Abstract: Provided herein are various enhanced systems, apparatuses, and techniques for fluid displacement along a fluid link using a pump. One example includes an assembly including a pump and a normally-open valve coupled along a fluid link between a reservoir and an accumulator. The pump can move fluid from the reservoir to the accumulator to pressurize the accumulator or from the accumulator to the reservoir to drain the accumulator. After filling the accumulator with fluid, the pump can close the valve by establishing a reverse pressure differential across the valve. To refill or drain the accumulator, the pump can open the valve by establishing a forward pressure differential across the valve, then moving fluid in a reverse flow direction at a specified flow rate below a flow rate threshold.

Abstract: Provided herein are various improvements to rocket engine components and rocket engine operational techniques. In one example, a rocket engine propellant injection apparatus is provided that includes a manifold formed into a single body by an additive manufacturing process and comprising a fuel cavity and an oxidizer cavity. The manifold also includes one or more propellant feed stubs, the one or more propellant feed stubs protruding from the manifold and formed into the single body of the manifold by the additive manufacturing process, with at least a first stub configured to carry fuel to the fuel cavity and at least a second stub configured to carry oxidizer to the oxidizer cavity. The manifold also includes a plurality of injection features formed by apertures in a face of the manifold, ones of the plurality of injection features configured to inject the fuel and the oxidizer for combustion.

Abstract: Provided herein are various improvements to rocket engine components and rocket engine operational techniques. In one example, a rocket engine propellant injection apparatus is provided that includes a manifold formed into a single body by an additive manufacturing process and comprising a fuel cavity and an oxidizer cavity. The manifold also includes one or more propellant feed stubs, the one or more propellant feed stubs protruding from the manifold and formed into the single body of the manifold by the additive manufacturing process, with at least a first stub configured to carry fuel to the fuel cavity and at least a second stub configured to carry oxidizer to the oxidizer cavity. The manifold also includes a plurality of injection features formed by apertures in a face of the manifold, ones of the plurality of injection features configured to inject the fuel and the oxidizer for combustion.

Abstract: Provided herein are various improvements to rocket engine components and rocket engine operational techniques. In one example, a rocket engine propellant injection apparatus is provided that includes a manifold formed into a single body by an additive manufacturing process and comprising a fuel cavity and an oxidizer cavity. The manifold also includes one or more propellant feed stubs, the one or more propellant feed stubs protruding from the manifold and formed into the single body of the manifold by the additive manufacturing process, with at least a first stub configured to carry fuel to the fuel cavity and at least a second stub configured to carry oxidizer to the oxidizer cavity. The manifold also includes a plurality of injection features formed by apertures in a face of the manifold, ones of the plurality of injection features configured to inject the fuel and the oxidizer for combustion.

Abstract: Fuel fill apparatus for use with fuel tanks are described. An example fuel fill apparatus includes a body defining a fuel fill passageway, a first plurality of longitudinal ribs positioned in the fuel fill passageway, and a second plurality of longitudinal ribs positioned adjacent the first longitudinal ribs. The first and second longitudinal ribs position an end of a fuel nozzle in the fuel fill passageway. A deflector is positioned in the fuel fill passageway adjacent an end of the first and second plurality of ribs to direct fuel vapors away from an aspirator of the fuel nozzle when the fuel nozzle is inserted in the fuel fill passageway.

Abstract: Provided herein are various improvements to rocket engine components and rocket engine operational techniques. In one example, a rocket engine propellant injection apparatus is provided that includes a manifold formed into a single body by an additive manufacturing process and comprising a fuel cavity and an oxidizer cavity. The manifold also includes one or more propellant feed stubs, the one or more propellant feed stubs protruding from the manifold and formed into the single body of the manifold by the additive manufacturing process, with at least a first stub configured to carry fuel to the fuel cavity and at least a second stub configured to carry oxidizer to the oxidizer cavity. The manifold also includes a plurality of injection features formed by apertures in a face of the manifold, ones of the plurality of injection features configured to inject the fuel and the oxidizer for combustion.

Abstract: Fuel fill apparatus for use with fuel tanks are described. An example fuel fill apparatus includes a body defining a fuel fill passageway, a first plurality of longitudinal ribs positioned in the fuel fill passageway, and a second plurality of longitudinal ribs positioned adjacent the first longitudinal ribs. The first and second longitudinal ribs position an end of a fuel nozzle in the fuel fill passageway. A deflector is positioned in the fuel fill passageway adjacent an end of the first and second plurality of ribs to direct fuel vapors away from an aspirator of the fuel nozzle when the fuel nozzle is inserted in the fuel fill passageway.

Abstract: Fuel fill apparatus for use with fuel tanks are described. An example fuel fill apparatus includes a body to removably couple to a neck of a fuel tank. The body has an opening to receive a fuel nozzle and guide liquid fuel from the fuel nozzle to a cavity of the fuel tank. A nozzle retainer retains the fuel nozzle in the opening. A positioner in the opening offsets the fuel nozzle relative to a central axis of the opening such that an aspirator of the fuel nozzle is positioned adjacent an inner wall of the opening when the fuel nozzle is inserted in the opening. The positioner maintains a fuel nozzle outlet opening substantially parallel relative to a central axis of the opening during a fueling event.

Abstract: Fuel fill apparatus for use with fuel tanks are described. An example fuel fill apparatus includes a body to removably couple to a neck of a fuel tank. The body has an opening to receive a fuel nozzle and guide liquid fuel from the fuel nozzle to a cavity of the fuel tank. A nozzle retainer retains the fuel nozzle in the opening. A positioner in the opening offsets the fuel nozzle relative to a central axis of the opening such that an aspirator of the fuel nozzle is positioned adjacent an inner wall of the opening when the fuel nozzle is inserted in the opening. The positioner maintains a fuel nozzle outlet opening substantially parallel relative to a central axis of the opening during a fueling event.