27r 

 LOj = (jip = / Tp = pitch period 



Determination of ALVIN Mass 



ALVIN weight in air prior to sinking = 33,051 pounds with MBT full. From discus- 

 sions with Ocean Systems, Incorporated, 



wt in water wt. of entrain ed water 24,300 



Effective ALVIN IVIass = + + (6) 



g 9 9 



24,300 . . 



where the term is the added mass effect based on ALVIN surface characteristics. 



ttD^ (6.8341^ J 



Volume of Pressure Hull = = = 167 ft. 



where D = inside diameter of ALVIN pressure sphere (ft.) 



Q 



Assume the entrained water volume = 90% of the pressure hull volume = .9(167) = 150 ft. 

 Then weight of entrained water = 64 x 150 = 9600 lbs. 



lA/ 



m = — 

 9 



(96OO + 24,30o\ W 



+ \ 1 =— + 7050 (7) 



\ 322 I g 



Determination of Damping Factor 



The force due to damping can be expressed as 



Fq = - C^ PS (x)^ (8) 



wiiere Cq = coefficient of drag 



S = projected area of ALVIN 

 p = density of salt water 



66 



