Aircraft engine fan inlet structure and aircraft comprising same

Abstract

An aircraft engine fan inlet structure for introducing airflow from within an engine outer bypass duct to a downstream air supply system, the structure comprising: first and second inlet ports provided on a surface of a fairing disposed within the engine outer bypass duct; a first inlet passage in communication with the first inlet port and extending downstream from the first inlet port; a second inlet passage in communication with the second inlet port and extending downstream from the second inlet port; and a main inlet passage directly communicating with both the first and second inlet passages downstream of the first and second inlet passages and configured such that the first inlet port is able to communicate with the second inlet port via the first inlet passage, the main inlet passage and the second inlet passage in that order. The structure advantageously eliminates pressure fluctuations occurring within the fan inlet system, reduces the impact on the outer bypass flow field while maintaining its own efficiency, and is easy to manufacture, assemble and install.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft design and manufacturing, more particularly to the field of aircraft engine design and manufacturing, and particularly to a fan inlet structure of an aircraft engine and an aircraft comprising the same. BACKGROUND

[0002] In an aircraft system, especially a civil aircraft system, the engine needs to provide air source for the air source system of the aircraft, which is used for the downstream air using system, including but not limited to air conditioning system, anti-icing system, etc.

[0003] Generally, since the gas drawn from the engine compressor is high-temperature and high-pressure gas, it is usually necessary to cool this part of high-temperature and high-pressure gas by introducing low-temperature gas from the engine bypass duct using a heat exchanger to meet the requirements of the air source system. The cold side passage gas of the heat exchanger can be introduced laterally relative to the main flow direction of the bypass duct by the fan inlet, enters the heat exchanger after passing through the fan air shutter downstream of the fan inlet, and is discharged outside the aircraft after completing heat exchange.

[0004] The flow demand of the air source system for the cold side of the heat exchanger is different under different flight states of the aircraft. For example, in some working states, the flow demand of the air source system for the cold side of the heat exchanger is zero, at which time the above-mentioned fan air shutter is closed. In this state, the fan inlet becomes a relatively short closed cavity connected to the BIFI on the engine bypass duct. Considering the specific flow field environment of the engine bypass duct, i.e. the general flow velocity is about 0.6 Mach number, as the airflow in the bypass duct flows along the flow direction outside the fan inlet, the closed cavity will produce a huge pressure fluctuation phenomenon. This phenomenon not only produces a large noise, but also brings a huge safety hazard to the aircraft air source system due to vibration, which has a non-negligible impact on the safety and comfort of the aircraft.

[0005] In existing aircraft systems, to avoid the pressure fluctuation problem caused by the above reasons, flow control methods such as increasing the length of the fan inlet, adding guide vanes, or adding bypass branches are usually used to solve the problem.

[0006] However, these solutions often increase the volume of the fan inlet component or significantly reduce the aerodynamic performance of the engine or fan inlet.

[0007] In CN207658077U, CN207740246U and CN107893778A, a fan inlet device with a half-coverage baffle of different structures is added. Such a solution can effectively solve the pressure fluctuation problem, but has a great impact on the flow field of the engine bypass duct, which will significantly increase the fuel consumption of the engine.

[0008] US20100126182A1 and US8024935B2 disclose a technical solution of adding a small blade at the bleed air inlet of a fan inlet device. This solution solves the pressure fluctuation problem by splitting the incoming airflow and forming a wake mixing region downstream of the guide blade. EP0926064B1 also uses a similar approach to solve the pressure fluctuation problem. However, such solutions lead to a significant decrease in the aerodynamic performance of the cold aisle.

[0009] CN110439692A discloses a fan inlet design that includes an airflow branch structure. This design avoids the fan inlet becoming a closed cavity when the valve is closed. However, under normal operating conditions of the aircraft's air supply system, this branch structure significantly reduces the flow rate in the heat exchanger's cold aisle, leading to insufficient heat exchanger capacity and introducing new risks to the aircraft's air supply system. Furthermore, components designed based on this design are difficult to manufacture and install. Summary of the Invention

[0010] This invention addresses the shortcomings of current technical solutions and takes into account the need to minimize the negative impact on the flow field within the engine's outer bypass duct and channel while ensuring the elimination of pressure fluctuations.

[0011] To address this, an aircraft engine fan inlet structure is provided, which is used to introduce airflow from the engine's outer bypass duct into the downstream air supply system.

[0012] in,

[0013] The aircraft engine fan air inlet structure includes:

[0014] The first air intake and the second air intake are disposed on the surface of the rectifier in the outer bypass of the engine.

[0015] The first inlet channel is connected to the first air intake and extends downstream from the first air intake.

[0016] A second inlet channel, which communicates with the second air intake and extends downstream from the second air intake; and

[0017] The main inlet channel is downstream of both the first inlet channel and the second inlet channel and is directly connected to both the first inlet channel and the second inlet channel. The main inlet channel is configured such that the first air intake can be connected to the second air intake via the first inlet channel, the main inlet channel and the second inlet channel in sequence.

[0018] By using two different air inlets and corresponding inlet channels, the airflow entering the main inlet channel when the downstream valve is closed can flow out through the secondary inlet channel. This helps to eliminate pressure fluctuations in the fan intake system and minimizes the impact on the flow field of the bypass duct while ensuring its own efficiency. It is also easy to manufacture, process and install.

[0019] According to a preferred embodiment of the aircraft engine fan inlet structure of the present invention, the first inlet is located upstream of the second inlet in the direction of airflow within the engine bypass duct.

[0020] According to a preferred embodiment of the aircraft engine fan inlet structure of the present invention, the first inlet channel and the second inlet channel are arranged such that, when the downstream of the main inlet channel is unobstructed, the aerodynamic resistance of the airflow flowing downstream from the first inlet channel through the main inlet channel is less than the aerodynamic resistance of the airflow flowing from the first inlet channel through the main inlet channel to the second inlet channel.

[0021] According to a preferred embodiment of the aircraft engine fan inlet structure of the present invention, the first inlet channel and the second inlet channel extend downstream in substantially the same direction relative to the airflow in the engine bypass duct.

[0022] According to a preferred embodiment of the aircraft engine fan air intake structure of the present invention, the first air intake and the second air intake are substantially rectangular inlet openings.

[0023] According to a preferred embodiment of the aircraft engine fan inlet structure of the present invention, the long side of the rectangle is arranged substantially perpendicular to the flow direction of the airflow in the engine's outer bypass duct.

[0024] According to a preferred embodiment of the aircraft engine fan air intake structure of the present invention, the ratio of the area of ​​the first air intake to the area of ​​the second air intake is between 2:1 and 5:1.

[0025] According to a preferred embodiment of the aircraft engine fan inlet structure of the present invention, the flow cross-sectional area of ​​the first inlet channel gradually decreases along the flow direction from the first inlet, and the flow cross-sectional area of ​​the second inlet channel gradually increases along the flow direction from the second inlet.

[0026] According to a preferred embodiment of the aircraft engine fan inlet structure of the present invention, the first inlet channel maintains a flow cross-sectional shape similar to that of the first inlet.

[0027] And / or

[0028] The second inlet channel maintains a flow cross-sectional shape similar to that of the second air inlet.

[0029] Furthermore, the present invention also relates to an aircraft, comprising:

[0030] The aircraft engine fan air inlet structure described above; and

[0031] The downstream air supply system is located downstream of the aircraft engine fan air inlet structure.

[0032] In summary, the technical advantages of the various preferred embodiments of the aircraft engine fan inlet structure according to the present invention are at least as follows:

[0033] 1) Eliminate pressure fluctuations in the fan intake system, minimize the impact on the flow field of the bypass duct while ensuring its own efficiency, and facilitate production, processing and installation.

[0034] 2) As a solution that draws air from one side of the engine's external bypass rectifier, this solution can solve the pressure fluctuation problem when the fan air valve is closed, while ensuring the fan intake section is relatively efficient.

[0035] 3) This scheme does not make geometric changes to the flow path of the engine's outer bypass duct, ensuring that the engine's thrust and the aircraft's fuel efficiency are not affected.

[0036] 4) This solution is relatively simple to process and install, increasing the design redundancy of the aircraft. Attached Figure Description

[0037] This document includes accompanying drawings to provide a further understanding of various embodiments. The drawings are incorporated in and form part of this specification.

[0038] The accompanying drawings illustrate various embodiments described herein and, together with the textual description, serve to explain the principles and operation of the claimed subject matter.

[0039] With reference to the above objectives, the technical features of the present invention are clearly described below, and its advantages will be apparent from the following detailed description with reference to the accompanying drawings, which illustrate preferred embodiments of the invention by way of example, without limiting the scope of the invention.

[0040] In the attached image:

[0041] Figure 1 This is a schematic perspective view of a preferred embodiment of the aircraft engine fan air inlet structure according to the present invention.

[0042] Figure 2 Along the preferred embodiment of the aircraft engine fan air inlet structure according to the present invention Figure 1A schematic top view in a roughly horizontal direction.

[0043] Figure 3 This is a schematic diagram of the internal flow field when the downstream valve is open, according to a preferred embodiment of the aircraft engine fan inlet structure of the present invention.

[0044] Figure 4 This is a schematic diagram of the internal flow field when the downstream valve is closed, according to a preferred embodiment of the aircraft engine fan inlet structure of the present invention.

[0045] List of reference numerals

[0046] 110 First Entrance Passage

[0047] 111 First air intake

[0048] 120 Second Entrance Channel

[0049] 121 Second air intake

[0050] 130 Main Entrance Passage

[0051] Airflow in the outer bypass duct of engine 200

[0052] 300 rectifier

[0053] A. Flow direction Detailed Implementation

[0054] Embodiments of the invention will now be described in detail, examples of which are shown in the accompanying drawings and described below.

[0055] Although the invention will be described in conjunction with exemplary embodiments, it should be understood that this specification is not intended to limit the invention to the embodiments illustrated. Rather, the invention is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of the invention.

[0056] To facilitate explanation and precise definition of the technical solutions of the present invention, the terms "upper," "lower," "inner," and "outer" are used to describe these features with reference to the positions of features in the exemplary embodiments shown in the accompanying drawings.

[0057] Various preferred but non-limiting embodiments of the aircraft engine fan air inlet structure of the present invention will be described in detail below with reference to the accompanying drawings.

[0058] like Figure 1 and Figure 2The diagram illustrates an aircraft engine fan inlet structure according to a preferred embodiment of the present invention. The aircraft engine fan inlet structure is used to introduce airflow 200 from the engine's outer bypass duct into a downstream air supply system. It is conceivable that an aircraft may include this illustrated aircraft engine fan inlet structure and a downstream air supply system located downstream of the aircraft engine fan inlet structure, including but not limited to air supply systems for air conditioning systems, anti-icing systems, etc.

[0059] The air intake structure of the aircraft engine fan includes: a first air intake 111 and a second air intake 121, a first inlet channel 110 and a second inlet channel 120, and a main inlet channel 130.

[0060] The first air intake 111 and the second air intake 121 are disposed on the surface of the rectifier 300 inside the engine bypass duct. It should be noted that the first air intake 111 and the second air intake 121 in this document should be understood as two independent air intakes, such that two separate airflow channels can be formed downstream of the respective air intakes.

[0061] According to the present invention, the arrangement position of the aircraft engine fan air intake structure in the engine bypass, that is, the arrangement position of the rectifier thrust reverser in the engine bypass, can be located at any position on the inner side of the engine circumferential direction, including but not limited to the arrangement position being the 12 o'clock position in the circumferential direction when the aircraft is on the ground, that is, arranged near the top of the engine bypass duct above the engine turbine rotor.

[0062] It should also be noted that during operation, such as Figure 1 The intake structure shown in the diagram actually has bypass mainstream flow on both the near side, close to the paper, and the far side, far from the paper. Although Figure 1 The diagram shows air inlets 111 and 121 facing only the proximal side, but those skilled in the art will understand that, on the one hand, one or more air inlets may additionally or alternatively face the distal side, and on the other hand, in the case where air inlets face only the proximal side, the engine may generally be configured such that the hydrodynamic characteristics of the proximal bypass mainstream are more in line with the downstream bleed air requirements.

[0063] In a preferred embodiment, the first air intake 111 may be located upstream of the second air intake 121 in the flow direction A of the airflow 200 within the engine bypass duct. For example... Figure 1 and Figure 2 As indicated by arrow A in the image, Figure 1 In the middle, the first air intake 111 is located to the right of the second air intake 121. Figure 2 In the middle, the first air intake and its corresponding first inlet channel 110 are located to the left of the second air intake and its corresponding second inlet channel 120.

[0064] In the preferred embodiment, and as Figure 1 As shown, the first air intake 111 and the second air intake 121 are substantially rectangular inlet openings. More preferably, the first air intake 111 and the second air intake can be rectangular openings with one or more chamfered or rounded corners. In a preferred embodiment of such rectangular inlet openings, and more preferably, the long side of the rectangle can be arranged substantially perpendicular to the flow direction A of the airflow 200 within the engine's outer bypass duct, that is, in Figure 1 The arrangement is roughly vertical. It should be noted here that, although... Figure 1 The long side of the rectangle in the figure is roughly a straight line, but those skilled in the art will understand that, depending on the different shapes of the rectifier, the long side of the rectangle may also be a curve.

[0065] In a preferred embodiment, the area of ​​the first air inlet 111 can be larger than the area of ​​the second air inlet 121. Preferably, the ratio of the area of ​​the first air inlet 111 to the area of ​​the second air inlet 121 can be between 2:1 and 5:1, more preferably between 3:1 and 4:1. The specific shape and size of the first air inlet 111 and the second air inlet 121 can be determined by those skilled in the art with reference to the geometric parameters of the bypass duct rectifier and the design parameters of the cold side of the heat exchanger in the air source system, and will not be elaborated further here. Figure 1 As shown, the difference in area can preferably be achieved by a difference in size along the direction of the short side of the rectangle, while keeping the long side of the rectangle in the vertical direction approximately the same length.

[0066] Continue to refer to Figure 1 and Figure 2 The first inlet channel 110 is connected to the first air intake 111 and extends downstream from the first air intake 111. Similarly, the second inlet channel 120 is connected to the second air intake 121 and extends downstream from the second air intake 121.

[0067] According to the present invention, the main inlet channel 130 is directly connected to both the first inlet channel 110 and the second inlet channel 120 downstream. Crucially, the main inlet channel 130 is configured such that the first air intake 111 can sequentially connect to the second air intake 121 via the first inlet channel 110, the main inlet channel 130, and the second inlet channel 120. Preferably, the merging process of the first inlet channel 110 and the second inlet channel 120 can be configured to ensure a smooth transition of the airflow angle and flow path.

[0068] It is conceivable that the main inlet channel 130 has an outlet for the engine fan intake inlet structure of the present invention at its downstream end. Therefore, the engine fan intake inlet structure of the present invention can be understood as a channel section between the inlet and the outlet. Preferably, the length of the first inlet channel 110 and the second inlet channel 120 can account for about 50%-75% of the total length of the channel section of the entire engine fan intake inlet structure, for example, about 55%-70% of the total length.

[0069] The first inlet channel 110 and the second inlet channel 120 are arranged such that when the downstream of the main inlet channel 130 is unobstructed, the aerodynamic resistance of the airflow flowing downstream from the first inlet channel 110 through the main inlet channel 130 is less than the aerodynamic resistance of the airflow flowing from the first inlet channel 110 through the main inlet channel 130 to the second inlet channel 120.

[0070] In a preferred embodiment, the first inlet passage 110 and the second inlet passage 120 extend downstream in substantially the same direction relative to the airflow 200 within the engine bypass duct. More preferably, referring to... Figure 2 The first entrance channel 110 and the second entrance channel 120 extend in a generally parallel direction to each other.

[0071] More preferably, the flow cross-sectional area of ​​the first inlet channel 110 gradually decreases along the flow direction from the first air inlet 111, and the flow cross-sectional area of ​​the second inlet channel 120 gradually increases along the flow direction from the second air inlet 121, so that the airflow velocities inside the junction of the two inlet channels are closer, thereby helping to avoid aerodynamic efficiency loss caused by the mixing of the two airflows at the junction.

[0072] The following is a brief description of the basic operating mode of the engine fan intake structure according to the present invention:

[0073] When the fan air valve of the air supply system opens, both inlets simultaneously draw air from the engine's outer bypass duct to the air supply system, ensuring the normal operation of the air supply system. The internal flow field diagram is shown below. Figure 3 As shown;

[0074] Under certain operating conditions, when the fan air valve is closed, the flow field inside the entire component is as follows: Figure 4 As shown, the airflow enters the cavity through the first inlet channel 110, forming several vortex structures of different scales in the space upstream of the valve, consuming some of the airflow's energy. Finally, the airflow flows out of the cavity through the second inlet channel 120 and returns to the outer bypass duct.

[0075] The preferred embodiments of the present invention have been described in detail above, but it should be understood that, if necessary, aspects of the embodiments can be modified to utilize aspects, features, and concepts from various patents, applications, and publications to provide other embodiments.

[0076] Given the detailed description above, various readily conceivable variations can be made to the embodiments described herein.

[0077] Generally speaking, the terminology used in the claims should not be considered as limited to the specific embodiments disclosed in the specification and claims, but should be understood to include all possible embodiments together with the full scope of equivalents enjoyed by the claims.

Claims

1. An aircraft engine fan inlet structure, said aircraft engine fan inlet structure being used to introduce airflow (200) from the engine's outer bypass duct into a downstream air supply system, in, The aircraft engine fan air inlet structure includes: A first air intake (111) and a second air intake (121) are disposed on the surface of the rectifier (300) in the engine bypass duct, wherein the first air intake (111) is located upstream of the second air intake (121) in the flow direction (A) of the airflow (200) in the engine bypass duct. The first inlet channel (110) is connected to the first air inlet (111) and extends downstream from the first air inlet (111); A second inlet channel (120) is connected to the second air intake (121) and extends downstream from the second air intake (121); and A main inlet channel (130) is located downstream of the first inlet channel (110) and the second inlet channel (120) and is directly connected to both the first inlet channel (110) and the second inlet channel (120). The main inlet channel (130) is configured such that the first air inlet (111) can be connected to the second air inlet (121) in sequence via the first inlet channel (110), the main inlet channel (130) and the second inlet channel (120). The first inlet channel (110) and the second inlet channel (120) are arranged such that when the downstream of the main inlet channel (130) is unobstructed, the aerodynamic resistance of the airflow flowing downstream from the first inlet channel (110) via the main inlet channel (130) is less than the aerodynamic resistance of the airflow flowing downstream from the first inlet channel (110) via the main inlet channel (130) to the second inlet channel (120).

2. The aircraft engine fan air inlet structure according to claim 1, Its features are, The first inlet passage (110) and the second inlet passage (120) extend downstream in substantially the same direction relative to the airflow (200) in the engine bypass duct.

3. The aircraft engine fan air inlet structure according to claim 1, Its features are, The first air intake (111) and the second air intake (121) are substantially rectangular inlet openings.

4. The aircraft engine fan air inlet structure according to claim 3, Its features are, The long side of the rectangle is arranged to be substantially perpendicular to the flow direction (A) of the airflow (200) within the engine's outer bypass duct.

5. The aircraft engine fan air inlet structure according to claim 1, Its features are, The ratio of the area of ​​the first air inlet (111) to the area of ​​the second air inlet (121) is between 2:1 and 5:

1.

6. The aircraft engine fan air inlet structure according to claim 5, Its features are, The flow cross-sectional area of ​​the first inlet channel (110) gradually decreases along the flow direction from the first air inlet (111), and the flow cross-sectional area of ​​the second inlet channel (120) gradually increases along the flow direction from the second air inlet (121).

7. The aircraft engine fan air inlet structure according to claim 6, Its features are, The first inlet channel (110) maintains a similar flow cross-sectional shape to the first air inlet (111). And / or The second inlet channel (120) maintains a similar flow cross-sectional shape to the second air inlet (121).

8. An aircraft comprising: The aircraft engine fan air inlet structure according to any one of claims 1 to 7; as well as The downstream air supply system is located downstream of the aircraft engine fan air inlet structure.

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