Prospects for Unconventional Marine Propulsion Devices 

 D Drag ■' ■ • 



F Weight of fuel 



Hl Total head loss in system excluding pump 



k = Vj v^ Jet velocity ratio 



k^ Appendage resistance factor 



\ = % 2~ System head loss coefficient 



L Lift 



M Weight of machinery installation 



N Propeller or rotor rate of rotation 



P Static pressure at axis of propulsion device 



p Static pressure in cavity 



p Power in general 



Pg Power output of propulsion machinery 



p^ ''■' Power delivered to propulsion device 



Pg ^ RV Useful or effective power based on ship resistance in- 



cluding appendages 



Pn °^ Rf^V Useful or effective power based on ship resistance with- 



out appendages 



Thrust power from propulsion device 



Resistance of ship including propulsion appendages 



Resistance of ship without propulsion appendages 



Thrust deduction fraction 



Effective thrust from propulsion device 



Speed of ship 



Inlet velocity to propulsion device 



Nozzle or exit velocity 



915 



