Societe Nationale D'etude Et De Construction De Moteurs D'aviation

Patrice A Commaret

Michel A Desaulty

Denis J Sandelis

Denis R Ansart

Gerard M Mandet

Rodolphe Martinez

Didier H Hernandez

Eric J Lancelot

Patrick, S Ciccia

Etienne S David

Bruno M Quinquenneau

Jean-Claude Laugeois

A fuel injection assembly for a combustion chamber of a gas turbine engine is disclosed in which a plurality of premixing chambers are in communication with the combustion chamber and adjacent pairs of the premixing chambers are connected to a single prevapoization chamber by prevaporization conduits. Fuel is injected into the prevaporization chamber via a fuel injector and is mixed with oxidizer passing into the prevaporization chamber such that the fuel/oxidizer mixture has a richness exceeding the stoichiometric ratio. The fuel/oxidizer mixture passes into the prevaporization conduits through a diaphragm opening and, upon entering the premixing chamber, is mixed with additional oxidizer such that the fuel/oxidizer mixture in each premixing chamber has a richness less than the stoichiometric ratio. The premixing chambers are bounded by generally tubular walls, a portion of each adjacent tubular wall forming a protective hood between the fuel injector and the combustion chamber so as to prevent self-ignition of the fuel/oxidizer mixture in the prevaporization chamber. Oxidizer entering the premixing chambers passes through one or more oxidizer swirlers to assure a complete mixing of the fuel and oxidizer prior to its passing into the combustion chamber.

Fuel injection assembly for a gas turbine engine

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. The outer wall has a plurality of cooling holes to enable cooling air to pass through the outer wall into cooling contact with the inner wall. The frusto-conical chamber has a downstream evacuation passage to allow cooling air to pass from the frusto-conical chamber.

Pre-mixing injection system for a turbojet engine

A combustion chamber structure wherein the combustion chamber extends around a central, longitudinal axis and has primary oxidizer intake passageways whose positions along the central axis relative to an end of the combustion chamber are adjustable depending upon the operating conditions of the gas turbine engine. By controlling axial positions of the primary oxidizer intake passageways, the dwell time of the combustion gases and primary oxidizer inside the combustion zone of the chamber may also be controlled so as to increase the stability of the combustion, while at the same time minimizing the polluting emissions. The invention also encompasses the concept of adjusting the cross-sectional area of the primary oxidizer intake passageways as their positions along the central axis are adjusted. This enables a more accurate control of the volume of the primary oxidizer flow in addition to controlling the location of the flow.

Gas turbine combustion chamber with adjustable primary oxidizer intake

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.

Turbojet engine combustion chamber with a double wall converging zone

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Maincy, France

Patrice A Commaret