Liquid rocket engine tap-off power source
A liquid rocket engine integrates tap-off openings at a combustion chamber wall to direct exhaust from the combustion chamber to a tap-off manifold that provides the exhaust to one or more auxiliary systems, such as a turbopump that pumps oxygen and/or fuel into the combustion chamber. The tap-off opening passes through a fuel channel formed in that combustion chamber exterior wall and receives fuel through a fuel opening that interfaces the fuel channel and tap-off opening. The tap-off manifold nests within a fuel manifold for thermal management. The fuel channel directs fuel into the combustion chamber through fuel port openings formed in the combustion chamber, the fuel port openings located closer to a headend of the combustion chamber than the tap-off openings.
1. A method for powering an auxiliary system of a liquid rocket engine, the method comprising:
pressurizing fuel in a fuel manifold to pump the fuel through fuel channels formed in a wall of a combustion chamber and out fuel ports into the combustion chamber;
injecting oxygen towards the combustion chamber wall from an oxygen injector disposed at a headend of the combustion chamber;
passing exhaust gas generated by burning fuel from the combustion chamber to a tap-off manifold through tap-off openings formed in the combustion chamber wall;
locating the fuel ports between the headend and the tap-off openings;
cooling the tap-off manifold with fuel disposed around the tap-off manifold;
directing the exhaust gas from the tap-off manifold to the auxiliary system; and
powering the auxiliary system with the exhaust gas.
2. The method of claim 1 further comprising:
directing at least some of the fuel from the fuel channels into the tap-off openings.
3. The method of claim 2 wherein the directing at least some of the fuel further comprises interfacing the fuel channel and tap-off opening with an elliptical-shaped opening formed between the fuel channel and the tap-off opening.
4. The method of claim 1 wherein the auxiliary system comprises a turbopump, the method further comprising:
pumping the fuel into the fuel manifold with the turbopump;
pumping the oxygen to the oxygen injector with the turbopump; and
directing exhaust of the turbopump to an exhaust from the combustion chamber.
5. The method of claim 1 wherein:
at least some of the oxygen injects along the headend substantially perpendicular to the combustion chamber wall; and
exhaust entering the tap-off openings has an oxygen-rich composition.
6. The method of claim 5 wherein fuel directed into the tap-off opening mixes with the exhaust to establish a substantially volume distributed combustion.