Selectable mode ramjet/rocket jet engine

Abstract

The jet engine comprising a ramjet air path extending from an intake, into a combustion chamber, and out an exhaust nozzle, a fuel inlet leading into the combustion chamber, an oxidizer inlet leading into the combustion chamber and a partition being operable to selectively close the ramjet air path upstream of the combustion chamber to allow operation of the jet engine in rocket mode and open the ramjet air path to allow operation of the jet engine in ramjet mode.

1 . A jet engine comprising:
 a ramjet air path extending from an intake, into a combustion chamber, and out an exhaust nozzle;   a fuel inlet leading into the combustion chamber;   an oxidizer inlet leading into the combustion chamber; and   a partition being operable to selectively close the ramjet air path upstream of the combustion chamber to allow operation of the jet engine in rocket mode, and to selectively open the ramjet air path to allow operation of the jet engine in ramjet mode.   
     
     
         2 . The jet engine of  claim 1 , wherein the partition is in the form of at least two mating, apertured, flame walls of the combustion chamber, the flame walls forming a seal closing the ramjet air path by abutment against one another with the apertures of a first flame walls being disaligned with the apertures of a second flame walls. 
     
     
         3 . The jet engine of  claim 2 , wherein the first flame wall is movable away from the second flame wall to open the ramjet air path. 
     
     
         4 . The jet engine of  claim 3 , further comprising a linear piston actuator mounted between the first flame walls and a casing of the jet engine, the piston actuator being operable to selectively move the first flame wall away and against the second flame wall. 
     
     
         5 . The jet engine of  claim 2 , wherein the flame walls are of a surface of revolution shape, having a narrow tip at the intake, and broadening out from the tip to the exhaust nozzle. 
     
     
         6 . The jet engine of  claim 5 , wherein the surface of revolution shape is a conical shape. 
     
     
         7 . The jet engine of  claim 1 , further comprising an actuator operable to close the partition when subjected to a pressure of an oxidizer via the oxidizer inlet. 
     
     
         8 . The jet engine of  claim 7 , wherein the actuator is biased by a pressure of fuel via the fuel inlet to maintain the partition open in the absence of the oxidizer pressure via the oxidizer inlet. 
     
     
         9 . The jet engine of  claim 7 , wherein the actuator is a linear actuator. 
     
     
         10 . The jet engine of  claim 9 , wherein the linear actuator comprises:
 a cylinder housing a piston head in a sealed, slidable engagement, the piston head being connected to a piston rod, the piston rod extending outside the cylinder;   an oxidizer line leading to one side of the piston head, and extending out the cylinder to the oxidizer inlet; and   a fuel line leading to the other side of the piston head, and extending out of the cylinder, to the fuel inlet, with one of the fuel line and the oxidizer line extending across the piston head and inside the piston rod.   
     
     
         11 . The jet engine of  claim 10 , wherein the other one of the fuel line and the oxidizer line also extends inside the piston rod. 
     
     
         12 . The jet engine of  claim 10 , wherein one of the piston and the cylinder is fixed relative to a casing of the jet engine, and the other one of the piston and the cylinder is fixed to a slidable component which slides into sealing abutment against a seat component when the piston head is subjected to the oxidizer pressure thereby closing the partition. 
     
     
         13 . A method of operating a jet engine, comprising:
 providing a ramjet air path extending from an intake, into a combustion chamber, and out an exhaust nozzle;   providing a fuel inlet leading into the combustion chamber;   providing an oxidizer inlet leading into the combustion chamber;   providing a partition being operable to selectively close the ramjet air path upstream of the combustion chamber to allow operation of the jet engine in rocket mode, and to selectively open the ramjet air path to allow operation of the jet engine in ramjet mode;   operating the jet engine in a ramjet mode including supplying fuel through the fuel inlet and maintaining the partition open; and   operating the jet engine in a rocket mode by supplying fuel through the fuel inlet and oxidizer through the oxidizer inlet and maintaining the partition closed,
 wherein the step of operating the jet engine in the rocket mode is performed after the step of operating the jet engine in the ramjet mode. 
   
     
     
         14 . The method of operating a jet engine of  claim 13 , wherein the same fuel is supplied during both the ramjet mode and the rocket mode. 
     
     
         15 . The method of operating a jet engine of  claim 13 , further comprising:
 operating the jet engine in the rocket mode, including supplying fuel through the fuel inlet, supplying oxidizer through the oxidizer inlet, and maintaining the partition closed,
 wherein the step of operating the jet engine in the rocket mode occurs prior to operating the jet engine in the ramjet mode.