Rocket engine nozzle comprising a jet separation control system

Abstract

The invention relates to a rocket engine nozzle comprising a system for controlling jet separation of the flow in the nozzle, wherein said control system exhibits a plurality of separation triggering elements ( 5, 10 ) arranged in such a way as to generate, from mutually spaced initiation points ( 9 ), distinct zones ( 6 ) of jet separation, so as to form a three-dimensional separation of the flow. The flow control system can exhibit at least two triggering elements ( 5, 10 ).

1 . A rocket engine nozzle comprising a system for controlling jet separation of the flow in the nozzle, wherein said control system exhibits a plurality of separation triggering elements ( 5 ,  10 ) arranged in such a way as to generate, from mutually spaced initiation points ( 9 ), distinct zones ( 6 ) of jet separation, so as to form a three-dimensional separation of the flow.  
     
     
         2 . The nozzle as claimed in  claim 1 , wherein the flow control system exhibits a device for injecting fluid through a wall of the nozzle, which exhibits, in at least one injection cross section substantially perpendicular to the axis of the nozzle, at least two independent injection orifices ( 5 ) distributed over the perimeter of the wall of the nozzle, each injection orifice ( 5 ) constituting a said separation triggering element inducing a said distinct zone ( 6 ) of jet separation.  
     
     
         3 . The nozzle as claimed in  claim 2 , wherein the injection orifices ( 5 ) are uniformly distributed over the perimeter of the wall of the nozzle ( 4 ).  
     
     
         4 . The nozzle as claimed in  claim 3 , wherein the injection orifices ( 5 ) are two in number and are diametrically opposed.  
     
     
         5 . The nozzle as claimed in  claim 3 , wherein the injection orifices ( 5 ) are 3 in number and are arranged at substantially 120° to one another over the perimeter of the nozzle ( 4 ).  
     
     
         6 . The nozzle as claimed in one of the preceding claims, wherein said injection cross section is arranged at a distance D from the throat ( 3 ) of the nozzle which is substantially less than the distance Do of spontaneous separation of the flow.  
     
     
         7 . The nozzle as claimed in  claim 6 , wherein the injection device exhibits a plurality of injectors ( 5 ) situated at different distances D, and a distributing device for feeding one or other of said injection cross sections ( 5 ), in such a way as to take into account the variation of said distance Do as a function of altitude.  
     
     
         8 . The nozzle as claimed in one of the preceding claims, wherein the flow control system exhibits an external stabilizing device integral with a ground-based installation and which exhibits, on the one hand, a number N(N≧2) of injection tubes ( 10 ) each of which constitutes a said separation triggering element, and which are distributed, preferably downstream of the nozzle ( 4 ), in such a way as to direct in counter-current to the main stream of the nozzle a stabilizing fluidic stream toward N impact points ( 12 ) situated downstream of the throat ( 3 ) of the nozzle ( 4 ), and on the other hand, a device (AL) for feeding the injection tubes ( 10 ) so as to feed them with fluid for a predetermined transient duration of ignition before takeoff, with a flow rate which is sufficient for each impact point ( 12 ) to induce a different zone of jet separation of the nozzle.  
     
     
         9 . The nozzle as claimed in  claim 8 , wherein the injection tubes ( 10 ) are parallel to the axis of the nozzle.  
     
     
         10 . The nozzle as claimed in either of claims  8  and  9 , wherein the injection tubes ( 10 ) are arranged at the outlet of the nozzle ( 4 ) exit ( 8 ).  
     
     
         11 . The nozzle as claimed in one of  claims 8  to  10 , wherein the impact points ( 12 ) of the external stabilizing device are uniformly distributed over the perimeter of the wall of the nozzle.  
     
     
         12 . The nozzle as claimed in  claim 11 , wherein the impact points ( 12 ) of the external stabilizing device are two in number and are diametrically opposed.  
     
     
         13 . The nozzle as claimed in  claim 11 , wherein the impact points ( 12 ) of the external device are three in number and are arranged at substantially 120° to one another over the perimeter of the nozzle.