Abstract: The invention relates to a device for injecting a mixture of air and fuel into a combustion chamber of a turbomachine where the supply of air is improved. The invention relates more particularly to a new type of sliding bushing.

Abstract: The invention relates to a turbomachine annular combustion chamber (1) comprising an outer axial wall (2), an inner axial wall (4), and a chamber bottom end (8) connecting the said walls, the chamber bottom end being provided with several passages (34,36,72) enabling initiation of a cooling air film (D2) along the hot inner surface (30) of the outer axial wall and initiation of a cooling air film (D1) along the hot inner surface (32) of the inner axial wall, the outer axial wall and the inner axial wall being multi-perforated roughly over their full length in order to enable reinforcement of the cooling air films. According to the invention, the outer axial wall and the inner axial wall are provided, in an upstream part, with a first zone (54,40) of perforations (38) formed such that cooling air is introduced inside the combustion chamber in reverse flow.

Abstract: A shroud for a combustion chamber bottom designed to cover fuel injectors is provided with drillings (21) on at least one of its sides to open up the cavity within the shroud and reduce noise that it produces and combustion instabilities. The drillings also have the effect of reducing instabilities and non-uniformity of the airflow around the shroud.

Abstract: The invention relates to a turbomachine annular combustion chamber (1) comprising an outer axial wall (2), an inner axial wall (4), and a chamber bottom end (8) connecting the said walls, the chamber bottom end being provided with several passages (34,36,72) enabling initiation of a cooling air film (D2) along the hot inner surface (30) of the outer axial wall and initiation of a cooling air film (D1) along the hot inner surface (32) of the inner axial wall, the outer axial wall and the inner axial wall being multi-perforated roughly over their full length in order to enable reinforcement of the cooling air films. According to the invention, the outer axial wall and the inner axial wall are provided, in an upstream part, with a first zone (54,40) of perforations (38) formed such that cooling air is introduced inside the combustion chamber in reverse flow.

Abstract: A diffuser for a turbojet engine is disclosed in which a plurality of diffuser inlets are arranged in a substantially circular array bounded by inner and outer diffuser walls and by a plurality of partitions extending generally radially from the axis of the annular diffuser. The plurality of diffuser inlets are located so as to receive air or oxidizer from the turbojet engine compressor and the radial partitions may be integrated into the compressor guide vanes. The diffuser has a plurality of sets of diffuser outlets, each set comprising a plurality of diffuser outlets arranged in a circular array about the central axis of the diffuser. The radius of each set of diffuser outlets is different from the radius of each of the other sets of diffuser outlets such that the entirety of diffuser outlets comprise a non-circular array.

Abstract: A pre-mixing injection system to feed a fuel/air mixture to a combustion zone in a turbojet engine combustion chamber is disclosed having a pre-mixing tube defining a convergent pre-mixing zone and a diverging intermediate zone between the fuel and air injection devices, and the combustion zone of the combustion chamber. The convergent pre-mixing zone has an inlet adjacent to the fuel injector and air swirlers to accept the fuel/air mixture into the pre-mixing tube. The pre-mixing zone converges in a direction from the inlet to an outlet which is in communication with the inlet of the divergent intermediate zone. The divergent intermediate zone has an outlet which is, in turn, in communication with the combustion zone of the turbojet engine combustion chamber. The divergent intermediate zone is defined by an inner wall and an outer wall spaced from the inner wall so as to define a generally frusto-conical chamber between them.

Abstract: A wall structure for a gas turbine engine structure, such as a combustion chamber or an afterburner duct is disclosed having a plurality of cooling orifices formed through the wall located in a plurality of odd and even transverse rows, each row having a plurality of cooling orifices located in a plane extending substantially perpendicular to a longitudinal axis of symmetry with the cooling orifices of each odd and even row being circumferentially offset from the cooling orifices of the adjacent upstream corresponding odd and even row. The cooling orifices have a common diameter D and are circumferentially offset a distance d such that distance d is between 0.5 D and D. The axes of the orifices in the odd numbered rows lie on a first main line extending obliquely to the longitudinal axis of symmetry and to the oxidizer air flow, and the axes of orifices on the even numbered rows lie on a second main line, also extending obliquely to the longitudinal axis of symmetry and to the oxidizer air flow.

Abstract: The present invention relates to a method and apparatus for supplying fuel to and cooling a fuel injector of a gas turbine engine having a dual head combustion chamber. The method comprises the steps of supplying a total fuel flow to the fuel injector such that at least a portion of the total fuel flow circulates through the high power injector nozzle during all operational modes of the gas turbine engine, including those modes in which the high power injector is not supplying fuel to the combustion chamber, and evacuating unused fuel from the high power injector.

Abstract: A gas flow separator for an annular combustion chamber of a gas turbine engine is disclosed in which the radially spaced apart first and second gas flow separator walls which extend axially into the combustion chamber from the combustion chamber upstream end wall each define a plurality of axially extending channels. Each of the channels extends generally axially in an upstream direction from the downstream edge of each of the separator walls such that their axial lengths are less than the axial lengths of the respective separator walls. Both the depth and the width of each of the channels increases from its upstream end point to the downstream edges of the separator walls. The channels may be circumferentially aligned with each other, or the channels of one separator wall may be circumferentially offset from the channels of the other separator wall.

Abstract: A separator for an annular gas turbine engine combustion chamber is disclosed having a plurality of separator segments arranged in a generally annular configuration to form an annular separator extending from an upstream end wall of a combustion chamber into the combustion chamber so as to separate first and second combustion zones within the combustion chamber. Each of the separator segments has a hollow interior defined by a front wall, an outer wall, an inner wall which has at least a portion tapering or converging towards the outer wall in a direction extending away from the front wall, and first and second sides. The sides define an array of holes communicating with the hollow interior, the positioning of the array of holes on a first sides being different from that of the array of holes on the second sides such that the axes of the holes are out of alignment with each other.

Abstract: A fuel/oxidizer pre-mixing combustion chamber for a turbojet engine is disclosed in which the pre-mixing device is incorporated into the upstream end wall structure of the combustion chamber. The upstream end portion of the combustion chamber, which is in communication with the oxidizer, has a plurality of generally radially extending, "V"-shaped members oriented such that the vertex of the "V" shape faces in an upstream direction. These members extend generally radially between the inner and outer walls which define the boundaries of the combustion chamber. The members define upstream edges and downstream edges which are axially the upstream edges. Fuel injectors extend radially inwardly between these members and are axially positioned between the locations of the upstream and downstream edges so as to spray fuel onto the adjacent sides of each of the members.

Abstract: A gas turbine engine is disclosed having an air compressor and a generally annular combustion chamber, with a generally annular diffuser located between the compressor and the combustion chamber so as to direct air exiting from the compressor toward the combustion chamber. The diffuser has inner and outer walls and defines an exit which is located adjacent to an opening in an upstream wall portion of the combustion forming a dome cowl. The dome cowl divides the air emanating from the diffuser exit into a primary air stream passing through the opening and one or more secondary air streams which pass between the walls defining the combustion chamber and the walls of a casing enclosing the combustion chamber assembly. A guide is associated with the diffuser for directing water in the air passing through the diffuser away from the opening such that it will not pass directly into the combustion chamber.

Abstract: A generally annular combustion chamber for a gas turbine engine is disclosed in which a plurality of generally cylindrical walls extend forwardly from an upstream end wall of the combustion chamber such that each cylindrical wall defines a cavity which is in communication with the interior of the combustion chamber. A first fuel injection head is located in each of the cylindrical walls so as to inject fuel into the cavity which is mixed with air and passes into the combustion chamber. The first fuel injection heads are located at a first axial position with respect to a longitudinal axis passing through the combustion chamber. A plurality of second fuel injection heads are located adjacent to the upstream end wall of the combustion chamber so as to spray fuel directly into the combustion chamber. The second fuel injection heads are located axially downstream of the axial positions of the first fuel injection heads.

Abstract: A low pollution combustion chamber for a turbojet engine is disclosed in which first and second combustion chambers are oriented in a counter-flow direction and both combustion chambers communicate with a separate and distinct exhaust chamber. The first combustion chamber has a fuel injector, as well as a primary oxidizer intake, and the wall bounding the first combustion chamber defines a plurality of dilution oxidizer intake orifices. The wall also defines a first exhaust orifice located approximately midway between the upstream and downstream ends of the first combustion chamber. A second combustion chamber has a second fuel injector, as well as a second primary oxidizer intake, but the wall defining the second combustion chamber does not define any dilution oxidizer intake orifices. A second exhaust orifice also communicates with the exhaust chamber.

Abstract: A combustion chamber suitable for use in a gas turbine engine includes a first enclosure with a fuel injector for low-power operation and a primary-oxidizer intake, a second enclosure with a fuel injector for full-power operation and a primary-oxidizer intake, and a third enclosure from which to evacuate burnt gases and which communicates with the first and second enclosures. The wall of the first enclosure includes intake orifices for a dilution oxidizer, but the wall bounding the second enclosure lacks any orifices other than the primary-oxidizer intake orifices.

Abstract: An oxidizer intake flow control system is disclosed for a gas turbine engine combustion chamber. The chamber has an oxidizer intake assembly which extends through the wall of the chamber such that an inlet aperture of the oxidizer intake and an exhaust aperture of the oxidizer intake are located on opposite sides of the wall defining the combustion chamber. An oxidizer intake sleeve defines a central passage through which oxidizer may pass into the combustion chamber. The intake passage extends along a central axis and the intake assembly is attached to the wall of the combustion chamber such that it is rotatable about this central axis. The inlet aperture and/or the exhaust aperture is located in a plane extending non-perpendicularly to the central axis. The combustion chamber may have several oxidizer intake assemblies extending through the combustion chamber walls. The intake assemblies may be interconnected such that they may be simultaneously rotated with respect to the combustion chamber wall.

Abstract: A variable volume combustion chamber for a gas turbine engine that has a able wall to vary the volume of the combustion chamber. The movable wall is positioned according to the operating conditions of the gas turbine engine, achieving one extreme position under idle power and another extreme position under full power. The movement of the wall between the two extreme positions maximizes the efficiency of the combustion chamber for operating conditions between idle and full power. The combustion chamber also restricts at least a portion of the oxidizer intake when the movable wall is positioned for idle power conditions and opens the oxidizer intake when the wall is positioned for maximum power conditions to maximize the flow of oxidizer into the combustion chamber.

Abstract: The present invention relates to a combustion chamber having a counter-flow arrangement in which a first chamber portion mixes the fuel with the primary oxidizer, which mixture is ignited and burned in the first chamber portion. The exhaust gases from the first chamber portion pass into a second chamber portion in which dilution oxidizer air is added to the burned gases. The orientations of the first chamber portion and the second chamber portion are such that the gases pass through the chamber portions in substantially opposite directions, in a counter-flow arrangement. The first chamber portion in which the combustion takes place, provides only primary oxidizer to the fuel mixture, there being no further communication between the interior of the first chamber portion and the oxidizer air supply. This prevents the leaning of the fuel/air mixture in order to reduce the emissions of nitrogen oxide. The mixing of secondary oxidizer air with the exhaust gases takes place solely in the second chamber portion.

Abstract: A combustion chamber wall structure is formed of a plurality of segments, each segment having an upstream portion and a downstream portion. The upstream portion is attached to an outer surface of an adjacent wall segment at its downstream portion in an overlapping fashion such that the overlapping portions form a cooling air chamber. The main cooling air holes are defined by the upstream portion so as to communicate with the cooling chamber, which has an exit to direct the cooling air along an inner surface of the downstream portion of the wall segment. A primary air hole is defined by the downstream portion of the segment and is located adjacent to the main cooling air holes. This location maximizes the distance between the primary air hole and an upstream portion of the same segment, which, in turn, maximizes the distance along the inner surface of the segment on which the cooling air may flow without being disrupted by air passing through the primary air hole.

Abstract: The combustion chamber according to the present invention utilizes a double-walled structure only in the converging portion of the combustion chamber. A hot wall is retained adjacent to, but spaced from a corresponding cold wall so as to provide a cooling space between them. An upstream portion of the hot wall is retained in a notch defined by the cold wall, while the downstream portions each have generally radially extending flanges. Studs pass through openings in the adjacent flanges to prevent any relative circumferential movement, while a clamp serves to attach the flanges to the inlet of a turbine. The clamp slidably retains the flanges therein so as to permit relative radial movement to accommodate any thermal expansion and contraction of the combustion chamber, solely by the appended claims.