Johnson, Jr. 



DOUBLE SUCTION IMPELLER 



a 



a 



Fig. 6 - Multiple impeller 

 double -suction pump 





Fig. 7 - The waterjet-propelled hydrofoil craft 

 Tucumcari (designed and constructed by the 

 Boeing Company for the U.S. Navy) 



Another approach to achieving light-weight pumps has been described in 

 Ref. (3). In this approach, very-high-solidity axial or mixed flow pumps are 

 proposed and, in fact, have been tested and operated. The pumps generally op- 

 erate with rather severe cavitation at the hump condition, but Ref. (4) suggests 

 that, by properly designing the rotor, cavitation damage can be alleviated. An 

 example of the high-solidity rotor is shown in Fig. 9. Figure 10 is a photograph 



1050 



