Solid propellant management control system and method

Abstract

Systems and methods of controlling solid propellant burn rate, propellant gas pressure, propellant gas pressure pulse shape, and propellant gas flow rate, rely on the position of a throttling valve. A throttling valve that is movable to a control position is disposed downstream of, and in fluid communication with, a solid propellant gas generator, and in parallel with a plurality of reaction control valves. The solid propellant in the solid propellant gas generator is ignited, to thereby generate propellant gas. The throttling valve is moved to a control position to attain a desired solid propellant burn rate, propellant gas pressure, and/or propellant gas pressure pulse shape.

1 . A solid propellant management control system, comprising:
 a vessel defining a combustion chamber;   a solid propellant disposed within the combustion chamber, the solid propellant configured to generate propellant gas upon being ignited;   a plurality of reaction control valves in fluid communication with the combustion chamber, each reaction control valve coupled to receive reaction control signals and responsive thereto to selectively move between a closed position and a full-open position;   a throttling valve in fluid communication with the combustion chamber and coupled to receive throttling valve control signals, the throttling valve responsive to the throttling control signals to move to a control position that results in a desired combustion chamber pressure; and   a controller operable to selectively supply the reaction control signals and the throttling valve control signals.   
   
   
       2 . The system of  claim 1 , further comprising:
 a plurality of reaction control thrust nozzles, each reaction control thrust nozzle disposed downstream of, and in fluid communication with, one of the reaction control valves, each reaction control thrust nozzle configured to generate a thrust when propellant gas flows there-through; and   an axial thrust nozzle disposed downstream of, and in fluid communication with, the throttling valve, the axial thrust nozzle configured to generate an axial thrust when propellant gas flows there-through.   
   
   
       3 . The system of  claim 1 , further comprising:
 a plurality of reaction control thrust nozzles, each reaction control thrust nozzle disposed downstream of, and in fluid communication with, one of the reaction control valves, each nozzle configured to generate a thrust when propellant gas flows there-through; and   a plurality of null thrust nozzles disposed downstream of, and in fluid communication with, the throttling valve, the null thrust nozzles each configured to generate a thrust in opposing directions when propellant gas flows there-through.   
   
   
       4 . The system of  claim 1 , further comprising:
 a main thrust nozzle in fluid communication with the combustion chamber to at least selectively receive propellant gas therefrom.   
   
   
       5 . The system of  claim 1 , further comprising:
 a manifold in fluid communication with the combustion chamber, each reaction control valve, and the throttling valve.   
   
   
       6 . The system of  claim 1 , further comprising:
 a flight computer operable to supply flight control signals representative of a commanded aircraft flight path,   wherein the controller is responsive to the flight control signals to selectively supply the reaction control signals and the throttling valve control signals.   
   
   
       7 . The system of  claim 1 , wherein the controller is further operable to selectively supply the throttling valve control signals to control solid propellant burn rate. 
   
   
       8 . The system of  claim 1 , wherein the controller is further operable to selectively supply the throttling valve control signals to control propellant gas pressure in the combustion chamber. 
   
   
       9 . The system of  claim 1 , wherein the controller is further operable to selectively supply the throttling valve control signals to control generation of propellant gas pressure pulses in the combustion chamber. 
   
   
       10 . The system of  claim 1 , wherein:
 the propellant gas pressure pulses each have a pulse shape; and   the controller is further operable to selectively supply the throttling valve control signals to control the pulse shape of the propellant gas pressure pulses.   
   
   
       11 . The system of  claim 1 , wherein the throttling valve is selected from the group consisting of a pintle valve and a poppet valve. 
   
   
       12 . The system of  claim 1 , further comprising:
 a sensor operable to sense a parameter representative of combustion chamber pressure and to supply a feedback signal representative thereof to the control,   wherein the controller is responsive to the feedback signal to selectively supply the throttling valve control signals.   
   
   
       13 . The system of  claim 12 , wherein the sensor includes one or more of a propellant gas temperature sensor, a propellant gas pressure sensor, and a throttling valve position sensor. 
   
   
       14 . A method of managing propellant gas generation, comprising the steps of:
 disposing a solid propellant in a vessel;   disposing a plurality of reaction control valves downstream of, and in fluid communication with, the vessel, each of the reaction control valves movable between a closed position and a full-open position;   disposing a throttling valve downstream of, and in fluid communication with, the vessel, the throttling valve movable to a plurality of control positions;   igniting the solid propellant in the vessel to thereby generate propellant gas;   moving the throttling valve to a control position to attain a desired propellant gas pressure.   
   
   
       15 . The method of  claim 14 , further comprising:
 controlling the control position of the throttling valve to control solid propellant burn rate.   
   
   
       16 . The method of  claim 14 , further comprising:
 controlling the control position of the throttling valve to control generation of propellant gas pressure pulses in the vessel.   
   
   
       17 . The method of  claim 16 , wherein the propellant gas pressure pulses each have a pulse shape, and wherein the method further comprises:
 controlling the control position of the throttling valve to control the pulse shape of the propellant gas pressure pulses.   
   
   
       18 . The method of  claim 14 , further comprising:
 disposing an reaction control thrust nozzle downstream of each reaction control valve, each reaction control thrust nozzle configured to generate a thrust when propellant gas flows there-through; and   at least partially controlling the thrust that may be generated by each nozzle by controlling the control position of the throttling valve.   
   
   
       19 . The method of  claim 14 , further comprising:
 controlling the position of the throttling valve based on a vehicle mission profile.   
   
   
       20 . The method of  claim 14 , further comprising:
 controlling the control position of the throttling valve to control mass flow rate of the propellant gas from the vessel through the throttling valve; and   ejecting the propellant gas that flows through the throttling valve in one or more directions that result in a substantially zero net thrust.