dition, and yaw plane control becomes a more severe problem than 



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