CN116537950A - Ventilation cooling air inlet device for turbofan engine core cabin - Google Patents

Abstract

The invention relates to a ventilation cooling air intake device (10) for a turbofan engine core nacelle (5). The ventilation cooling air intake device (10) comprises: a cooling air flow connecting pipe (1); an air intake device housing (2), the air intake device housing (2) having a first end (2 a) communicating with the cooling air flow connection pipe (1), a second end (2 b) opposite to the first end (2 a), and a central axis (X) passing through the first end (2 a) and the second end (2 b); and at least one exhaust grille (3) provided on the air intake device housing (2). The air inlet device housing (2) obtains a maximum cross-sectional area (S) at a first end (2 a) of the housing (2) _max ) While a minimum cross-sectional area (S) is obtained at the second end (2 b) of the housing (2) _min ). The invention utilizes the exhaust grille and the rectifying structure to realize airflow diffusion and direction deflection, relieves the contradiction between improving the air inlet uniformity and reducing the total pressure loss of the current ventilation cooling device, and is beneficial to improving the ventilation cooling efficiency in the core cabin.

Description

Ventilation cooling air inlet device for turbofan engine core cabin

Technical Field

The present invention relates to an improved ventilation cooling air intake, and more particularly to a ventilation cooling air intake for a turbofan engine core nacelle.

Background

During operation of turbofan engines of civil aircraft, their core nacelle is prone to generate a large amount of heat. The ventilation cooling design in the cabin of the core engine is taken as a main measure for cabin internal heat management, and besides ensuring that accessories in the cabin work within a limited temperature, the ventilation cooling design also avoids the accumulation of combustible gas volume and realizes the function of cabin pressure application. On the premise of ensuring temperature control, the weight of the ventilation cooling air inlet device is reduced as much as possible, so that the thrust loss of the engine caused by ventilation air entraining loss is reduced.

As the bypass ratio of new engines continues to increase, the relative cabin volume and the outer bypass pressure ratio gradually decrease, placing more stringent demands on the design of the ventilation cooling intake. However, the two objectives of reducing the total pressure loss and improving the intake uniformity are often difficult to achieve at the same time, limited by the current ventilation cooling intake arrangements of the core cabin of the mainstream civil aircraft.

For example, FIG. 1 is a schematic illustration of a currently commonly used ventilation and cooling air intake 10' for a turbofan engine core nacelle. As shown in fig. 1, the ventilation, cooling and air intake device 10' can be seen to have a generally hollow cylindrical shape overall, with a cross-sectional area taken in each plane perpendicular to its central axis X that is substantially unchanged between the air intake and exhaust ends of the device. Thus, such a ventilation and cooling air intake device 10 'is also referred to in the industry as a "straight-tube air intake device", and has the advantage that the ventilation and cooling air flow in the core nacelle directly flows through the ventilation and cooling air intake device 10' (as indicated by the flow path indicated by the dashed arrow F in fig. 1), the intake air amount is sufficient, the flow velocity in the radial direction in the nacelle is relatively fast, and the cooling effect is relatively remarkable at a local area near the intake port position. However, it has a disadvantage in that the circumferential distribution uniformity of the air flow is poor and the overall cooling effect is not ideal.

Fig. 2 is a schematic illustration of another commonly used ventilation cooling air intake 10 "for a turbofan engine core nacelle. As shown in fig. 2, the ventilation cooling intake device 10 "is modified to a" grill type intake device "by blocking the exhaust end of the straight pipe type intake device 10' and opening a plurality of bar-shaped grilles 3" parallel to each other at the cylinder side wall. In the example shown in fig. 2, the strip-shaped grille 3″ is provided with eight grille elements uniformly along the circumferential direction of the cylinder side wall, each grille element 3″ extending parallel to the central axis X of the ventilation cooling air intake device 10″ and having a length generally set to about half the cylinder length. In this way, the cooling air flow can flow out only from each of the grids 3″ in the circumferential direction (as indicated by the flow path indicated by the broken-line arrow F in fig. 2), and the air flow uniformity is improved to some extent. However, in the ventilation cooling intake device 10", the external flow may directly impinge on the closed exhaust end, which inevitably comes at the cost of total pressure loss, reducing the overall through-flow capacity of the cooling air flow in the core nacelle.

For this reason, numerous designs have emerged in the industry that replace the aforementioned ventilation and cooling air intake devices 10' and 10 ". For example, in chinese patent application CN104943530a entitled "ventilation cooling device for engine core" filed by chinese commercial aeroengine limited on 3 months 27 2014, an adjustable ventilation cooling air intake device is disclosed. The device is installed on the inner wall of the culvert, is provided with three working positions, and can control the air flow entering the core cabin according to the environmental requirement.

In addition, in chinese patent application CN113606045a entitled "a large bypass ratio turbofan engine core cabin ventilation structure and ventilation method thereof" filed by university of aviation aerospace in south kyo at day No. 2021, 7, 15, a core cabin ventilation structure and ventilation method thereof are disclosed. The ventilation method utilizes the stamping air inlet effect to lead the outer culvert air flow into the upstream air inlet circular cavity, and then utilizes the suction effect of the outer culvert air flow to lead the cooling air out through the downstream exhaust grille. However, the above design requires the specialized manufacture of the intake air scoop and its actuation mechanism, and the addition of upstream annular cavities or other cooling devices, including but not limited to actuators driving the scoop, linkages, runners, etc., adjustment assemblies capable of adjusting the amount of airflow entering the core nacelle via the intake, annular cavity structures to improve airflow distribution, and downstream suction and exhaust grille structures, etc. However, the manufacturing costs of these components are significantly higher than for the ventilation cooling intake 10', 10″ and there is a risk of interference of the added structure with the cabin accessories.

For this reason, it is required to design a low-cost ventilation and cooling intake device for a turbofan engine core nacelle, which can achieve both of the purposes of reducing the total pressure loss and improving the intake uniformity.

Disclosure of Invention

The invention aims to provide a ventilation cooling air inlet device which improves the ventilation heat exchange efficiency in a turbofan engine core cabin at lower cost.

According to a first aspect the present invention relates to a ventilation and cooling air intake device for a turbofan engine core nacelle, comprising:

a cooling air flow duct for allowing air flow into the core nacelle;

an air intake housing having a first or air intake end in communication with the cooling air flow receiving duct, a second or opposite end opposite the first end, and a central axis passing through the first and second ends; and

at least one exhaust grille arranged on the air inlet device shell,

wherein the cross-sectional area of the air intake housing taken in respective planes perpendicular to the central axis obtains a maximum cross-sectional area at a first end of the housing and a minimum cross-sectional area at a second end of the housing.

Compared with the straight pipe type air inlet device in the prior art, the inverted cone type air inlet device ensures that cooling air entering the sudden expansion flow passage can be directly sprayed out along the inclined lower direction by the grid under the drive of internal high pressure. This improves the uniformity of the air flow distribution within the core nacelle to a large extent while achieving a larger range of convective heat transfer area centered on the ventilation cooled intake.

Compared with a grid type air inlet device in the prior art, the reverse cone type air inlet device disclosed by the invention has the advantages that the sudden expansion shape is utilized to lead the cross section area of the air flow channel to be amplified in a step-type manner, so that the cooling air is pressurized, the impact effect on the bottom surface of the air inlet device is weakened, meanwhile, a backflow area or even a vortex structure is formed at the upper part of the conical surface structure of the reverse cone, the anti-interference capability of air flow is improved, and the sensitivity of ventilation efficiency to total external pressure is reduced.

In the preferred embodiment of the present application, the "reverse taper air intake" is typically a cone, but may also be a pyramid or other taper. In the case where the "inverted cone air intake device" has a pyramid shape, the exhaust grill may be formed on at least one of the facets of the pyramid.

Preferably, the air intake housing is formed of a cross-sectional abrupt expansion section and a cross-sectional tapered section, the cross-sectional area of the cross-sectional abrupt expansion section having a discontinuous rate of change in area along the path at or near the first end, the cross-sectional area of the cross-sectional tapered section monotonically decreasing in a direction from the first end to the second end.

More preferably, the cross-sectional area of the cross-sectional flared section is a maximum cross-sectional area, and the cross-sectional area of the cross-sectional tapered section tapers from the maximum cross-sectional area to a minimum cross-sectional area at a constant or varying rate.

In a preferred embodiment, the cross-sectional abrupt expansion may be formed at the first end as a cone top surface substantially perpendicular to the central axis. In yet another preferred embodiment, the cross-sectional tapered section may form a hemispherical bottom surface at the second end that is concave toward the first end.

Preferably, the radius of the sphere of the hemispherical bottom surface may be greater than the radius corresponding to the smallest cross-sectional area, and the surface area of the hemispherical bottom surface may be less than half the surface area of the corresponding equal radius complete sphere.

In the preferred embodiment, the hemispherical bottom surface is arranged to enable the reflection direction of the impact air flow to deviate along the radial direction of the bottom surface, and the impact air flow can directly escape through the grille under ideal conditions, so that the cooling air flow is prevented from impacting the wall surface of the air inlet structure for multiple times, and the total pressure loss is reduced.

As for the exhaust grill, a plurality of exhaust grilles may be formed on the air intake device housing, and the exhaust grilles are uniformly distributed on the air intake device housing around the central axis.

Preferably, ten exhaust grilles may be formed in total on the air intake device housing, and formed only on the cross-sectional constricted section of the air intake device housing.

More preferably, the length of the exhaust grill may be more than three-quarters of the total length of the air intake device housing along its central axis.

According to a second aspect of the invention, a turbofan engine core nacelle is provided with at least one ventilation and cooling air intake device according to the first aspect of the invention upstream of the intake of the core nacelle,

the cooling air flow enters the air inlet device shell through the cooling air flow guide pipe, is diffused through the cross section sudden expansion section and deflected through the cross section gradually-reduced section, is scattered into the turbofan engine core cabin through the exhaust grille, and is finally discharged out of the turbofan engine core cabin from a downstream outlet positioned at the downstream of the turbofan engine core cabin.

Preferably, the cooling air flow ducts may be affixed to the core cabin wall face.

According to a third aspect the invention relates to an aircraft equipped with a turbofan engine core nacelle according to the second aspect of the invention.

The ventilation cooling air intake device for a turbofan engine core nacelle according to the invention can obtain the following advantages:

(i) The abrupt expansion shape of the housing of the air inlet device causes the cross-sectional area of the air flow passage to be amplified in a stepwise manner, so that a backflow area and even a vortex structure are formed at the upper part of the conical surface structure of the reverse cone. On one hand, the backflow mode greatly weakens the impact action of the hemispherical bottom surface along the way diffusion, on the other hand, the stability of cooling air flow is increased, and the sensitivity of ventilation efficiency to total external pressure is reduced.

(ii) The hemispherical bottom surface at the second end of the cross-section tapered section deflects the direction of reflection of the impinging air stream radially along the bottom surface, and in an ideal situation, the impinging air stream can directly escape the housing through the grille, thereby inhibiting the cooling air stream from striking the wall surface of the air inlet for multiple times, reducing the total pressure loss, and ensuring that the cooling air stream still maintains a higher flow rate.

(iii) After the cooling gas introduced from the external culvert enters the sudden expansion flow channel, the cooling gas is driven by the internal high pressure and is radially sprayed out along the inclined lower part through the grille. This not only improves the uniformity of the air flow distribution within the core nacelle, but also achieves a larger range of convective heat transfer areas centered on the ventilation cooled intake.

Drawings

In order to further illustrate the technical effects of the ventilation cooling air intake device for turbofan engine core nacelle according to the invention, the invention will be described in detail below with reference to the accompanying drawings and detailed description, wherein:

fig. 1 schematically illustrates a prior art ventilation cooling air intake device for a turbofan engine core nacelle, wherein the dashed arrow F shows the flow path of the air flow in the device;

fig. 2 schematically illustrates another prior art ventilation cooling intake arrangement for a turbofan engine core nacelle, wherein the dashed arrow F shows the flow path of the air flow in the arrangement;

FIG. 3 is a perspective view of a ventilation cooling air intake for a turbofan engine core nacelle according to the invention;

FIG. 4 is a schematic view of the ventilation cooling air intake device of FIG. 3 taken along a central axis;

FIG. 5 is a front view of the ventilation cooling air intake shown in FIG. 3, taken along a central axis and in cross section;

FIG. 6 is a top view of the ventilation cooling air intake shown in FIG. 3;

FIG. 7 is a bottom view of the ventilation, cooling and air intake device shown in FIG. 3;

FIG. 8 is the same schematic view as FIG. 5, wherein the dashed arrow F shows the flow path of the air flow in the device;

FIG. 9 is a simplified nacelle schematic diagram of the ventilation cooling air intake shown in FIG. 3 after installation in a turbofan engine core nacelle, wherein dashed arrow F illustrates the flow path of air flow through the core nacelle; and

fig. 10 shows simulation results of three intake types of straight pipe type, grid type and reverse cone type.

Reference numerals

1. Cooling air flow connecting tube

2. Air inlet device shell

2-I cross-section abrupt expansion segment

2-II cross-section tapered section

2a first or inlet end

2b second or opposite end

3. 3' exhaust grille

4. Hemispherical bottom surface

5. Turbofan engine core nacelle

6. Wall surface of core machine

7. Downstream outlet

10. 10', 10' ventilation cooling air intake device

X central axis

S cross-sectional area

S _max Maximum cross-sectional area

S _min Minimum cross-sectional area

F flow path

Detailed Description

The configuration of the ventilation cooling air intake device for a turbofan engine core nacelle, the cooling process and the effects thereof according to the invention are described below with reference to the accompanying drawings.

It should be understood that the several embodiments described in this specification are intended to cover only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art without making any inventive effort, based on the embodiments described in the specification should be considered as falling within the scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description presented herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprising" and "having" and any variations thereof in the present specification and claims and in the foregoing description of the drawings are intended to cover non-exclusive inclusions. As used in the specification of the present application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It is to be understood that, based on the same orientation, in the present specification, the terms "length", "top", "bottom", "front", "rear", "upstream", downstream ", etc. refer to a position or orientation relationship based on that shown in the drawings. This is merely to facilitate describing the invention and to simplify the description and does not indicate or imply that the device or element in question must have a particular position or orientation, be constructed and operate in a particular position or orientation, and therefore should not be construed as limiting the invention.

Fig. 3 is a perspective view of the ventilation cooling air intake device 10 for a turbofan engine core nacelle according to the present invention, and fig. 4 is a sectional view of the ventilation cooling air intake device 10 shown in fig. 3.

As shown in fig. 3, the ventilation cooling air intake device 10 for a turbofan engine core nacelle according to the present invention includes: a cooling air flow connection duct 1 for allowing an air flow into the core nacelle; an air intake device housing 2, the air intake device housing 2 having a first or air intake end 2a in communication with the cooling air flow receiving duct 1, a second or opposite end 2b opposite the air intake end 2a, and a central axis X passing through the air intake end 2a and the opposite end 2 b; and a plurality of exhaust grilles 3 opened on the air intake device housing 2.

As shown in fig. 4, the cooling air flow connection pipe 1 is constituted by a sleeve or the like of a substantially cylindrical shape, and is fixedly attached to the core cabin wall surface of the core cabin by a connecting means such as riveting, welding, adhesive, or the like. The cooling air flow connection duct 1 has opposite ends, one of which communicates with a source of air (not shown) supplying air to the core nacelle and the other of which communicates with the air intake housing 2 to allow air flow into the air intake housing 2 and subsequently into the core nacelle.

In an alternative embodiment, the cooling air flow connection pipe 1 may also be formed by other shaped pipe elements, such as square pipes, which modifications will readily occur to those skilled in the art and thus shall fall within the scope of the invention.

Fig. 5 to 7 are front, top and bottom views, respectively, of the ventilation cooling air intake device 10 of fig. 3, and fig. 8 shows the flow path F of the air flow in the device.

It can be seen that the central axis X of the air intake housing 2 and the flow path F of the air flow just entering the air intake housing 2 are parallel to each other and pass through the air intake end 2a and the opposite end 2b of the air intake housing 2. For example, in the case where the cooling air flow guide pipe 1 is located directly above the air intake device housing 2, the center axis X extends in the vertical direction, as shown in fig. 3.

Two points where the central axis X passes through the air inlet end 2a and the opposite end 2b of the air inlet device housing 2 are defined as centers of the air inlet end 2a and the opposite end 2b, respectively, wherein the air inlet end 2a of the air inlet device housing 2 communicates with one of the ends of the cooling air flow guiding tube 1, and the opposite end 2b of the air inlet device housing 2 is closed and recessed toward the air inlet end 2a to form a hemispherical bottom surface 4, which can be clearly seen in fig. 4.

As shown in fig. 5, innumerable cross sections perpendicular to the central axis X of the air intake housing 2 can be obtained along the central axis X, and the area S of these cross sections varies accordingly based on the shape change of the air intake housing 2. In the present application, the air intake device housing 2 is designed to have the following shape, namely: the cross-sectional area S of the housing taken in respective planes perpendicular to the central axis X obtains a maximum cross-sectional area S at the air intake end 2a of the housing _max While a minimum cross-sectional area S is obtained at the opposite end 2b of the housing _min 。

Taking the air intake housing 2 shown in fig. 5 as an example, the air intake housing 2 is shown having a substantially reverse taper shape. In this case, the cross-sectional area of the intake device housing 2 perpendicular to the central axis X at the intake end 2a is the maximum value S _max While the cross-sectional area of the intake device housing 2 perpendicular to the central axis X at the opposite end 2b is a minimum value S _min . The section of the intake housing 2 at the intake end 2a is defined as a cross-sectional sudden expansion section 2-I of the intake housing 2, while the other sections of the intake housing 2 are defined as cross-sectional gradual expansion sections 2-II. That is, the intake housing 2 is constituted by a cross-sectional sudden expansion section 2-I and a cross-sectional tapered section 2-II.

By "cross-sectional abrupt expansion" is meant that the cross-sectional area S of the cross-sectional abrupt expansion 2-I is enlarged at the air inlet end 2a along Cheng Jieyue, with a discontinuous rate of area change. In other words, the cross-sectional area S of the cross-sectional abrupt expansion section 2-I suddenly reaches the maximum cross-sectional area S at the air intake end 2a _max And is formed as a cone top surface substantially perpendicular to the central axis X.

By "cross-sectional tapered section" is meant that the cross-sectional area S of the cross-sectional tapered section 2-II decreases monotonically in the direction from the inlet end 2a to the opposite end 2b. In other words, the cross-sectional area S of the cross-sectional tapered section 2-II is from the maximum cross-sectional area S _max Is tapered to a minimum cross-sectional area S at a constant or varying rate _min . Under the condition of constant ratio, the cross section tapered section 2-II is a tapered conical surface; however, in case of a change in the ratio, the cross-sectional tapering section 2-II may have various forms, such as forming a transition step between two tapering surfaces, etc. Such modifications should be readily apparent to those of ordinary skill in the art and, therefore, are intended to fall within the scope of the invention.

Thus, the abrupt expansion shape causes the cross-sectional area of the gas flow passage to be stepwise enlarged, so that a backflow region and even a vortex structure are formed at the upper portion of the conical surface structure of the reverse cone. On one hand, the backflow mode greatly weakens the impact effect on the bottom surface of the air inlet device along the way diffusion, on the other hand, the cooling capacity is increased to increase the anti-interference capacity of the air flow, and the sensitivity of the ventilation efficiency to the total external pressure is reduced.

As previously described, the hemispherical bottom surface 4 of the air intake device housing 2 formed at the opposite end 2b is a preferred embodiment. The hemispherical bottom surface 4 is shaped to cause the reflection direction of the impinging air flow to deviate along the radial direction of the bottom surface (see the dashed arrow F in fig. 8), and in an ideal case, the impinging air flow can directly escape from the air inlet device housing 2, so that the cooling air flow is prevented from impacting the wall surface of the air inlet structure for a plurality of times, the total pressure loss is reduced, and the cooling air flow still maintains a high flow rate.

It will be understood by those of ordinary skill in the art that a "hemispherical bottom surface" also encompasses a sphere that is less than a hemisphere. Thus, the radius of the sphere of the hemispherical bottom surface may be greater than the minimum cross-sectional area S _min Corresponding radius. That is, the surface area of the hemispherical bottom surface may be less than half the spherical volume of a corresponding full sphere of equal radius.

In the preferred embodiment, the hemispherical bottom surface 4 can promote the reflection direction of the impact air flow to deviate along the radial direction of the bottom surface, and the impact air flow can directly escape through the grille under ideal conditions, thereby inhibiting the cooling air flow from impacting the wall surface of the air inlet structure for multiple times and reducing the total pressure loss.

Fig. 6 and 7 clearly show that a plurality of exhaust grilles 3 are formed on the air intake device housing 2. These exhaust grilles 3 are uniformly distributed on the air intake device housing 2 around the central axis X of the air intake device housing 2. In the example shown in fig. 6 and 7, ten exhaust gratings 3 are formed in total on the intake device housing 2, and these exhaust gratings 3 are formed only on the cross-sectional tapered sections 2-II of the intake device housing 2.

As can be seen from fig. 7, the length of the exhaust grill 3 distributed in the cross-sectional constricted section 2-II exceeds more than three fourths of the total length of the cross-sectional constricted section 2-II along its central axis X, and may even reach 80% or more. In this way, after the cooling gas introduced from the external conduit enters the sudden expansion flow path, the cooling gas is driven by the internal high pressure and is radially ejected obliquely downward through the exhaust grill 3. This not only improves the uniformity of the air flow distribution within the core nacelle to a great extent, but also ensures a large range of convective heat transfer area centered on the air intake.

Various changes and modifications in the number, size, distribution, etc. of the exhaust grill 3 may be made by those skilled in the art, and such modifications should be readily apparent to those skilled in the art, and thus should fall within the scope of the present invention.

In order to verify the feasibility of the air intake device according to the invention, the inventors have also performed hydrodynamic simulation analyses on different types of air intake devices. Referring to fig. 10, simulation results for three intake types, straight tube, grid, and inverted cone, are listed.

The second column of the table in fig. 10 shows the total pressure cloud and streamline distribution of the cooling gas with the same initial condition after passing through the air inlet devices of the three air inlet types, wherein the fan-shaped area is a partial area on the axial section of the core cabin, and the upper and lower boundaries of the sector respectively represent a part of the outer wall surface and the inner wall surface of the core cabin. According to the analysis structure shown in the third column of the table, the back taper type air inlet device reduces the total pressure loss from 10.37% to 5.33% of the grid type air inlet device, and although the relief of the total pressure loss by the straight pipe type air inlet device is not better, the space occupation ratio of the ineffective heat exchange area (namely, the area with the average flow velocity less than 5% of the inlet speed) is reduced, the numerical value is improved by 35% compared with that of the straight pipe type air inlet device, and the uniformity of gas distribution in the engine room is greatly improved.

Turning to fig. 8, there is shown a ventilation cooling air intake 10 installed in a turbofan engine core nacelle 5. The ventilation cooling air intake devices 10 arranged in pairs upstream of the intake air of the turbofan engine core nacelle 5 can be seen, of course, a plurality of pairs or a plurality of ventilation cooling air intake devices 10 may be installed as appropriate.

It can be seen that the upstream end of the cooling air flow connection pipe 1 of the air intake device housing 2 is fixedly connected with the wall surface 6 of the core cabin, and the cooling air flow from the external culvert firstly enters the air intake device housing 2 through the cooling air flow connection pipe 1 for rectification, and then is scattered and discharged to the surrounding space through the exhaust grille 3.

The cooling gas is driven by the upstream-downstream pressure difference inside the turbofan engine core nacelle 5, flows downstream along the flow path F indicated by the dashed arrow in fig. 9, and exchanges heat with the accessories and walls inside the core nacelle 5 sufficiently. The warmed cooling gas is finally discharged from the downstream outlet 7, completing the ventilation cooling process.

In the ventilation and heat exchange mechanism, the upstream and downstream pressure difference inside the turbofan engine core nacelle 5 determines the overall ventilation capacity, and the upstream gas uniformity is the key of the overall gas flow distribution of the nacelle section. The conical surface structure reduces incoming flow loss through sudden expansion pressurization and deflection airflow steering, and the circumferentially distributed grids enable gas to be timely diffused and distributed to the upstream area of the core cabin, so that the gas circulation stability and incoming flow space uniformity are guaranteed, and efficient ventilation and heat exchange in the core cabin are facilitated.

While the structure and principles of operation of the ventilation and cooling air intake apparatus for a turbofan engine core nacelle according to the invention have been described above in connection with the preferred embodiments and the accompanying drawings, it will be appreciated by those of ordinary skill in the art that the foregoing examples are intended to be illustrative only and are not to be construed as limiting the invention. Therefore, the present invention can be modified and changed within the spirit of the claims, and all such modifications and changes fall within the scope of the claims of the present invention.

Claims (11)

1. A ventilation cooling air intake (10) for a turbofan engine core nacelle (5), comprising:

a cooling air flow connection duct (1) allowing an air flow to enter the turbofan engine core nacelle (5);

an air intake device housing (2), the air intake device housing (2) having a first end (2 a) in communication with the cooling air flow connection duct (1), a second end (2 b) opposite the first end (2 a), and a central axis (X) passing through the first end (2 a) and the second end (2 b); and

at least one exhaust grille (3) arranged on the air inlet device shell (2),

characterized in that the cross-sectional area (S) of the air inlet device housing (2) taken in respective planes perpendicular to the central axis (X) obtains a maximum cross-sectional area (S) at the first end (2 a) of the housing (2) _max ) While a minimum cross-sectional area (S) is obtained at the second end (2 b) of the housing (2) _min )。

2. The ventilation cooling air intake (10) of claim 1, wherein the air intake housing (2) is comprised of a cross-sectional sudden expansion section (2-I) and a cross-sectional tapered section (2-II), the cross-sectional area of the cross-sectional sudden expansion section (2-I) having a discontinuous rate of change of area along the path at the first end (2 a), the cross-sectional area of the cross-sectional tapered section (2-II) monotonically decreasing in a direction from the first end (2 a) to the second end (2 b).

3. A ventilation cooling air intake (10) according to claim 2, wherein the cross-sectional area (S) of the cross-sectional sudden expansion section (2-I) is the largest cross-sectional area (S) _max ) The cross-sectional area (S) of the cross-sectional tapered section (2-II) is from the maximum cross-sectional area (S) _max ) Is tapered to a minimum cross-sectional area at a constant or varying rate (S _min )。

4. The ventilation cooling air intake device (10) according to claim 2, characterized in that the cross-sectional flared section (2-I) is formed at the first end (2 a) as a cone top surface substantially perpendicular to the central axis (X) and/or the cross-sectional tapered section (2-II) is formed at the second end (2 b) as a hemispherical bottom surface (4) recessed towards the first end (2 a).

5. A ventilation cooling air intake (10) according to claim 4, wherein the hemispherical bottom surface (4) has a sphere radius greater than the minimum cross-sectional area (S _min ) The surface area of the hemispherical bottom surface (4) is smaller than half of the surface area of the corresponding equal-radius complete sphere.

6. A ventilation and cooling air intake device (10) according to claim 2, characterized in that the air intake device housing (2) is formed with a plurality of the exhaust grille (3), the exhaust grille (3) being evenly distributed over the air intake device housing (2) around the central axis (X).

7. The ventilation and cooling air intake device (10) according to claim 6, characterized in that ten exhaust grilles (3) are formed in total on the air intake device (2) and are formed only on the cross-sectional tapered section (2-II) of the air intake device (2).

8. The ventilation cooling air intake (10) of claim 6, characterized in that the length of the exhaust grill (3) is more than three-quarters of the total length of the air intake housing (2) along its central axis (X).

9. A turbofan engine core nacelle (5) with at least one ventilation cooling air intake device (10) according to any of claims 1 to 8 arranged circumferentially upstream of the intake of the turbofan engine core nacelle (5),

the cooling airflow enters the air inlet device shell (2) through the cooling airflow guide pipe (1), is diffused through the cross section sudden expansion section (2-I) and deflected through the cross section gradual expansion section (2-II) in sequence, is scattered into the turbofan engine core cabin (5) through the exhaust grid (3), and is finally discharged out of the turbofan engine core cabin (5) from a downstream outlet (7) positioned at the downstream of the turbofan engine core cabin (5).

10. Turbofan engine core nacelle (5) according to claim 9, wherein the cooling air flow connection pipe (1) is fixedly connected to the core nacelle wall (6).

11. Aircraft equipped with a turbofan engine core nacelle (5) according to claim 9.