Lip structure of air inlet channel and turbine propeller engine

Abstract

The invention relates to a lip structure of an air inlet channel, which comprises a lip main body, the lip main body is a hyperelliptical annular component, the lip main body comprises a first side wall and a second side wall, the first side wall and the second side wall are arranged side by side and bent towards the same side, the first side wall and the second side wall are symmetrical about the center line L0 of the section of the lip, and the central line L0 of the section of the lip is a curve with a partial hyperelliptical shape. The shape of the lip is controlled by using the section center line of the partially hyper-elliptical lip, so that the whole lip is hyper-elliptical, the hyper-elliptical design parameters are few, a complicated curve can be designed through the few design parameters, the hyper-elliptical curvature change is continuous, and the sudden change of the curvature is avoided; the first section curve and the second section curve of the lip are also hyperelliptic curves, so that vortex is prevented from being generated on the surface of the inner side wall of the lip when airflow enters the lip, and meanwhile, the influence of the vortex on an airflow field on the surface of the inner side wall can be reduced.

Description

Technical Field

[0001] This application relates to the technical field of the lip of an air intake, and more particularly to a lip structure of an air intake and a turboprop engine. Background Art

[0002] The lip is an important component of the intake part of a propeller engine, and its shape and design have an important impact on the performance of the engine.

[0003] When an aircraft is in flight, it has many states, including high angle of attack and large sideslip. Among them, the high angle of attack means that when the angle of attack of the aircraft exceeds a certain value, the lift coefficient of the aircraft begins to decrease, and at the same time, the drag coefficient increases sharply. In the high angle of attack flight state, the aircraft obtains better low-speed maneuverability and better handling stability. Most importantly, the high angle of attack flight ensures the nose pointing of the aircraft, making it easier for the aircraft to lock and unlock; Large sideslip refers to the flight state when the included angle between the flight speed vector of the aircraft and its longitudinal symmetry plane is relatively large. Among them, the sideslip angle is the included angle between the flight speed vector of the aircraft and its longitudinal symmetry plane. If the speed vector is on the right side of the symmetry plane, the corresponding sideslip angle is positive, and vice versa. Most existing lips are circular or elliptical lips, which will cause the lip to be greatly affected by high angle of attack or large sideslip. When in high angle of attack or large sideslip, the airflow separation occurs at the lip part, generating eddy currents. To meet the flight state of the aircraft in high angle of attack or large sideslip, it is necessary to expand the engine operating envelope, so a special design of the lip cross-section shape is required. The existing scheme of using a circular design for the lip involves many parameters and is relatively complex in design. At the same time, when facing the flight state of high angle of attack or large sideslip, eddy currents are easily generated. Summary of the Invention

[0004] This application provides a lip structure of an air intake and a turboprop engine, which can solve the problems that the existing circular or elliptical lips are complex in design and prone to generating eddy currents when facing the flight state of high angle of attack or large sideslip, affecting the air intake flow field.

[0005] The technical solution of this application is as follows: A lip structure of an air intake includes a lip main body, the lip main body is a super-elliptical annular member, the lip main body includes a first side wall and a second side wall, the first side wall and the second side wall are arranged side by side and bend to the same side, the first side wall and the second side wall are symmetric about the lip cross-section center line L0, the lip cross-section center line L0 is a curve with a partial super-elliptical shape, the cross-sections of the first side wall and the second side wall are both arc-shaped surfaces with a partial super-elliptical shape, and the cross-section width of the first side wall and the second side wall gradually increases along the air intake direction; Define the shape curve of the outer circle of the lip body as the outer contour curve L1, and the outer contour curve L1 satisfies the formula: where a1 is the major axis length of the outer contour curve L1 in the curved part, b1 is the minor axis length of the outer contour curve L1 in the curved part, m1 is the x-term exponent of the outer contour curve L1, and n1 is the y-term exponent of the outer contour curve L1; Define the shape curve of the inner circle of the lip body as the inner contour curve L2, and the inner contour curve L2 satisfies the formula: a2 is the major axis length of the outer contour curve L2 in the curved part, b2 is the minor axis length of the outer contour curve L2 in the curved part, m2 is the x-term exponent of the outer contour curve L2, and n2 is the y-term exponent of the outer contour curve L2.

[0006] By adopting the above scheme, the shape of the lip is controlled by using the center line of the lip cross-section with a partial super-elliptical shape, making the whole lip a super-ellipse. The super-ellipse has fewer design parameters, and a more complex curve can be designed with fewer design parameters. Moreover, the curvature change of the super-ellipse is continuous without sudden curvature changes. In addition, the cross-sections of the first side wall and the second side wall of the lip body are also arc surfaces with a super-elliptical shape, thereby avoiding the generation of eddy currents on the inner side wall surface when the air flow enters the lip, and at the same time being able to reduce the influence of the swirling flow on the air flow field on the inner side wall surface.

[0007] In one embodiment of the present application, the lip body further includes two connecting parts, and the two connecting parts are respectively assembled at both ends of the first side wall and the second side wall and enclose to form the lip body. The two connecting parts are continuous with the surface curvatures of the first side wall and the second side wall.

[0008] By adopting the above scheme, by using the connecting parts connected to the two side walls, the connecting parts can be matched with the intake duct of the engine, making the curvature of the whole lip body more continuous and reducing the influence of air resistance on the lip body.

[0009] In one embodiment of the present application, the first side wall includes a first side wall inner surface and a first side wall outer surface. The first side wall inner surface and the first side wall outer surface enclose to form the first side wall. One side of the first side wall inner surface and the first side wall outer surface approaches each other and is connected to form a connecting contour curve segment L31 with a partial super-elliptical shape; The second side wall includes an inner surface of the second side wall and an outer surface of the second side wall. The inner surface of the second side wall and the outer surface of the second side wall enclose to form the second side wall. The inner surface of the first side wall and one side of the outer surface of the second side wall are close to each other and are connected to form a connecting contour curve segment L32 with a partial super-elliptical shape. The two ends of the connecting contour curve segment L31 and the connecting contour curve segment L32 are connected end to end to form an annular connecting contour curve L3. The connecting contour curve L3 satisfies the formula: a3 is the major axis length of the outer contour curve L3 in the curve part, b3 is the minor axis length of the outer contour curve L3 in the curve part, m3 is the x-term exponent of the outer contour curve L3, and n3 is the y-term exponent of the outer contour curve L3; The projections of the inner surface of the first side wall and the inner surface of the second side wall on the vertical plane are connected to form an inner contour curve L2 with a super-elliptical shape. The ratio C1 of the area of the super-ellipse where the connecting contour curve L3 is located to the area of the super-ellipse where the inner contour curve L2 is located satisfies: 1.1 ≤ C1 ≤ 1.5.

[0010] By adopting the above scheme, by designing three outer contour curves L1, inner contour curve L2 and connecting contour curve L3 that are all super-elliptical curves, when designing the structural shape of the entire lip, due to the fewer parameters of the super-elliptical design, the design is more convenient, the curvature does not change suddenly, and the aerodynamic layout is more reasonable. By setting the ratio of C1, the contraction ratio between the inner surface of the lip body and the intake duct is regulated, thereby optimizing the flow field structure and aerodynamic performance of the intake duct.

[0011] In one embodiment of the present application, the projections of the outer surface of the first side wall and the outer surface of the second side wall on the vertical plane are connected to form an outer contour curve L1 with a super-elliptical shape. The ratio C2 of the area of the super-ellipse where the connecting contour curve L3 is located to the area of the super-ellipse where the outer contour curve L1 is located satisfies: 1.1 ≤ C2 ≤ 15.

[0012] By adopting the above scheme, by setting the ratio of C2 and cooperating with the ratio of C1, the contraction ratio between the inner and outer surfaces of the lip body and the intake duct is regulated, thereby further optimizing the flow field structure and aerodynamic performance of the intake duct.

[0013] In one embodiment of the present application, the cross-sections of the inner surface of the first side wall, the outer surface of the first side wall, the inner surface of the second side wall and the outer surface of the second side wall are all arc segments with a partial super-elliptical shape. The super-elliptical shapes of the cross-sections of the outer surface of the first side wall and the outer surface of the second side wall are the same, and the super-elliptical shapes of the cross-sections of the inner surface of the first side wall, the inner surface of the second side wall and the outer surface of the first side wall are different from each other.

[0014] By adopting the above technical solution, through setting, the cross-sections of the inner surface of the first side wall, the outer surface of the first side wall, the inner surface of the second side wall, and the outer surface of the second side wall are all arc segments with a partially super-elliptical shape, so that when the lip body is in a flight state of large angle of attack or large sideslip of the aircraft, the influence on the airflow on the more continuously curved inner surfaces of the first side wall and the second side wall is reduced, and no eddy current will be generated. In addition, due to the influence of the rotation of the propeller on the flow field behind the propeller, the swirling flow generated by the rotation of the fluid in the flow field, the more continuously curved super-elliptical inner surfaces of the first side wall and the second side wall can effectively reduce the influence of the swirling flow on the airflow.

[0015] In one embodiment of the present application, the lip structure of the air inlet further includes an annular sealing plate that fits the shape of the lip body. The lip body is an annular member with a hollow interior. One side of the lip body is provided with an opening. The annular sealing plate is hermetically assembled at the opening of the lip body. The interior of the lip body is filled with a heating liquid, and a heating component that can extend into the interior of the lip body is provided on the annular sealing plate.

[0016] By adopting the above technical solution, when it is necessary to deal with the icing on the surface of the lip of the engine, by using the heating component to heat the heating liquid, since the heating liquid is filled in the lip structure with a hollow interior, the inner surface of the lip structure is heated more evenly, preventing the phenomenon of icing on the lip surface.

[0017] In one embodiment of the present application, the heating component includes a heating rod. One end of the heating rod is assembled on the annular sealing plate, and the other end extends into the interior of the lip body. A cavity extending along the length direction of the heating rod is provided inside the heating rod, and an electric heating wire is provided inside the cavity.

[0018] By adopting the above technical solution, by energizing the electric heating wire inside, the heating rod generates heat, and the heat can be radiated into the heating liquid, so as to quickly raise the temperature of the heating liquid inside the lip body to avoid icing on the lip surface. In one embodiment of the present application, the heating liquid is water or glycerol.

[0019] By adopting the above solution, while heating the heating liquid, using water or glycerol with a relatively high coefficient of thermal expansion as the heating liquid, when heated, the heating liquid expands inside the lip body, thereby generating a certain pressure on the inner wall surface of the lip body, so that when the lip body is flying, the pressure of the internal heating liquid can balance a part of the pressure generated by the external airflow on the outer surface of the lip body, avoiding deformation of the lip due to the influence of the airflow pressure, thereby affecting the aerodynamic effect of the device.

[0020] In one embodiment of the present application, the lip structure of the air inlet further includes a support member, the support member includes at least two support sheets, at least two of the support sheets are coaxially sleeved on the heating rod and are spaced along the length direction of the heating rod, and the support sheet is connected and abutted against the inner wall of the lip body.

[0021] By adopting the above solution, support sheets are arranged on the heating rod, and the support sheets are used to support each point inside the hollow lip body, so that on the premise of reducing the material used for the lip body, the structural strength of the lip body can be further improved.

[0022] The present invention relates to a turboprop engine, and its technical solution is as follows: a turboprop engine includes a lip structure of an air inlet.

[0023] In one embodiment of the present application, In summary, the present application includes at least one of the following beneficial technical effects: 1. By adopting the first side wall and the second side wall with a partially super-elliptical shape, the inner and outer surfaces of the first side wall and the second side wall of the lip body are both curved surfaces with more continuous curvature. Then, according to the different influences of the airflow at the location on the flow field, the inner and outer surfaces of the first side wall and the second side wall are set as super-elliptical curves with different characteristics, so that the situation of airflow generating vortices can be effectively reduced, and the influence of the swirl generated when the propeller rotates on the airflow entering the lip can also be effectively reduced, and the influence of the airflow on the outer surface of the lip on the flow field of the air inlet can be improved.

[0024] 2. By adopting a lip body that is a super-elliptical member, when designing the lip body, the characteristics of fewer design parameters of the super-ellipse can be utilized, reducing the complexity of the design scheme and improving the convenience during design.

[0025] 3. By limiting the area ratio of the connecting contour curve L3 to the inner contour curve L2 in the vertical plane, and the area ratio of the outer contour curve L1 to the connecting contour curve L3 in the vertical plane, the contraction ratio of the lip can be quantified to a certain extent, making it more convenient to improve the aerodynamic performance of the intake when designing the lip according to the air inlet.

[0026] 4. By setting the lip body to be hollow and arranging a heating liquid with a relatively high coefficient of thermal expansion in the hollow lip body, by heating the heating liquid to raise the temperature, the lip body can avoid icing due to the low surface temperature. At the same time, when heating the heating liquid, the heating liquid expands and provides a certain pressure to the inner wall of the lip body to balance the pressure on the outer surface of the lip body, avoiding the deformation of the lip body caused by the influence of the external airflow. Description of the Drawings

[0027] Figure 1 It is a front elevation cross-sectional view of a lip structure of an air intake provided in the first embodiment of the present application; Figure 2 It is a front view of a lip structure of an air intake provided in the first embodiment of the present application; Figure 3 It is a cross-sectional view of a lip structure of an air intake provided in the first embodiment of the present application; Figure 4 It is a front view when the lip structure of an air intake provided in the first embodiment of the present application is assembled; Figure 5 It is a simulation schematic diagram of the internal air flow field pressure of a lip structure of an air intake provided in the first embodiment of the present application; Figure 6 It is a simulation schematic diagram of the internal air flow field pressure of an existing conventional lip structure.

[0028] Figure 7 It is a front elevation cross-sectional view of a lip structure of an air intake provided in the second embodiment of the present application; Figure 8 It is a front view of a lip structure of an air intake provided in the second embodiment of the present application; Figure 9 It is a planar schematic diagram of a heating rod of a lip structure of an air intake provided in the second embodiment of the present application; Figure 10 It is a front view when the lip structure of an air intake provided in the second embodiment of the present application is assembled.

[0029] Explanation of reference numerals: 1. Lip body; 11. Outer side wall; 12. Inner side wall; 2. Annular sealing plate; 21. Heating assembly; 211. Heating rod; 212. Electric heating wire; 22. Support member; 221. Support piece; 3. Heating liquid; 4. Air intake. Detailed description of the specific implementation

[0030] The following further describes in detail a lip structure of an air intake and a turboprop engine provided by the present application in conjunction with the attached Figure 1-10 drawings.

[0031] Embodiment 1 Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4, which is a lip structure of an air inlet provided in an embodiment of the present application, including a lip body 1. The lip body 1 is a super-elliptical annular member. The lip body 1 includes a first side wall 11 and a second side wall 12. The first side wall 11 and the second side wall 12 are arranged side by side and bent towards the same side. The first side wall 11 and the second side wall 12 are symmetric about the lip cross-section center line L0. The lip cross-section center line L0 is a curve with a partial super-elliptical shape. The cross-sections of the first side wall 11 and the second side wall 12 are both arc-shaped surfaces with a partial super-elliptical shape. The cross-sectional widths of the first side wall 11 and the second side wall 12 gradually increase in the air inlet direction; Define the shape curve of the outer circle of the lip body (1) as the outer contour curve L1, and the outer contour curve L1 satisfies the formula: where a1 is the major axis length of the outer contour curve L1 in the curve part, b1 is the minor axis length of the outer contour curve L1 in the curve part, m1 is the x-term exponent of the outer contour curve L1, and n1 is the y-term exponent of the outer contour curve L1; Define the shape curve of the inner circle of the lip body (1) as the inner contour curve L2, and the inner contour curve L2 satisfies the formula: a2 is the major axis length of the outer contour curve L2 in the curve part, b2 is the minor axis length of the outer contour curve L2 in the curve part, m2 is the x-term exponent of the outer contour curve L2, and n2 is the y-term exponent of the outer contour curve L2. By setting the lip body 1 with a super-elliptical shape, the lip body 1 is made simpler in design. At the same time, by setting cross-sections with a partial super-elliptical shape on the first side wall 11 and the second side wall 12 of the lip body 1, the curvature of the lip body 1 does not change suddenly, reducing the adverse effects generated by the airflow on the surfaces of the first side wall 11 and the second side wall 12.

[0032] In the related technology, the formula of the super-ellipse can be expressed in the Cartesian coordinate system as: where n, a, and b are positive numbers.

[0033] In this embodiment, the lip cross-section center line L0 also satisfies the formula: where ac is the major axis length of the super-ellipse where the lip cross-section center line L0 is located in the curve part, bc is the minor axis length of the super-ellipse where the lip cross-section center line L0 is located in the curve part, mc is the x-term exponent of the super-ellipse where the lip cross-section center line L0 is located, and nc is the y-term exponent of the super-ellipse where the lip cross-section center line L0 is located.

[0034] Please refer to Figure 2, the lip body 1 further includes two connecting parts 13. The two connecting parts 13 are respectively assembled at both ends of the first side wall 11 and the second side wall 12, and enclose to form the lip body 1. The two connecting parts 13 are continuous with the surface curvatures of the first side wall 11 and the second side wall 12. By providing the connecting parts 13 that are continuous with the curvatures of the first side wall 11 and the second side wall 12, the lip body can be assembled on the air intake passage of the engine, and at the same time, the aerodynamic layout of the lip body 1 can be optimized to reduce air resistance.

[0035] Please refer to Figure 1 , the first side wall 11 includes a first side wall inner surface 111 and a first side wall outer surface 112. The first side wall inner surface 111 and the first side wall outer surface 112 enclose to form the first side wall 11. One side of the first side wall inner surface 111 and the first side wall outer surface 112 are close to each other and are connected to form a connecting contour curve segment L31 having a partial super-elliptical shape; The second side wall 12 includes a second side wall inner surface 121 and a second side wall outer surface 122. The second side wall inner surface 121 and the second side wall outer surface 122 enclose to form the second side wall 12. One side of the first side wall inner surface 11 and the second side wall outer surface 12 are close to each other and are connected to form a connecting contour curve segment L32 having a partial super-elliptical shape. The two ends of the connecting contour curve segment L31 and the connecting contour curve segment L32 are connected end to end to form an annular connecting contour curve L3. The connecting contour curve L3 satisfies the formula: a3 is the major axis length of the outer contour curve L3 in the curve part, b3 is the minor axis length of the outer contour curve L3 in the curve part, m3 is the x-term exponent of the outer contour curve L3, and n3 is the y-term exponent of the outer contour curve L3; The projections of the first side wall inner surface 111 and the second side wall inner surface 121 on the vertical plane are connected to form an inner contour curve L2 having a super-elliptical shape. The ratio C1 of the area of the super-ellipse where the connecting contour curve L3 is located to the area of the super-ellipse where the inner contour curve L2 is located satisfies: 1.1 ≤ C1 ≤ 1.5; The projections of the first side wall outer surface 112 and the second side wall outer surface 122 on the vertical plane are connected to form an outer contour curve L1 having a super-elliptical shape. The ratio C2 of the area of the super-ellipse where the connecting contour curve L3 is located to the area of the super-ellipse where the outer contour curve L1 is located satisfies: 1.1 ≤ C2 ≤ 15; By setting the outer contour curve L1, the inner contour curve L2, and the connecting contour curve L3, the shape and thickness of the lip body 1 can be defined according to the three curves. With fewer parameters involved in the design, the design is more straightforward. At the same time, by setting the ratio of the area of the super-ellipse where the connecting contour curve L3 is located to the area of the super-ellipse where the inner contour curve L2 is located and the ratio of the area of the super-ellipse where the connecting contour curve L3 is located to the area of the super-ellipse where the outer contour curve L1 is located, the contraction ratio between the inner and outer surfaces of the lip body and the intake duct can be regulated, further optimizing the flow field structure and aerodynamic performance of the intake duct, improving the simplicity of the design, and ensuring the aerodynamic performance of the intake duct.

[0036] Please refer to Figure 3 , the cross-sections of the inner surface 111 of the first side wall, the outer surface 112 of the first side wall, the inner surface 121 of the second side wall, and the outer surface 122 of the second side wall are all arc segments with a partial super-ellipse shape. The super-ellipse shapes of the cross-sections of the outer surface 112 of the first side wall and the outer surface 122 of the second side wall are the same, and the super-ellipse shapes of the cross-sections of the inner surface 111 of the first side wall, the inner surface 121 of the second side wall, and the outer surface 112 of the first side wall are different. By using the inner and outer surfaces with two different curvatures to connect and form the first side wall 11 and the second side wall 12, when the air flow reaches the inner surface 111 of the first side wall and the inner surface 121 of the second side wall, no eddy current will occur, thus not affecting the flow field of the air flow in the intake duct. At the same time, the aerodynamic layout of the entire first side wall 11 and the second side wall 12 is optimized, reducing the influence of the swirl on the air flow field and reducing the air resistance it receives.

[0037] Among them, the cross-sectional shape curve of the inner surface 111 of the first side wall is defined as the first inner surface station curve S12, the cross-sectional shape curve of the inner surface 121 of the second side wall is defined as the second inner surface station curve S13, and the cross-sectional shape curves of the outer surface 112 of the first side wall and the outer surface 122 of the second side wall are defined as the outer surface station curve S11.

[0038] In this embodiment, the outer surface station curve S11 satisfies the formula: ate is the major axis length of the super-ellipse where the outer surface station curve S11 is located in the curve part, bte is the minor axis length of the super-ellipse where the outer surface station curve S11 is located in the curve part, ms is the x-term exponent of the super-ellipse where the outer surface station curve S11 is located, and ns is the y-term exponent of the super-ellipse where the outer surface station curve S11 is located; The first inner surface station curve S12 satisfies the formula: Let \(a_t\) be the major axis length of the super-ellipse where the first inner surface standing curve \(S_{12}\) is located in the curved part, \(b_t\) be the minor axis length of the super-ellipse where the first inner surface standing curve \(S_{12}\) is located in the curved part, \(m_{12}\) be the x-term exponent of the super-ellipse where the outer surface standing curve \(S_{11}\) is located, and \(n_{12}\) be the y-term exponent of the super-ellipse where the outer surface standing curve \(S_{11}\) is located; The second inner surface standing curve \(S_{13}\) satisfies the formula: Let \(a_{ts}\) be the major axis length of the super-ellipse where the second inner surface standing curve \(S_{13}\) is located in the curved part, \(b_{ts}\) be the minor axis length of the super-ellipse where the second inner surface standing curve \(S_{13}\) is located in the curved part, \(m_{13}\) be the x-term exponent of the super-ellipse where the outer surface standing curve \(S_{11}\) is located, and \(n_{13}\) be the y-term exponent of the super-ellipse where the outer surface standing curve \(S_{11}\) is located.

[0039] In summary, when the aircraft is in a flight state with a large angle of attack or a large sideslip, due to the more continuous surface curvature of the lip body 1, compared with the lip inner surface determined by a circle or an ellipse, the airflow is less affected, thereby reducing the generation of eddy currents; When the airflow is on the inner surface 111 of the first sidewall of the lip body 1, due to the more continuous curvature of the inner surface 121 of the second sidewall on the other side of the lip body 1, compared with the lip inner surface determined by a circle or an ellipse, the airflow is less affected, thereby reducing the generation of eddy currents. At the same time, for the swirl generated by the propeller, the influence on the inner surface 121 of the second sidewall of the lip body 1 is also reduced, so as to ensure the aerodynamic performance of the subsequent intake duct; Please refer to Figure 5 and Figure 6 . By comparing Figure 5 and Figure 6 , it can be seen that Figure 5 the internal airflow field pressure of the lip structure in Figure 6 is more uniform, and the pressure coefficients at both ends are about 0 to 1, and there will be no low-pressure area. While in

[0040] , that is, for the internal airflow field pressure of the existing conventional lip structure, the pressure difference of the airflow field at both ends is relatively large, and the pressure coefficients at both ends are between -2 and 1. Thus, it can be known that after optimizing the surface shape of the lip body 1 in this application, when the gas passes through the lip body 1, the pressure distribution on the inner sidewall is more uniform, and the flow field entering the lip body 1 is more uniform, thereby effectively improving the aerodynamic performance of the intake duct. In addition, by setting the lip body 1 into a symmetrical super-elliptical shape, the device utilizes the characteristic of fewer super-elliptical design parameters, improves the simplicity of the design, and reduces the manpower.

[0041] Embodiment 2 Please refer to Figure 7 、 Figure 8 、 Figure 9 and Figure 10 , Embodiment 2 is basically the same as Embodiment 1, the difference is that: The lip structure of the intake passage further includes: an annular sealing plate 2 that fits the shape of the lip body 1. The lip body 1 is an annular member with a hollow interior. There is an opening on one side of the lip body 1. The annular sealing plate 2 is sealingly assembled at the opening of the lip body 1. The interior of the lip body 1 is filled with a heating liquid 3. The annular sealing plate 2 is provided with a heating component 21 that can extend into the interior of the lip body 1. By using the heating component 21 that can heat the heating liquid 3, the lip body can, in a low-temperature environment, heat the heating liquid 3 so that the surface of the lip body will not freeze. At the same time, the heating liquid 3 is filled in the lip body 1. Even if the shape of the lip body 1 is special, it can still evenly fill and heat the shape of the lip body 1.

[0042] Please refer to Figure 7 and Figure 8 , the heating component 21 includes a heating rod 211. One end of the heating rod is assembled on the annular sealing plate 2, and the other end extends into the interior of the lip body 1. The heating rod 211 is provided with a cavity extending along its own length direction inside. The cavity is provided with an electric heating wire 212. Among them, the heating rod 211 can be a copper or copper alloy member. The heating rod 211 can increase its own temperature when the electric heating wire 212 is energized and heat up the heating liquid.

[0043] Please refer to Figure 7 , the heating liquid 3 is water or glycerin. By setting the heating liquid 3 with a relatively large coefficient of thermal expansion, it can expand when heated, and use the pressure of the heated and expanded heating liquid on the inner surface of the lip body to balance the air flow pressure on the outer surface of the lip body 1, reducing the occurrence of deformation of the lip body 1 due to the long-term influence of the air flow pressure.

[0044] Please refer to Figure 9, the lip structure of the air inlet further includes a support member 22, the support member 22 includes at least two support pieces 221, at least two of the support pieces 221 are coaxially sleeved on the heating rod 211 and are arranged at intervals along the length direction of the heating rod 211, and the support piece 221 is connected and abutted against the inner wall of the lip body 1. By arranging a plurality of support pieces 221 on the heating rod 211, the device can reduce the material used for the lip body 1, facilitate heating, and ensure the structural strength of the lip body 1 In summary, in a low-temperature environment, the lip body 1 needs to be heated and warmed up. By energizing the heating wire 212, the heating wire 212 generates heat, and the heat is transferred to the heating rod 211, so that the heating rod 211 is heated up, and further heats the heating liquid 3 inside the lip body 1, thereby evenly raising the temperature of the lip body 1 and preventing it from freezing in a low-temperature environment. At the same time, after the heating liquid 3 is heated, it expands itself and generates a pressure on the inner surface of the lip body 1, so as to balance the pressure of the airflow on the outer surface of the lip body 1 to a certain extent, and avoid the lip body 1 from deforming due to the influence of the external airflow pressure for a long time.

[0045] This application also relates to a turboprop engine, and its technical solution is as follows: a turboprop engine includes a lip structure of an air inlet. By arranging the lip structure of the air inlet in the two above-mentioned embodiments on the turboprop engine, the overall aerodynamic effect of the turboprop engine can be improved.

[0046] The above are all the preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. An inlet lip structure, characterized in that: It includes a lip body (1), and the lip body (1) is a super-elliptical annular member. The lip body (1) includes a first side wall (11) and a second side wall (12). The first side wall (11) and the second side wall (12) are arranged side by side and bent to the same side. The first side wall (11) and the second side wall (12) are symmetric about the lip cross-section center line L0, and the lip cross-section center line L0 is a curve with a partial super-elliptical shape. The cross-sections of the first side wall (11) and the second side wall (12) are both arc-shaped surfaces with a partial super-elliptical shape, and the cross-section widths of the first side wall (11) and the second side wall (12) gradually increase in the intake air direction. Define the shape curve of the outer circle of the lip body (1) as the outer contour curve L1, and the outer contour curve L1 satisfies the formula: where a1 is the major axis length of the outer contour curve L1 in the curve part, b1 is the minor axis length of the outer contour curve L1 in the curve part, m1 is the x-term exponent of the outer contour curve L1, and n1 is the y-term exponent of the outer contour curve L1; Define the shape curve of the inner circle of the lip body (1) as the inner contour curve L2, and the inner contour curve L2 satisfies the formula: a2 is the major axis length of the outer contour curve L2 in the curve part, b2 is the minor axis length of the outer contour curve L2 in the curve part, m2 is the x-term exponent of the outer contour curve L2, and n2 is the y-term exponent of the outer contour curve L2.

2. The lip structure of an air intake according to claim 1, characterized in that: The lip body (1) further includes two connecting parts (13). The two connecting parts (13) are respectively assembled at both ends of the first side wall (11) and the second side wall (12) and enclose to form the lip body (1). The surface curvatures of the two connecting parts (13) are continuous with those of the first side wall (11) and the second side wall (12).

3. The lip structure of an air inlet according to claim 2, characterized in that: The first side wall (11) includes a first side wall inner surface (111) and a first side wall outer surface (112). The first side wall inner surface (111) and the first side wall outer surface (112) enclose to form the first side wall (11). One side of the first side wall inner surface (111) and the first side wall outer surface (112) approaches each other and is connected to form a connecting profile curve segment L31 with a partial super-elliptical shape. The second side wall (12) includes a second side wall inner surface (121) and a second side wall outer surface (122). The second side wall inner surface (121) and the second side wall outer surface (122) enclose to form the second side wall (12). One side of the first side wall inner surface (11) and the second side wall outer surface (12) are close to each other and connected to form a connecting contour curve segment L32 with a partial super-elliptical shape. The two ends of the connecting contour curve segment L31 and the connecting contour curve segment L32 are connected end to end to form an annular connecting contour curve L3. The connecting contour curve L3 satisfies the formula: a3 is the major axis length of the outer contour curve L3 in the curve part, b3 is the minor axis length of the outer contour curve L3 in the curve part, m3 is the x-term exponent of the outer contour curve L3, and n3 is the y-term exponent of the outer contour curve L3; The projections of the first side wall inner surface (111) and the second side wall inner surface (121) on the vertical plane are connected to form an inner profile curve L2 with a super-elliptical shape. The ratio C1 of the area of the super-ellipse where the connecting profile curve L3 is located to the area of the super-ellipse where the inner profile curve L2 is located satisfies: 1.1 ≤ C1 ≤ 1.

5.

4. The lip structure of an air intake duct according to claim 3, characterized in that: The projections of the first side wall outer surface (112) and the second side wall outer surface (122) on the vertical plane are connected to form an outer profile curve L1 with a super-elliptical shape. The ratio C2 of the area of the super-ellipse where the connecting profile curve L3 is located to the area of the super-ellipse where the outer profile curve L1 is located satisfies: 1.1 ≤ C2 ≤ 15.

5. The lip structure of an air inlet according to claim 3, characterized in that: The cross-sections of the first side wall inner surface (111), the first side wall outer surface (112), the second side wall inner surface (121), and the second side wall outer surface (122) are all arc-shaped segments with a partial super-elliptical shape. The super-elliptical shapes of the cross-sections of the first side wall outer surface (112) and the second side wall outer surface (122) are the same, and the super-elliptical shapes of the cross-sections of the first side wall inner surface (111), the second side wall inner surface (121), and the first side wall outer surface (112) are different from each other.

6. The lip structure of an air intake according to claim 1, characterized in that: The lip structure of the intake passage further includes an annular sealing plate (2) that fits the shape of the lip body (1). The lip body (1) is an annular member with a hollow interior. One side of the lip body (1) is provided with an opening, and the annular sealing plate (2) is sealingly assembled at the opening of the lip body (1). The interior of the lip body (1) is filled with a heating liquid (3), and a heating component (21) that can extend into the interior of the lip body (1) is provided on the annular sealing plate (2).

7. The lip structure of an air inlet according to claim 6, characterized in that: The heating component (21) includes a heating rod (211). One end of the heating rod (211) is assembled on the annular sealing plate (2), and the other end extends into the interior of the lip body (1). A cavity extending along the length direction of the heating rod (211) is provided inside the heating rod (211), and an electric heating wire (212) is provided inside the cavity.

8. The lip structure of an air inlet according to claim 7, characterized in that: The heating liquid (3) is water or glycerol.

9. The lip structure of an air intake according to claim 7, characterized in that: The lip structure of the intake passage further includes a support member (22). The support member (22) includes at least two support pieces (221). At least two of the support pieces (221) are coaxially sleeved on the heating rod (211) and are spaced along the length direction of the heating rod (211). The support piece (221) is connected and abutted against the inner wall of the lip body (1).

10. A turboprop engine, characterized in that: It includes a lip structure of an intake passage according to any one of claims 1-9.

Images