Pallabazzer 





a; 



1 Water inlet 



2 - Pump or propeller 



3 - Nozzle 



4 - Engine 



5 - Hull 



6 - Shaft 



7 - Shroud 



Fig. 2 



I- J v7 



Fig. 2 - Water -jet propulsive systems: 

 (a) motorboat installation; (b) hydrofoil in- 

 stallation; (c) underwater ducted propeller 



3.2 Fundamental Hypotheses 



We will outline the hypotheses necessary for the analysis. All these hy- 

 potheses have been generally adopted in the literature (Refs. [7,8,9,11,12,13, 

 14,17]), but they will be briefly justified here too. 



1110 



