Discharge device for an aircraft turbomachine with at least two flows.

Abstract

The present invention relates to a discharge device (3, 3') for an aircraft turbomachine with at least two flows, comprising a discharge conduit (4) for an airflow having an inlet (41) and an outlet (42).This device is remarkable in that it comprises an inner ferrule segment (5), an outer ferrule segment (6) and a structural arm (8) fixed between the two, in that this arm (8) comprises two lateral sides (81, 82), which together with the two ferrule segments (5, 6) define an inner space (84) of the arm (8), at least one of the two sides being pierced with a lateral air extraction opening (810), which opens into said inner space (84), in that the inner ferrule segment (5) is pierced with an air extraction orifice (50) opening into said inner space (84) and in that the air outlet (42) is connected to the air extraction orifice (50), so as to put the air inlet (41) into air communication with said lateral air extraction opening (810). Figure for the summary: Fig. 3.

Description

Title of the invention: Discharge device for an aircraft turbomachine with at least two flows. FIELD OF INVENTION

[0001] The invention is in the field of aircraft turbomachinery with at least two flows and more specifically in the field of discharge devices which allow the pressure to drop downstream of the low pressure compressor of such turbomachinery.

[0002] The present invention relates more particularly to a discharge device for an aircraft turbomachine with at least two flows and to an aircraft turbomachine with at least two flows, equipped with such a discharge device.

[0003] Turbomachines with at least two flows refer in particular more specifically to turbomachines known as "double flow turbomachine" or "triple flow turbomachine". STATE OF THE ART

[0004] In the attached [Fig. 1], a diagram of a double-flow turbomachine 1 with longitudinal central axis X-X' can be seen. In the remainder of the description and claims, the terms "radially internal" and "radially external" refer to the radial position of an element with respect to this axis.

[0005] In a conventional manner, this turbomachine comprises, from upstream to downstream, with respect to the direction of flow of air and gases in the turbomachine, a shrouded blower 10 called a "fan", a low-pressure compressor 11, a high-pressure compressor 12, a combustion chamber 13, a high-pressure turbine 14 and a low-pressure turbine 15.

[0006] The compressors 11 and 12, the combustion chamber 13 and the turbines 14 and 15 are housed in an internal casing 16 with a central axis X-X' and together form a gas generator 160. This internal casing 16 thus delimits a first air flow channel 161.

[0007] An external casing 100 or nacelle surrounds the blower 10 and the gas generator 160 and delimits, together with the internal casing 16, a second air flow channel 101.

[0008] Several structural arms 17 connect the radially external face 162 of the inner housing 16 to the radially internal face 102 of the outer housing 100. These arms 17 extend radially with respect to the axis X-X' and are therefore arranged across the second airflow channel 101.

[0009] The air (flow F) drawn in by the blower 10 is divided between a primary airflow I, which flows in the first air flow channel 161 of the gas generator 160 and a secondary airflow II, which flows in the second air flow channel 101, which surrounds the gas generator. The two concentric flows meet downstream at the turbomachine's exhaust nozzle.

[0010] Moreover, such a turbomachine generally includes a discharge device which makes it possible to avoid the phenomenon of pumping or stalling of the low pressure compressor 11.

[0011] In a compressor in general, and more specifically in the low pressure compressor 11, the air is compressed so that it exits the compressor at a higher pressure than the inlet pressure.

[0012] However, similarly to an aircraft wing which can lose lift and "stall" when it is at a high angle of attack and the aircraft is at low speed, a compressor can undergo a similar phenomenon.

[0013] Thus, at reduced flow rate, the compressor no longer pushes the airflow downstream, and the high-pressure air downstream of the compressor empties towards the compressor inlet, which is at a lower pressure. A reversal of the airflow direction may even occur. Once sufficient air discharge has occurred, the compressor can return to normal operating conditions and restore the airflow in the correct direction (upstream to downstream).

[0014] Such cyclic flow fluctuations are called “pumping”.

[0015] Such a phenomenon can however be destructive to the compressor blades and cause their destruction or at the very least cause vibrations in them.

[0016] In order to avoid these problems, it is known to install at least one discharge device 2, downstream of the low pressure compressor 11 and upstream of the high pressure compressor 12.

[0017] This discharge device 2 includes an air discharge conduit 20, configured to be connected to a discharge valve 163, known by the English acronym VBV (for "Variable Bleed Valve") or by the French acronym VDV (for "Vanne de déboudre variable"). This discharge valve 163 is positioned in the first air flow channel 161.

[0018] The radially internal end (or inlet 201) of the air discharge duct 20 opens into the first air flow channel 161 and the radially external end (or outlet 202) of this same duct opens into the second air flow channel 101. The discharge valve 163 is installed at the radially internal end of the duct 20.

[0019] The discharge device 2 thus makes it possible, in situations of reduced flow rates and by controlling the opening or closing of the discharge valve 163, to be able to draw or not take air downstream of the low pressure compressor 11 and to drop the pressure there, so as to avoid backflow and therefore pumping of the compressor.

[0020] However, depending on the type of gas generator, integration problems with the discharge device within the turbomachine can sometimes arise due to space constraints. For example, as shown in [Fig. 1], the outlet 202 of an air discharge duct 20 may be located at the leading edge of a structural arm 17. This particular positioning is problematic because the presence of the arm 17 in the second airflow channel 101 creates a stagnation point and thus a rise in static pressure near the outlet 202. The discharge device then no longer performs its function, and again, a pumping phenomenon of the low-pressure compressor 11 is likely to occur.

[0021] Currently, the only known solution to resolve this problem is to arrange the air discharge duct 20 so that its outlet 202 is not located in the azimuthal zone "obstructed" by the structural arm 17.

[0022] However, in some cases, integration constraints do not allow the outlet mouth 202 to be offset azimutally to avoid the upper pressure zone located in front of the arm 17.

[0023] Moreover, such an arrangement can prove costly due to the complex geometry that must then be given to the air discharge duct 20 and can lead to a significant pressure loss due to the changes in direction imposed on the air in this modified duct.

[0024] The same problems can be encountered with a triple-flow turbomachine.

[0025] On the attached [Fig.2], a diagram of a triple-flow turbomachine 1' with central axis X-X' can be seen.

[0026] This turbomachine 1' has identical elements to those of the double-flow turbomachine, which will not be described again in detail and which bear the same numerical references.

[0027] The triple-flow turbomachine 1' differs from the double-flow turbomachine 1 in that it includes an intermediate casing 18, with a central axis X-X', radially interposed between the inner casing 16 and the outer casing 100.

[0028] The turbomachine 1' thus comprises a first air flow channel 161 of the gas generator 160, provided as described in connection with the turbomachine 1, between the inner casing 16 and the central axis X-X', a second air flow channel 181, provided between the inner casing 16 and the intermediate casing 18 and a third air flow channel 103, provided between the intermediate casing 18 and the outer casing 100.

[0029] With this architecture, the air (flow F) drawn in by the blower 10 is divided between a primary airflow I (radially internal), which flows in the first airflow channel 161, and a secondary airflow II, which flows in the third channel air flow 103 and a tertiary air flow III, which circulates in the second air flow channel 181.

[0030] As previously explained for the double-flow turbomachine 1, pumping phenomena of the low-pressure compressor 11 can also occur in the triple-flow turbomachine 1'.

[0031] Consequently, it would also be advantageous to provide a discharge device, downstream of the low-pressure compressor 11, allowing air to be discharged between the first air flow channel 161 and the second air flow channel 181. Description of the invention

[0032] The invention therefore aims to maintain the efficiency of the discharge device in the flow of the low pressure compressor, despite the presence of a structural arm in the second air circulation channel, in which the secondary flow circulates in the case of a double-flow turbomachine or the tertiary flow in the case of a triple-flow turbomachine, and this despite the fact that this arm generates a pressure rise at the level of its leading edge, which is detrimental to the aerodynamic behavior of this discharge device.

[0033] For this purpose, the invention relates to a discharge device for an aircraft turbomachine with at least two flows, comprising a first discharge conduit for an air flow, which includes an air inlet and an air outlet.

[0034] According to the invention, this discharge device comprises an inner ferrule segment and an outer ferrule segment, which define between them an airflow channel; it comprises a structural arm fixed between said inner ferrule segment and said outer ferrule segment; this structural arm comprises two lateral sides, which, together with the inner ferrule segment and the outer ferrule segment, define an internal space of the arm; at least one of the two lateral sides of the structural arm is pierced with a first lateral air extraction opening, which opens into said internal space of the arm; the inner ferrule segment is pierced with an air extraction orifice, which also opens into said internal space of the arm; the air inlet of the first discharge duct is configured so as to be able to be connected to a discharge valve of the turbomachine,and the air outlet of the first discharge duct is connected to the air extraction port, so as to establish an air supply between the air inlet of the first discharge duct and said first lateral air extraction opening.

[0035] Thanks to these features of the invention, a primary airflow entering the discharge duct of the discharge device emerges on the lateral side of the structural arm, and can then flow into the airflow channel downstream of the arm, without disturbing the airflow arriving upstream of the arm, at the edge attack of the latter, and without creating air turbulence. In other words, the airflow flows in a lateral area of ​​the structural arm not subjected to the increase in static pressure that exists at the leading edge of this arm.

[0036] According to other advantageous and non-limiting features of the invention, taken alone or in combination:

[0037] -the discharge device includes a second discharge duct for an airflow, this second discharge duct having an air inlet and an air outlet, at least the other of the two lateral sides of the structural arm is pierced by a second lateral air extraction opening, which opens into said internal space of the arm, the air inlet of the second discharge duct is configured to be able to be connected to a discharge valve of the turbomachine and the air outlet of the second discharge duct is connected to the air extraction orifice, so as to put in air communication the air inlet of the second discharge duct with said second lateral air extraction opening.

[0038] -the inner ferrule segment includes at least one fixing lug, configured to allow the fixing of this inner ferrule segment on a radially internal wall of a second airflow channel of the turbomachine.

[0039] -the outer ferrule segment includes at least one fixing flange, configured to allow the fixing of this outer ferrule segment on a radially external wall of a second airflow channel of the turbomachine.

[0040] -the first discharge conduit comprises a radially external wall, a radially internal wall and two side walls, one of the side walls having a notch at its upper part and the first discharge conduit is positioned in the structural arm, so that the radially external edges respectively of the radially external wall, of the other of the two side walls and of the radially internal wall are fixed in a gas-tight manner to the external ferrule segment and that the notch is opposite the first lateral air extraction opening.

[0041] -the second discharge conduit comprises an external radial wall, an internal radial wall and two side walls, one of the side walls having a notch at its upper part, and the second discharge conduit is positioned in the structural arm, so that the external radial edges respectively of the external radial wall, of the other of the two side walls and of the internal radial wall are fixed in a gas-tight manner to the external ferrule segment and that the notch of the side wall is opposite the second lateral air extraction opening.

[0042] The invention also relates to an aircraft turbomachine with at least two flows, comprising a first airflow channel and a second flow channel air, a low pressure compressor and a high pressure compressor arranged in said first air flow channel, the turbomachine also comprising at least one relief valve, mounted in the first air flow channel between the low pressure compressor and the high pressure compressor.

[0043] In accordance with the invention, this turbomachine comprises at least one discharge device as above, the air inlet of said first discharge duct of an airflow is connected to said at least one discharge valve, the air inlet of said second discharge duct of an airflow, if the latter is present, is connected to said at least one discharge valve, and said inner shell segment and said outer shell segment are connected respectively to the radially inner wall and to the radially outer wall of said second airflow channel, so that said first lateral air extraction opening of the structural arm and said second lateral air extraction opening, if the second discharge duct of an airflow is present, open into said second airflow channel.

[0044] According to other advantageous and non-limiting features of the invention:

[0045] - this turbomachine is a double-flow turbomachine and said second channel The airflow channel is a channel through which the secondary airflow II flows.

[0046] - this turbomachine is a triple-flow turbomachine and said second channel air flow is a channel in which the tertiary air flow III circulates. DESCRIPTION OF THE FIGURES

[0047] Other features, objectives and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0048] The [Fig. 1] is a diagram representing a double-flow turbomachine.

[0049] Fig. 2 is a diagram representing a triple-flow turbomachine.

[0050] Figure 3 is a perspective view of a first embodiment of the device discharge according to the invention.

[0051] Fig. 4 is a perspective view of a second embodiment of the discharge device according to the invention.

[0052] The [Fig.5] is a partial cross-sectional view of the discharge device of the [Fig.4], taken along the cutting line VV on the [Fig.4].

[0053] Fig. 6 is a perspective view of the discharge conduit of the discharge device according to Fig. 3. DETAILED DESCRIPTION OF THE INVENTION

[0054] A first embodiment of the discharge device according to the invention and referenced 3 will now be described in connection with [Fig.3].

[0055] Generally, the discharge device 3 comprises an airflow discharge conduit 4, referred to as the "first discharge conduit", an inner ferrule segment 5 and an outer ferrule segment 6, which delimit between them an airflow channel 7, and a structural arm 8, fixed between said inner ferrule segment 5 and said outer ferrule segment 6.

[0056] In the double-flow turbomachine 1 of [Fig. 1], the discharge device 3 is intended to replace the prior art discharge device 2. In other words, the duct 4 replaces the duct 20 and the structural arm 8 replaces the structural arm 17.

[0057] In the triple-flow turbomachine 1' of [Fig.2], the discharge device 3 according to the invention has been shown in the place it occupies.

[0058] It should also be noted that it is possible to have several discharge devices according to the invention, distributed at several points on the circumference of the first channel 161.

[0059] The discharge device 3 has a longitudinal axis Xl-X' 1.

[0060] The discharge conduit 4 includes, at both ends, an air inlet 41 and an air outlet 42.

[0061] The discharge duct 4 is advantageously angled to allow connection between the first airflow channel 161 and the second airflow channel 101, 181, which is located radially further outward than the first channel. Preferably, the cross-section of the air inlet 41 and the cross-section of the air outlet 42 extend in two planes perpendicular to each other.

[0062] Preferably, this air inlet 41 has a rectangular or substantially rectangular cross-section.

[0063] The air inlet 41 of said first discharge duct 4 is configured to be able to be connected to the discharge valve VDV 163 of the turbomachine 1 or 1', so that the opening of the valve 163 allows air to be drawn downstream of the low pressure compressor 11 to be introduced into the duct 4 and the closing of this valve interrupts this air circulation.

[0064] The inner ferrule segment 5 and the outer ferrule segment 6 are each in the form of a plate, the contour of which is preferably square or rectangular or substantially square or rectangular. This plate is preferably slightly curved, so that its concavity is oriented towards the conduit 4 and that when the discharge device is in place in the turbomachine 1, 1', its concavity is oriented radially towards the central axis X-X' of the turbomachine.

[0065] The inner ferrule segment 5 is pierced with an air extraction orifice 50, preferably located in its central part.

[0066] Preferably, the outer ferrule segment 6 includes at least one fixing flange 61 which allows the fixing of this segment 6 on the radially external wall of the second air flow channel 101, 181.

[0067] If the turbomachine is a dual-flow 1, then this radially external wall of the second airflow channel 101 is the radially internal face 102 of the external casing 100. If the turbomachine is a triple-flow 1', then this radially external wall of the second airflow channel 181 of the turbomachine 1 is the radially internal face 182 of the intermediate casing 18.

[0068] Preferably, the outer ferrule segment 6 comprises two fixing flanges 61, 62 located on either side, as shown in [Fig.4].

[0069] Preferably, this mounting flange 61 extends axially (along the Xl-X' 1 axis) and has, for example, the shape of an L-shaped profile, as can be seen in the figures. The shape and dimensions of this flange 61 are adapted according to the shape and dimensions of the radially external wall of the second airflow channel 101, 181 to which it is to be fixed.

[0070] Preferably, the inner ferrule segment 5 includes at least one fixing tab 51 which allows the fixing of this segment 5 on the radially internal wall of the second air flow channel 101, 181.

[0071] Whether the turbomachine is double or triple flow, this radially internal wall of the second air flow channel 101, 181 is the radially external face 162 of the internal casing 16 of the turbomachine 1 or 1'.

[0072] Preferably, the inner ferrule segment 5 comprises two fixing tabs 51, 52 located on either side, as shown in [Fig.4].

[0073] Preferably, this mounting bracket 51 extends axially (along the XI-X' 1 axis) and, for example, has the shape of an elongated profile with several portions of different inclinations, as can be seen in the figures. The shape and dimensions of this mounting bracket 51 are adapted according to the shape and dimensions of the inner wall of the second airflow channel 101, 181 to which it is to be attached.

[0074] Once the inner ferrule segment 5 and the outer ferrule segment 6 are fixed respectively to the radially inner wall and the radially outer wall of the second airflow channel, the airflow channel 7 of the device 3 constitutes a portion of this second airflow channel 101, 181.

[0075] The structural arm 8 ensures the relative positioning of the inner ferrule segment 5 with respect to the outer ferrule segment 6.

[0076] This structural arm 8 comprises two opposing radial lateral flanks 81 and 82 (see [Fig. 4]). They are curved and meet upstream (with respect to the direction of air circulation in channel 7) at the level of a leading edge 83. They meet downstream at the level of a trailing edge (not visible in the figures).

[0077] These two lateral sides 81 and 82 delimit with the internal ferrule segment 5 and the external ferrule segment 6, an internal space 84 of the arm.

[0078] At least one of the two lateral sides 81 and 82 (for example side 81 in [Fig.3]) is pierced with a first lateral air extraction opening 810, which opens into said internal space 84 of the arm 8 (and also into the channel 7).

[0079] In addition, the air extraction orifice 50 formed in the internal ferrule segment 5 also opens into the internal space 84 of the arm 8.

[0080] Furthermore, the air outlet 42 of the duct 4 is also connected to the air extraction orifice 50.

[0081] By referring to figures 3 and 6, it can be seen that the discharge conduit 4, which here has a rectangular cross-section, comprises a radially external wall 43 concave, a radially internal wall 44 convex and two lateral walls 45 and 46.

[0082] The lateral wall 45 is the one which is located in the extension of the flank 81 of the arm 8. This lateral wall 45 has at its upper part (or radially external part) a notch 450. The lateral wall 46 does not have one.

[0083] Preferably, the discharge conduit 4 is positioned in the structural arm 8, so that the upper (or radially external) edges 430 of the wall 43, 460 of the wall 46 and 440 of the wall 44 are fixed in a gas-tight manner (preferably welded) to the external ferrule segment 6, and that the notch 450 is opposite the first lateral air extraction opening 810.

[0084] The operation of the discharge device 3 is as follows:

[0085] When the discharge valve 163 is opened, the primary airflow I enters in the air inlet 41, goes up into the discharge duct 4, passes through the notch 450 and the first lateral air extraction opening 810 to open into the air flow channel 7. Thus, the air inlet 41 is in air communication with said opening 810.

[0086] However, thanks to this structural arrangement, the air from the primary flow I enters the airflow channel 7 but in the downstream part of the structural arm 8, that is to say, at a point far from its leading edge 83. Thus, the air from the primary flow I exiting the discharge duct 4 does not disturb the flow of the secondary air flow II or tertiary air flow III circulating in the second airflow channel 101, 181.

[0087] A second embodiment of the discharge device according to the invention and referenced 3' will now be described in connection with figures 4 and 5.

[0088] This discharge device 3' differs from device 3 in that it includes a second discharge conduit 4', arranged next to the first discharge conduit 4.

[0089] Preferably, this discharge device 3' has a plane of symmetry P passing through the leading edge 83 of the structural arm 8 and through its trailing edge. The two conduits 4 and 4' are arranged on either side of this plane of symmetry P. The second conduit 4' is the mirror image of the first conduit 4 with respect to this plane of symmetry P.

[0090] The elements common with the discharge device 3 will not be described again in detail and bear the same numerical references.

[0091] The second discharge duct 4' includes an air inlet 41', an air outlet 42', a concave radially external wall 43', a convex radially internal wall 44' and two side walls 45' and 46'.

[0092] The side wall 45' is located in the extension of the side 82 of the arm 8. The side wall 82 of the arm 8 is pierced by a second lateral air extraction opening 820, which opens into said internal space 84 of the arm 8 and into the channel 7.

[0093] The side wall 45' has a notch 450' at its upper part. The side wall 46' does not have one.

[0094] Furthermore, the air outlet 42' of the second discharge duct 4' is also connected to the air extraction port 50.

[0095] Preferably, the second discharge conduit 4' is positioned in the structural arm 8, so that the upper (or radially external) edges 430' of the wall 43', 460' of the wall 46' and 440' of the wall 44 are fixed in a gas-tight manner (preferably welded) to the external ferrule segment 6, and the notch 450' is opposite the second lateral air extraction opening 820.

[0096] Finally, the air inlet 41' is configured to be able to be connected to the discharge valve 163.

[0097] Thanks to this architecture, the air inlet 41' of the second discharge duct 4' is in air communication with the second lateral air extraction opening 820, with the same beneficial effects as those previously explained in connection with the first discharge duct 4.

Claims

Demands

1. Discharge device (3, 3') for an aircraft turbomachine (1, 1') with at least two streams, comprising a first discharge duct (4) for an air stream, which has an air inlet (41) and an air outlet (42), characterized in that it comprises an inner ferrule segment (5) and an outer ferrule segment (6), which delimit between them an airflow channel (7), in that it comprises a structural arm (8) fixed between said inner ferrule segment (5) and said outer ferrule segment (6), in that this structural arm (8) comprises two lateral sides (81, 82), which, together with the inner ferrule segment (5) and the outer ferrule segment (6), delimit an internal space (84) of the arm (8), in that at least one (81) of the two lateral sides (81, 82) of the structural arm (8) is pierced by a first lateral air extraction opening (810), which opens into said internal space (84) of the arm,in that the inner ferrule segment (5) is pierced with an air extraction orifice (50), which also opens into said internal space (84) of the arm (8), in that the air inlet (41) of the first discharge duct (4) is configured to be able to be connected to a discharge valve of the turbomachine (1, 1'), and in that the air outlet (42) of the first discharge duct (4) is connected to the air extraction orifice (50), so as to establish air communication between the air inlet (41) of the first discharge duct (4) and said first lateral air extraction opening (810).

2. Discharge device (3, 3') according to claim 1, characterized in that it comprises a second discharge duct (4') for an airflow, this second discharge duct (4') having an air inlet (41') and an air outlet (42'), in that at least the other (82) of the two lateral sides (81, 82) of the structural arm (8) is pierced by a second lateral air extraction opening (820), which opens into said internal space (84) of the arm (8), in that the air inlet (41') of the second discharge duct (4') is configured to be able to be connected to a discharge valve of the turbomachine (1, 1'), and in that the air outlet (42') of the second discharge duct (4') is connected to the air extraction orifice (50), so as to put in air communication the air inlet (41') of the second discharge duct (4') with said second lateral air extraction opening (820).

3. Discharge device (3, 3') according to claim 1 or 2, characterized in that the inner ferrule segment (5) comprises at least one fixing tab (51, 52), configured to allow the fixing of this inner ferrule segment (5) to a radially internal wall of a second airflow channel of the turbomachine (1, 1')-

4. Discharge device (3, 3') according to any one of the preceding claims, characterized in that the outer ferrule segment (6) comprises at least one fixing flange (61, 62), configured to allow the fixing of this outer ferrule segment (6) on a radially external wall of a second airflow channel of the turbomachine (1, 1').

5. Discharge device (3, 3') according to any one of the preceding claims, characterized in that the first discharge conduit (4) comprises a radially external wall (43), a radially internal wall (44) and two side walls (45, 46), -in that one of the side walls (45) has a notch (450) at its upper part, -and in that the first discharge conduit (4) is positioned in the structural arm (8), so that the radially external edges (430, 460, 440) respectively of the radially external wall (43), of the other of the two side walls (46) and of the radially internal wall (44) are fixed in a gas-tight manner to the external ferrule segment (6) and that the notch (450) is opposite the first lateral air extraction opening (810).

6. Discharge device (3, 3') according to claim 2 or according to claim 2 and any one of the preceding claims, characterized in that the second discharge conduit (4') comprises a radially external wall (43'), a radially internal wall (44') and two lateral walls (45', 46'),

7.

8. -in that one of the side walls (45') has a notch (450') at its upper part, -and in that the second discharge conduit (4') is positioned in the structural arm (8), so that the radially external edges (430', 460', 440') respectively of the radially external wall (43'), of the other of the two side walls (46') and of the radially internal wall (44') are fixed in a gas-tight manner to the external ferrule segment (6) and that the notch (450') of the side wall (45') is opposite the second lateral air extraction opening (820). Aircraft turbomachine (1, 1') with at least two flows, comprising a first airflow channel (161) and a second airflow channel (101, 181), a low-pressure compressor (11) and a high-pressure compressor (12) disposed in said first airflow channel (161), the turbomachine (1, 1') also comprising at least one relief valve (163), mounted in the first airflow channel (161) between the low-pressure compressor (11) and the high-pressure compressor (12), characterized in that it comprises at least one relief device (3, 3') according to any one of the preceding claims, in that the air inlet (41) of said first airflow relief duct (4) is connected to said at least one relief valve, in that the air inlet (41') of said second airflow relief duct (4') if the latter is present, at least one discharge valve (163) is connected to saidand in that said inner ferrule segment (5) and said outer ferrule segment (6) are connected respectively to the radially inner wall and the radially outer wall of said second airflow channel (101, 181), such that said first lateral air extraction opening (810) of the structural arm (8) and said second lateral air extraction opening (820), if the second airflow discharge duct (4') is present, open into said second airflow channel (101, 181). Aircraft turbomachine according to claim 7, characterized in that this turbomachine is a twin-spool turbomachine (1) and in,

9. that said second airflow channel is a channel (101) in which the secondary airflow (II) flows. Aircraft turbomachine according to claim 7, characterized in that this turbomachine is a triple-flow turbomachine (1') and in that said second airflow channel is a channel (181) in which the tertiary airflow flows.

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