and t] e ve lent of bhe sound source and the variations in 



itensity that accompanied bhe levelopment of cavitation from 

 the incipient stages to a bubble that enveloped the entire 

 projectile,, Later, ,°n extensive study was made en the effect 

 of nose shape on resistance to the development of cavitation 

 with special emphasis on families of ogives, spherogives, 

 and ellipsoids. Studies were also nade to determine the 

 effect of various degrees of cavitation on the drag resist- 

 ance and the control and stability characteristics cf pro- 

 ject ile shapes. 



Althon - 1 the many different torpedo shapes studied had 

 ' lely differing dimensions, they had many characteristics in 

 common. Therefore, an attempt was '"ale to ii tegrate these re- 

 sults in a general analysis of bhe effect cf body shape and 

 the size, shape, and location of control surfaces on damping 

 and iynamic stability of torpedoes. 



At the war's end, none of the studies made by the Hydro- 

 dynamics Laboratory could 'to considered as complete. In fact, 

 the research workers felt that they had only gotten started. 

 While the research program was directed wholly toward the war 

 effort, it resulted in the develop tent of equipment and tech- 

 niques of leasurement w] ich could he most usefully employed 

 in further research, not only .' : Llitary, but in civilian 

 fields* A cod example of 'hie was evident in the field of 

 cavitation research. Here practically all of the results are 

 r jually applicable to che movement of underwater bodies such 

 as irojectiles and sub arines, the operation c£ ship and 

 torpedo propellers, and the behavior cf general hydraulic 

 machinery, ui :h as centrifugal pumps end turbines for hydro- 

 electric development „ 



Studies at the Morris Dam Laboratory. 



In carrying out work on the underwater properties of 

 ; 'ojectiles there arc two main problems in lev:' sing laboratory 

 squipi eht : providing devices for Iropping or launching the 

 projectiles, and developing recording apparatus which would 

 supply accurate information c-: underwater behavior. 



A drop platform, a launching trolley, a ienduln.m launcher, 

 "n" rochet propulsion were variously used at the Korris Jar 

 Laboratory o The various launchir ie vices could ;ive, besides 

 vertical irop, a variety of speeds and angles of entry. For 

 recording purposes, h.udrophones and cameras were principally 



