Marine Vessel Propulsion System with a Nozzle and a Propeller

Abstract

The invention relates to a ship propulsion system comprising a nozzle body and a propeller enclosed by said nozzle body; the nozzle body has an inner surface which forms a flow channel, and further an outer surface; a constriction is situated between the inlet plane and the outlet plane of the flow channel; as seen in an axial sectional view, the inner boundary surface of the flow channel has a first contour between the inlet plane and the constriction, and a second contour between the constriction and the outlet plane; the constriction is situated at a distance of 0.25 to 0.55 of the length of the nozzle body as measured from the inlet plane, preferably 0.3 to 0.4.

1 - 9 . (canceled) 
     
     
         10 : A ship propulsion system comprising:
 a nozzle body and a propeller enclosed by the nozzle body;   wherein the nozzle body having an inside surface forming a flow channel, and the nozzle body further having an outside surface;   wherein a constriction is situated between an inlet plane and an outlet plane of the flow channel;   wherein an inner boundary surface of the flow channel has a first contour between the inlet plane and the constriction, and a second contour between the constriction and the outlet plane;   wherein the constriction is situated at a distance of 0.25 to 0.55 of the length of the nozzle body as measured from the inlet plane;   wherein the contour follows the following rational function:
     y =( a+bx )/(1+ cx+dx   2 ) 
   with the following coefficients for a length of one meter of the nozzle body:
   a=0.21480055 
   b=−0.6380295
 
   c=22.43205 
   d=−23.304763
 
   wherein the coefficients are scaled accordingly for deviating lengths of the nozzle body.   
     
     
         11 : The ship propulsion system according to  claim 10 , wherein the second contour follows the following quadratic function:
     y=a+bx   2      with the following coefficients for a length of one meter of the nozzle body:
   a=−0.01965953
 
   b=0.01381632 
   c=0.09219007 
   wherein the coefficients are scaled accordingly for deviating lengths of the nozzle body.   
     
     
         12 : The ship propulsion system according to  claim 10 , wherein the outside surface of the nozzle body has a contour as a polynomial of sixth order according to the following function:
     y=a+bx+cx   2   +dx   3      with the following coefficients for a length of one meter of the nozzle body:
   a=0.24418034 
   b=0.919041095 
   c=−8.7136152
 
   d=29.591049 
   e=−51.371726
 
   f=43.581168 
   g=−14.141404
 
   wherein the coefficients are scaled accordingly for deviating lengths of the nozzle body.   
     
     
         13 : The ship propulsion system according to  claim 11 , wherein the outside surface of the nozzle body has a contour as a polynomial of sixth order according to the following function:
     y=a+bx+cx   2   +dx   3      with the following coefficients for a length of one meter of the nozzle body:
   a=0.24418034 
   b=0.919041095 
   c=−8.7136152
 
   d=29.591049 
   e=−51.371726
 
   f=43.581168 
   g=−14.141404
 
   wherein the coefficients are scaled accordingly for deviating lengths of the nozzle body.   
     
     
         14 : The ship propulsion system according to  claim 10 , wherein a deviation of the aforementioned numbers by ±10 percent, at least by ±5 percent. 
     
     
         15 : The ship propulsion system according to  claim 10 , wherein the propeller is situated downstream of the constriction. 
     
     
         16 : The ship propulsion system according to  claim 11 , wherein the propeller is situated downstream of the constriction. 
     
     
         17 : The ship propulsion system according to  claim 12 , wherein the propeller is situated downstream of the constriction. 
     
     
         18 : The ship propulsion system according to  claim 13 , wherein the propeller is situated downstream of the constriction. 
     
     
         19 : The ship propulsion system according to  claim 14 , wherein the propeller is situated downstream of the constriction. 
     
     
         20 : The ship propulsion system according to  claim 10 , wherein the first contour is at least approximately a hyperbola. 
     
     
         21 : The ship propulsion system according to  claim 11 , wherein the first contour is at least approximately a hyperbola. 
     
     
         22 : The ship propulsion system according to  claim 12 , wherein the first contour is at least approximately a hyperbola. 
     
     
         23 : The ship propulsion system according to  claim 13 , wherein the first contour is at least approximately a hyperbola. 
     
     
         24 : The ship propulsion system according to  claim 14 , wherein the first contour is at least approximately a hyperbola. 
     
     
         25 : The ship propulsion system according to  claim 15 , wherein the first contour is at least approximately a hyperbola. 
     
     
         26 : The ship propulsion system according to  claim 16 , wherein the first contour is at least approximately a hyperbola. 
     
     
         27 : The ship propulsion system according to  claim 10 , wherein the second contour is at least approximately rectilinear, the flow channel expands between the constriction and the outlet plane, and the opening angle between the second contour and the longitudinal axis of the flow channel lies between 5 and 15°. 
     
     
         28 : The ship propulsion system according to  claim 10 , wherein the constriction is situated at a distance of 0.3 to 0.4 of the length of the nozzle body as measured from the inlet plane. 
     
     
         29 : A ship including the ship propulsion system of  claim 10 .