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

Michel S Guimier

Philippe M Paris

Patrick R Derouet

Patrick Kapala

A self regulating bleed valve for a gas turbine engine is provided which taps or bleeds a portion of a gas, typically air, from a duct of the gas turbine having a wall bounding the gas flow. The bleed valve has a valve member pivotally attached to the wall such that the valve member extends through a main opening formed in the wall. The valve member has an internal cavity in communication with a gas inlet opening and a gas exhaust opening and is pivotally movable between an extended position wherein the gas inlet opening portion of the valve member extends into the gas flow duct such that the inlet opening faces generally in an upstream direction so as to deflect a portion of gas flow into the internal cavity, and a retracted position wherein the inlet opening extends obliquely, generally parallel, to the gas flow so as to minimize the air tapped or bled from the gas flow. The bleed valve also includes a control device fixedly attached to the valve member which is acted on by the flow of gas to cause the valve member to pivot between its extended and retracted positions, depending upon the speed and pressure of the gas flow. Thus, the self-regulating bleed valve taps or bleeds a generally constant amount of air regardless of the speed or pressure of the gas flow with which the valve is associated.

Self regulating bleed valve

The system makes it possible to reduce the clearances existing between the rotor and stator of a turbine (40) of a turbo jet engine during the various operating phases of the latter whilst keeping the temperatures of the disks inside the limits of their mechanical behaviour. The disks (4) of the turbine (40) are ventilated via the sampling of high pressure air at a high temperature (2) and the stator via the sampling of low pressure air at a low temperature (3). The respective temperatures of these two samplings are homogenized by a heat exchanger (1). This exchanger is short-circuited by a branch circuit connection (5) on the low pressure circuit so as to keep as stable as possible the clearances inside the turbine (40) according to the various ranges of capacity of the turbo jet engine by means of a valve (6) controlled by the computer. Application for aircraft turbo jet engines.

System for ventilating the turbine disks and stator of a turbo jet engine

A unitary exhaust gas housing for a turbo-engine comprises an outer ring, two intermediate rings defining the flow path for the hot gases, and an inner ring forming a hub with a hollow annular chamber. A temperature control device is provided including a bleed tube having one end fixed and communicating with the gas flow path for drawing off hot gases therefrom, the other end of the tube passing into the hollow chamber of the hub where it regulates the flow of gases by variation of the clearance j between the end of the tube and the opposing wall of the hub in response to relative radial movements of the tube and the hub according to the thermal states of the assembly.

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Mormani, France

Michel S Guimier