Flow control system for a rocket engine with parallel fuel passage network
A flow control system ( 22 ) includes a fuel passage network ( 34 ) that has first ( 36 ) and second ( 38 ) network portions that are in a parallel flow arrangement with each other. A fueldraulic device ( 40 ) is located in the first network portion. Operation of the fueldraulic device varies flow through the first network portion. A flow restriction orifice ( 42 ) is located in the fuel passage network and is arranged in series with, and upstream of, the fueldraulic device. The flow restriction orifice is operable to generate a pressure differential that varies responsive to the flow through the first network portion. A flow control valve ( 44 ) is located in the second network portion. The flow control valve is operable responsive to the pressure differential across the flow restriction orifice to control flow through the second network portion.
1. A flow control system for a rocket engine comprising:
a fuel passage network to deliver a liquid propellant to a combustion chamber of the rocket engine, the fuel passage network including first and second network portions that are in a parallel flow arrangement with each other;
a fueldraulic device in the first network portion, wherein operation of the fueldraulic device varies flow through the first network portion, the second network portion including a bypass passage bypassing the fueldraulic device;
a flow restriction orifice in the fuel passage network, the flow restriction orifice arranged in series with, and upstream of, the fueldraulic device, the flow restriction orifice operable to generate a pressure differential that varies responsive to the flow through the first network portion; and
a flow control valve including a valve member in the bypass passage, the flow control valve including, separate from the bypass passage, a pressure port that opens to the fuel passage network upstream of the flow restriction orifice and a pressure balance passage connecting a bias member cavity of the flow control valve with a location in the fuel passage network between the flow restriction orifice and the fueldraulic device, the valve member being moveable responsive to the pressure differential across the valve member via the passage port and the pressure balance passage to control flow through the bypass passage.
2. The flow control system as recited in claim 1 , wherein the fueldraulic device is a thrust control valve.
3. The flow control system as recited in claim 1 , wherein the flow control valve is biased to an open position permitting flow through the bypass passage.
4. The flow control system as recited in claim 1 , wherein the flow control valve includes a power piston.
5. The flow control system as recited in claim 4 , wherein the pressure port operatively connects the fuel passage network with the power piston.
6. The flow control system as recited in claim 1 , wherein the fuel passage network includes a common passage downstream of the first and second network portions, at which the first and second network portions merge.
7. The flow control system as recited in claim 6 , further comprising a pump having a pump inlet connected with the common passage.
8. The flow control system as recited in claim 7 , further comprising a fuel supply passage that connects a pump outlet of the pump with the combustion chamber.
9. The flow control system as recited in claim 8 , wherein the fuel passage network includes a tap passage off of the fuel supply passage, the tap passage being connected with the first and second network portions.
10. The flow control system as recited in claim 9 , wherein the tap passage includes a pressure regulator.
11. The flow control system as recited in claim 1 , wherein the bypass passage is unbranched.
12. The flow control system as recited in claim 1 , wherein an inlet of the fueldraulic device is downstream of the flow restriction orifice.
13. A rocket engine comprising:
a combustion chamber of the rocket engine;
a pump having a pump inlet and a pump outlet;
a supply passage connecting the pump outlet with the combustion chamber; and
a fuel passage network including:
first and second network portions that are in a parallel flow arrangement with each other,
a tap passage off of the supply passage, the tap passage being connected with the first and second network portions,
a common passage downstream of the first and second network portions, at which the first and second network portions merge, the common passage connecting to the pump inlet,
a fueldraulic thrust control valve actuator in the first network portion, wherein operation of the fueldraulic thrust control valve actuator varies flow through the first network portion, the second network portion including a bypass passage bypassing the fueldraulic thrust control valve actuator,
a flow restriction orifice in the fuel passage network, the flow restriction orifice arranged in series with, and upstream of, the fueldraulic thrust control valve, the flow restriction orifice operable to generate a pressure differential that varies responsive to the flow through the first network portion, and
a flow control valve including a valve member in the bypass passage, the flow control valve including, separate from the bypass passage, a pressure port that opens to the fuel passage network upstream of the flow restriction orifice and a pressure balance passage connecting a bias member cavity of the flow control valve with a location in the fuel passage network between the flow restriction orifice and the fueldraulic thrust control valve actuator, the valve member being moveable responsive to the pressure differential across the valve member via the pressure port and the pressure balance passage to control flow through the bypass passage.
14. The rocket engine as recited in claim 13 , wherein the fuel passage network is operable to provide constant flow from the tap passage to the common passage independent of variation in flow through the fueldraulic thrust control valve actuator in the first network portion.