Acoustic igniter

摘要

An acoustic resonance igniter uses gas expanding through a nozzle to form a sonic, or under-expanded supersonic, jet directed against the opening of a blind resonance cavity in a central body, setting up a high-frequency sonic resonance which heats the gas within the cavity. A pintle extends coaxially with the nozzle and injects liquid propellant into the jet. The liquid propellant ignites with the heated gas within the resonance cavity forming combustion gases. The combustion gases flow through openings in a flange which supports the resonance cavity into a combustion chamber in the same direction as the gas jet flows. The liquid propellant is injected from within the support flange in the direction of combustion gas flow to film cool the combustion chamber wall and the flange and the central body supported by the flange. The acoustic resonance igniter may form a rocket engine ignition torch or a RCS thruster.

主权项

1. An acoustic resonance igniter for a rocket engine comprising:
a source of compressed gas; at least one source of pressurized liquid propellant; a gas nozzle defining a nozzle axis, the gas nozzle connected to a gas chamber connected to the source of compressed gas; a pintle defining an axis, portions of the pintle forming an axial liquid flow path connected to the source of pressurized liquid propellant, the pintle positioned within the gas nozzle aligned along the nozzle axis, and having portions defining a liquid propellant outlet directed along the axis of the pintle; a flange having an upper surface and a lower surface, and supporting a central body, wherein portions of the central body define a resonance cavity, the resonance cavity having a resonance cavity opening in the upper surface of the flange which is spaced from the gas nozzle along the nozzle axis; an ignition chamber defined between the gas nozzle and the resonance opening in the upper surface of the flange; wherein the pintle liquid propellant outlet is directed along the axis of the gas nozzle at the resonance cavity opening in the upper surface of the flange; a combustion chamber separated from the ignition chamber by the flange, and having an interior wall defining a combustion space; wherein the gas nozzle and the resonance cavity are arranged to produce hot gas in the resonance cavity, and the pintle is arranged to supply liquid propellant to the hot gas to initiate combustion; wherein portions of the flange define a plurality of first openings through the flange which are separated by support members formed by portions of the flange which extend from the central body to portions of the flange which are radially beyond the first openings in the flange, wherein the first openings and support members are positioned radially outwardly from the resonance cavity opening, so that gases can flow from the ignition chamber through the first openings into the combustion chamber; wherein the flange has portions defining internal passageways along the support members, the internal passageways connected to the at least one source of pressurized liquid propellant; wherein the flange has portions which form a plurality of second openings extending to the lower surface of the flange, said second openings arranged to provide for flow of the pressurized liquid propellant in the internal passageways along the support members, and to spray the pressurized liquid propellant on exterior surfaces of the central body and on the combustion chamber interior wall.