Reverse thrust fixing structure

Abstract

The invention relates to a reverse thrust fixing structure, the reverse thrust fixing structure forms the outer wall of a core cabin of an aero-engine, at least one exhaust hole is formed in the reverse thrust fixing structure, the exhaust hole is configured to exhaust airflow in the core cabin, the reverse thrust fixing structure further comprises a one-way valve structure installed on at least one of the exhaust holes, and the one-way valve structure is arranged on the outer wall of the core cabin. The one-way valve structure is configured to increase or decrease an exhaust outlet area of the exhaust vent based on a pressure difference inside and outside the core compartment. The invention further relates to an aero-engine comprising the thrust reverser fixing structure.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of aircraft powerplants, and more particularly to a thrust reverser fixed structure. BACKGROUND

[0002] In a civil aircraft engine, after the fan at the front of the system draws in air, a small portion of the air enters the core engine in the core compartment, while the majority of the air (hereinafter referred to as "main flow air") flows through a shaped passage to the rear end of the system, and this passage through which the airflow passes is called "bypass duct". The outlet section at the end of the bypass duct is called the bypass nozzle, which has a tapered shape for forming an accelerated airflow to generate thrust.

[0003] The aircraft engine includes a thrust reverser fixed structure, which is a fixed component of the bypass nozzle, also known as an inner fixed structure (IFS, or "fixed inner fairing"). Generally speaking, the fairing of the nacelle forms the outer sidewall of the bypass duct, and the IFS forms the inner sidewall of the bypass duct, which mainly provides an efficient aerodynamic surface for the engine bypass exhaust in function, generating thrust.

[0004] Generally, an exhaust annular slot is opened downstream of the bypass fixed structure, specifically between the IFS and the rear fairing of the engine nacelle, for discharging the ventilation cooling airflow in the core compartment of the engine to prevent the accumulation of flammable gas in the core compartment formed by the IFS and the over-temperature in the compartment.

[0005] Generally, the core compartment of the engine can contain the following multiple airflows: 1) compartment ventilation cooling non-dedicated cooling air (passive control), 2) compartment ventilation cooling dedicated cooling air (passive control), 3) aircraft environmental control bleed cooling air (active control), and 4) engine turbine casing cooling air (active control, used as turbine gap control for some models), all of which are from the engine bypass bleed air. Generally, in order to ensure that the exhaust annular slot has sufficient flow capacity, the annular slot area is designed according to the maximum flow.

[0006] However, due to changes in engine operating conditions during actual operation, the actual ventilation cooling flow is significantly less than the maximum design flow in most cases, resulting in excessive ventilation cooling annular slot area during actual operation, which introduces additional resistance. SUMMARY

[0007] In order to solve the problem of additional performance loss of the engine caused by the fixed outlet area of the exhaust annular slot currently used to discharge the ventilation cooling airflow in the core compartment area of the nacelle, the present invention proposes a thrust reverser fixed structure, which adds exhaust holes with variable exhaust area to adjust the cooling exhaust flow rate discharged from the inside of the core compartment, and thus reduces the resistance experienced by the aircraft and makes up for the additional performance loss of the engine.

[0008] In particular, the reverse thrust fixation structure forms an outer wall of a core compartment of an aero-engine, the reverse thrust fixation structure being provided with at least one exhaust hole configured to discharge an airflow inside the core compartment, wherein the reverse thrust fixation structure further comprises a one-way valve structure mounted on at least one of the exhaust holes, the one-way valve structure being configured to increase or decrease an exhaust outlet area of the exhaust hole based on a pressure difference between inside the core compartment and outside the core compartment.

[0009] In one embodiment of the present application, the exhaust hole is provided between an exit portion of an outer bypass nozzle of the aero-engine and an exhaust ring slot.

[0010] In a preferred embodiment of the present application, the exhaust hole is arranged symmetrically around the outer wall of the core compartment to adapt to a symmetric exhaust structure of a nacelle.

[0011] In one embodiment, the one-way valve structure is mounted on each of the exhaust holes.

[0012] Advantageously, the one-way valve structure does not completely close all of the exhaust holes to provide an exhaust outlet under normal conditions.

[0013] In one specific embodiment, the one-way valve structure comprises a valve flap configured to pivot outwardly away from the core compartment or towards the core compartment to increase or decrease the exhaust outlet area of the exhaust hole.

[0014] Advantageously, a seal is provided at the junction of the exhaust hole and the one-way valve structure to prevent leakage of main flow air or core compartment ventilation cooling air through a mounting gap.

[0015] Also advantageously, the one-way valve structure comprises a damper connected between the one-way valve structure and the core compartment to prevent aerodynamic oscillations from introducing additional flow losses and can ensure tight contact between the one-way valve and the seal.

[0016] The present application also relates to an aero-engine comprising the reverse thrust fixation structure as described above.

[0017] The additional features and advantages of the described reverse thrust fixation structure will be set forth in the detailed description which follows, and in part will be apparent from the description or can be learned by the practice of the application as described in the following detailed description and claims, including the detailed description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0018] The technical features of the present application with reference to the above objects are clearly described in the following claims, and the advantages thereof will be apparent from the detailed description below with reference to the attached drawings, which show by way of example the preferred embodiments of the present application, without limiting the scope of the inventive concept.

[0019] Figure 1 A partial schematic view of an aircraft engine is shown.

[0020] Figure 2 A partial schematic view of an aircraft engine is shown, wherein the airflow through the core compartment of the engine is shown.

[0021] Figure 3 A schematic view of a thrust reverser fixation is shown according to an embodiment of the present application.

[0022] Figure 4 An enlarged view of block A in Figure 3 is shown.

[0023] Figure 5 A partial perspective view of an aircraft engine is shown, wherein a thrust reverser fixation according to an embodiment of the present application is shown.

[0024] Reference signs

[0025] 1 thrust reverser fixation

[0026] 2 nacelle shell

[0027] 3 bypass duct

[0028] 4 main flow air

[0029] 5 bypass nozzle

[0030] 6 core engine

[0031] 7 core compartment

[0032] 8 exhaust annulus

[0033] 9 cooled exhaust air

[0034] 11 exhaust hole

[0035] 12 one-way valve structure

[0036] 121 valve flap

[0037] 122 pivot axis

[0038] 13 sealing element

[0039] 14 damping element

[0040] 141 telescopic shaft

[0041] 142 spring element DETAILED DESCRIPTION

[0042] The application will be further described with reference to the drawings and embodiments, but without being limited thereto.

[0043] The term "reverse thrust fixation structure" as used herein is to be understood as an internal fixation structure, IFS, unless otherwise specified.

[0044] The terms "forward end" and "aft end" as used herein are defined according to the flow direction of the airflow in actual flight, specifically, the airflow passes the forward end of the component first and then the aft end of the component.

[0045] The directional terms "outward" and "inward" as used herein refer to a direction away from the component and a direction towards the component, respectively. Further, an "outer wall" refers to a wall on the side further away from the core engine, while an "inner wall" refers to a wall on the side closer to the core engine (cf. Figure 1 ).

[0046] The directional terms "axial" and "circumferential" as used herein refer to a horizontal direction (direction along the central axis of the engine) and a direction around the axial direction, respectively. Figure 1

[0047] The present invention proposes a reverse thrust fixation structure of an aero engine, the reverse thrust fixation structure being configured to form an outer wall of a core compartment of the aero engine, the reverse thrust fixation structure comprising at least one exhaust hole configured to discharge an airflow within the core compartment. The reverse thrust fixation structure further comprises a one-way valve structure mounted on at least one of the exhaust holes, the one-way valve structure being configured to increase or decrease an exhaust outlet area of the exhaust hole based on a pressure difference between the core compartment and outside the core compartment.

[0048] As shown in Figure 1 , the aero engine comprises a reverse thrust fixation structure 1 and a nacelle shell 2, between which an outer duct 3 is formed for the passage of primary flow gases 4 and exit of the primary flow gases from an outer duct nozzle 5. The reverse thrust fixation structure 1 encloses a core engine 6 of the aero engine to form an outer wall of a core compartment 7, at the aft end of which an exhaust annular slot 8 is formed in the reverse thrust fixation structure 1 for the discharge of cooling exhaust gases 9 (i.e. exhaust gases for cooling, or secondary flow).

[0049] Figure 2 The airflow within the core compartment of the engine is shown, in addition to the primary flow gases (i.e. the engine outer duct exhaust gases), the core compartment 7 contains the following airflows: ventilation cooling airflows, engine case leakage airflows, air line leakage airflows, high pressure turbine active clearance control (HPTACC) airflows, and low pressure turbine active clearance control (HPTACC) airflows, etc., which are combined together and discharged from the core compartment 7 as cooling exhaust gases.

[0050] ​The problem with the prior art is that the reverse thrust fixing structure is fixed, which results in the maximum flow allowed to be discharged being designed as a fixed amount, however the flow of various air streams of the cooling exhaust gas will change under different working conditions, which will result in the flow of the cooling exhaust gas changing, and in most cases the actual ventilation cooling flow is significantly less than the maximum design flow, resulting in the ventilation cooling annular gap area being too large during actual operation, which will introduce additional resistance.

[0051] To solve this problem, with reference to Figure 3 , the reverse thrust fixing structure 1 is provided with at least one exhaust hole 11, which is configured to discharge the air stream in the core cabin. Generally, the exhaust hole 11 is provided between the outlet portion of the outer bypass nozzle of the aero-engine and the exhaust annular gap in the axial direction. However, the axial position of the exhaust hole 11 can be determined according to actual needs, and the orientation of the exhaust hole 11 can also be changed, which are all within the scope of the present application.

[0052] It is also preferable that the exhaust holes are arranged symmetrically around the outer wall of the core cabin in the circumferential direction to adapt to the symmetrical structure of the nacelle exhaust. Considering the symmetrical structure of the nacelle exhaust, the number of exhaust holes 11 is even. Further, considering the influence on the structure weight and reliability, in the present embodiment, two exhaust holes 11 are implemented. In other embodiments, the number of exhaust holes 11 can be changed according to actual needs.

[0053] With reference to Figure 3 , the reverse thrust fixing structure further comprises a one-way valve structure 12 installed on at least one of the exhaust holes 11, which is configured to increase or decrease the exhaust outlet area of the exhaust hole 11 based on the pressure difference between the inside and outside of the core cabin 6. It is worth noting that the shape of the exhaust hole 11 can be matched with the installation needs of the one-way valve structure 12, and the number of exhaust holes 11 can be matched with the outflow area of the one-way valve structure 12. In the embodiment of the present application, the one-way valve structure 12 is installed on each of the exhaust holes.

[0054] The design of the exhaust hole 11 and the one-way valve structure 12 makes it unnecessary for the exhaust annular gap to be designed to allow a fixed maximum flow, but can be designed to allow a smaller maximum flow, and once the flow threshold is exceeded, the design of the exhaust hole 11 and the one-way valve structure 12 can be adjusted to allow an amount of exhaust gas to be discharged beyond the flow threshold.

[0055] Advantageously, the one-way valve structure 12 does not completely close the exhaust hole 11 to provide an exhaust outlet under normal conditions. Of course, if necessary, the one-way valve structure 12 can also be designed to completely close the exhaust hole 11 under certain working conditions. This is also within the scope of the present application.

[0056] With reference to Figure 3 and 4In one embodiment, the one-way valve structure 12 comprises a valve flap 121 and a pivot shaft 122, the pivot shaft 122 is configured to be positioned at the rear end of the reverse thrust fixing structure 1, and the valve flap 121 is configured to be pivoted outward away from the core cabin 7 or inward toward the core cabin 7 around the pivot shaft 122 to increase or decrease the exhaust outlet area of the exhaust hole 11.

[0057] Advantageously, the shape of the valve flap 121 can be square or sector-shaped, so that the opening pressure of the valve flap 121 (i.e. the pressure that forces it to pivot outward) matches the cabin pressure difference with the main flow pressure under the large flow demand of the ventilation cooling exhaust.

[0058] As can be seen from the figure, the one-way valve structure 12 covers the exhaust hole 11, so that the exhaust outlet is located downstream of the one-way valve structure 12, and thus the position of the exhaust leaving the core cabin 7 can be changed by modifying the shape of the one-way valve structure 12. Further, the contact position of the exhaust outlet with the main flow gas can be set to be circular arc-shaped, zigzag-shaped or other shapes that are advantageous for improving exhaust efficiency and reducing exhaust noise.

[0059] Referring to Figure 5 , a seal 13 can be provided at the junction of the exhaust hole 11 and the one-way valve structure 12 to prevent leakage of the main flow air (see Figure 1 ) or the core cabin ventilation cooling gas through the installation gap.

[0060] Referring back to Figure 4 , the one-way valve structure 12 comprises a damping member 14 connected between the one-way valve structure 12 and the core cabin, specifically between the one-way valve structure 12 and the inner wall of the core cabin 7, to prevent the introduction of additional flow loss by aerodynamic oscillation.

[0061] In one embodiment, the damping member 14 comprises a telescopic shaft 141 hinged between the one-way valve structure 12 and the inner wall of the core cabin 7, and a spring element 142, which can be a tension spring, is sleeved outside the telescopic shaft 141. In this way, the damping member can cope with sudden changes in pressure difference and ensure close contact between the one-way valve structure 12 and the seal (see Figure 5 ). It should be understood that the configuration of the damping member is not fixed, but can have other various configurations.

[0062] The present application introduces a one-way valve into the exhaust fixing structure, realizes the self-adaptive change of the ventilation cooling exhaust area with the cooling gas flow, reduces the design matching difficulty of the outer duct nozzle exhaust area and the ventilation cooling exhaust area, improves the flow matching capability of the exhaust system under different bleed air demand conditions, and also reduces the additional resistance introduced by the excessive design of the exhaust ring gap, thereby improving the exhaust efficiency.

[0063] Although the above has been described with respect to the preferred embodiments of the present application, it will be recognized by those of ordinary skill in the art that modifications and variations can be made to the present application without departing from the scope or spirit of the application. Accordingly, it should be understood that the present application is not limited to the preferred embodiments described above.

Claims

1. A thrust reverser fixing structure, wherein the thrust reverser fixing structure forms the outer wall of the core compartment of an aero-engine, wherein, The thrust reverser fixing structure has at least one exhaust port, which is configured to discharge airflow from the core compartment. The thrust reverser fixing structure further includes a one-way valve structure installed on at least one of the exhaust ports, the one-way valve structure being configured to increase or decrease the exhaust outlet area of ​​the exhaust port based on the pressure difference between the inside and outside of the core compartment.

2. The reverse-pushing fixing structure as described in claim 1, characterized in that, The exhaust port is located between the outlet portion of the outer bypass nozzle of the aero-engine and the exhaust ring gap.

3. The reverse-pushing fixing structure as described in claim 1, characterized in that, The exhaust vents are arranged symmetrically around the outer wall of the core compartment.

4. The reverse-pushing fixing structure as described in claim 1, characterized in that, The one-way valve structure is installed on each of the exhaust ports.

5. The reverse-pushing fixing structure as described in claim 1, characterized in that, The one-way valve structure does not completely seal all of the exhaust ports.

6. The reverse-pushing fixing structure as described in claim 1, characterized in that, The one-way valve structure includes a valve plate configured to pivot outward from the core compartment or inward toward the core compartment to increase or decrease the exhaust outlet area of ​​the exhaust port.

7. The reverse-pushing fixing structure as described in claim 1, characterized in that, A seal is provided at the junction of the vent and the one-way valve structure.

8. The reverse-pushing fixing structure as described in claim 1, characterized in that, The one-way valve structure includes a damping element, which is connected between the one-way valve structure and the core compartment.

9. An aircraft engine comprising a fixed thrust reverser structure as described in any one of claims 1-8.

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