An air inlet channel and a design method of its transverse guide plate
By adding a transverse deflector inside the intake manifold, the problem of airflow separation at the large-angle bend of the intake manifold was solved, improving airflow uniformity and enhancing engine performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- AVIC (CHENGDU) UAS CO LTD
- Filing Date
- 2023-03-30
- Publication Date
- 2026-06-12
AI Technical Summary
Existing radial intake engines suffer from severe airflow separation at large-angle bends in the intake duct, resulting in poor airflow uniformity and affecting engine performance.
A transverse guide vane is added inside the air intake. The position and shape of the guide vane are determined by numerical simulation calculation to block the airflow from moving from the inside to the outside, forcing the airflow to make a large-angle turn along the guide vane, alleviating airflow separation on the inner wall and improving the uniformity of the flow field.
It effectively suppresses airflow separation on the inner wall of the intake duct, reduces the reverse pressure gradient, improves the flow field uniformity of the AIP surface, and enhances engine performance.
Smart Images
Figure CN116361916B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aircraft technology, and more specifically, to a method for designing a lateral deflector. Furthermore, this invention also relates to an air intake using the aforementioned lateral deflector design method. Background Technology
[0002] The radial intake engine is adapted to the Z-shaped intake duct. There is a large angle turn at the rear of the intake duct, and the end of the intake duct is connected to the air collection device. When the airflow passes through the large angle turn, it is subjected to centrifugal force. The airflow will move from the inside of the duct to the outside of the duct. After being blocked on the outer wall, it flows back to the inside of the duct along both sides of the wall.
[0003] The inward migration of low-speed fluid on the outer wall, coupled with the large-angle turn of the air intake, causes the flow channel to expand and the airflow pressure to rise sharply. The pressure gradient against the flow direction increases, resulting in significant separation of the airflow near the wall and the formation of vortices. This leads to poor uniformity of the airflow entering the gas collection device and a large proportion of low-energy flow areas.
[0004] When the airflow flows within the air intake device, the separation zone expands further, which intensifies the vortex intensity. This leads to enhanced swirl on the AIP surface (Aerodynamic Interface Plane), resulting in poor airflow uniformity and severely impacting engine performance.
[0005] In summary, how to suppress the separation of airflow on the inner wall of the intake duct and the movement of airflow from the inner side of the duct to the outer side is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0006] In view of this, the purpose of the present invention is to provide a transverse guide plate design method, which adds a transverse guide plate in the air intake, and uses the transverse guide plate to block the movement of airflow from the inside of the air intake to the outside of the air intake, forcing the central airflow to make a large-angle turn along the transverse guide plate, while alleviating airflow separation near the inner wall of the air intake, and effectively improving the flow field uniformity of the AIP surface.
[0007] In addition, the present invention also provides an air intake duct that applies the above-described transverse deflector design method.
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] A method for designing a transverse air deflector includes:
[0010] Step S1: Perform numerical simulation calculations on the baseline design of the air intake to obtain the internal flow field data of the air intake.
[0011] Step S2: Determine the starting position of the leading edge of the transverse guide vane based on the internal flow field data of the air intake duct;
[0012] Step S3: Determine the inner and outer profiles of the transverse guide vane so that the inner and outer flow channels of the rear section of the air intake both conform to the area expansion law of equal speed.
[0013] Step S4: Determine the trailing edge position and thickness of the transverse guide vane based on the internal flow field data of the air intake duct;
[0014] Step S5: Perform numerical simulation calculations on the air intake duct equipped with the transverse guide vane to obtain the internal flow field data of the air intake duct for the guide vane scheme.
[0015] Step S6: Calculate the AIP surface swirl intensity index η based on the inlet flow field data of the deflector design. When the AIP surface swirl intensity index η is greater than the preset AIP surface swirl intensity index η0, repeat steps S2-S5.
[0016] in, α2 is the local swirl angle at each point on the AIP surface. For the area on the AIP surface where the absolute value of the swirl angle is greater than 15°, A AIP Let AIP be the area.
[0017] Preferably, step S2 includes the following: the starting position of the leading edge of the transverse guide vane is located in front of the starting position of airflow separation in the internal flow field of the intake duct.
[0018] Preferably, step S3 includes: controlling the area expansion ratio of the inner and outer flow channels in the rear section of the air intake to be less than or equal to 1.6.
[0019] Preferably, step S4 includes the rear edge of the transverse guide vane being located in front of the connection end face of the air intake and the air collection device.
[0020] An air intake, employing the design method of the lateral deflector described in any of the preceding claims, includes an air intake and a lateral deflector disposed at the rear section of the air intake.
[0021] Preferably, the air intake and the transverse guide vane are an integral structure.
[0022] Preferably, the air intake duct is provided with a guide plate mounting groove, the transverse guide plate is inserted into the guide plate mounting groove, a sealing plate is provided outside the air intake duct, and the transverse guide plate and the sealing plate are connected by corner pieces.
[0023] The transverse guide vane design method provided by the present invention first performs numerical simulation on the baseline scheme of the air intake to obtain the internal flow field data of the air intake;
[0024] Then, based on the flow field data inside the intake duct, the starting position of the leading edge of the transverse guide vane is determined. The transverse guide vane is used to block the movement of airflow from the inside of the duct to the outside of the duct and alleviate the airflow separation on the inner wall of the intake duct.
[0025] The inner and outer profiles of the transverse guide vane are determined so that the inner and outer flow channels at the rear end of the intake duct both conform to the area expansion law of equal speed. This forces the central airflow in the intake duct to make a large-angle turn along the transverse guide vane, preventing the central airflow from moving to the outside of the flow channel under the action of centrifugal force, and reducing the area expansion ratio of the inner and outer flow channels, so as to reduce the reverse pressure gradient at the turning point of the intake duct and suppress the airflow separation phenomenon.
[0026] The position and thickness of the trailing edge of the transverse guide vane are determined based on the internal flow field data of the air intake, so that the transverse guide vane can effectively block the movement of airflow from the inside of the flow channel to the outside of the flow channel.
[0027] Then, based on the starting point of the front edge, the inner and outer surfaces, the position point of the rear edge, and the thickness of the transverse guide vane, numerical simulation calculations were performed on the air intake with the transverse guide vane to obtain the internal flow field data of the air intake under the guide vane scheme.
[0028] Finally, the swirl intensity index η of the AIP surface is calculated based on the internal flow field data of the air intake of the deflector scheme, and it is determined whether the transverse deflector meets the design requirements. If it does not meet the requirements, the design parameters of the transverse deflector are iteratively calculated.
[0029] The transverse guide plate design method provided by the present invention adds a transverse guide plate inside the air intake. The transverse guide plate can block the movement of airflow from the inside to the outside of the air intake, force the central airflow to make a large-angle turn along the transverse guide plate, and at the same time alleviate the airflow separation near the inner wall of the air intake, reduce the swirling intensity of the connection end face between the air intake and the air collection device, so as to guide the airflow and improve the flow field uniformity of the AIP surface.
[0030] Meanwhile, the transverse deflector can reduce the area expansion ratio of the inner and outer flow channels of the intake. Compared with the reference intake design without transverse deflectors, it reduces the reverse pressure gradient at the large-angle turning point of the intake, suppresses the generation of airflow splitting and separation, and improves the flow field uniformity of the AIP surface.
[0031] In addition, the present invention also provides an air intake duct that applies the above-described transverse deflector design method. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0033] Figure 1 This is a flowchart illustrating the design method for the transverse guide vane provided by the present invention;
[0034] Figure 2 A streamline diagram of the symmetry plane of the intake duct reference design;
[0035] Figure 3 The streamline diagram of the symmetrical plane of the transverse guide vane scheme;
[0036] Figure 4 A schematic diagram of a specific embodiment of the air intake provided by the present invention;
[0037] Figure 5 This is a schematic diagram of the transverse guide vane structure;
[0038] Figure 6 This is a schematic diagram of the installation of the horizontal guide vane.
[0039] Figures 1-6 middle:
[0040] 1 is the air intake, 2 is the horizontal deflector, 21 is the ear plate, 3 is the sealing plate, and 4 is the corner plate. Detailed Implementation
[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0042] The core of this invention is to provide a design method for a transverse guide vane. A transverse guide vane is added inside the air intake duct to block the movement of airflow from the inside to the outside of the duct, forcing the central airflow to make a large-angle turn along the transverse guide vane. At the same time, it alleviates airflow separation near the inner wall of the air intake duct and effectively improves the flow field uniformity of the AIP surface.
[0043] In addition, the present invention also provides an air intake duct that applies the above-described transverse deflector design method.
[0044] Please refer to Figures 1-6 , Figure 1This is a flowchart illustrating the design method for the transverse guide vane provided by the present invention; Figure 2 A streamline diagram of the symmetry plane of the intake duct reference design; Figure 3 The streamline diagram of the symmetrical plane of the transverse guide vane scheme; Figure 4 A schematic diagram of a specific embodiment of the air intake provided by the present invention; Figure 5 This is a schematic diagram of the transverse guide vane structure; Figure 6 This is a schematic diagram of the installation of the horizontal guide vane.
[0045] The transverse guide vane design method provided by this invention includes:
[0046] Step S1: Perform numerical simulation calculations on the baseline scheme of intake duct 1 to obtain the internal flow field data of the intake duct;
[0047] Step S2: Determine the starting position of the leading edge of the transverse guide vane 2 based on the internal flow field data of the air intake duct;
[0048] Step S3: Determine the inner and outer profiles of the transverse guide vane 2 so that both the inner and outer flow channels in the rear section of the intake duct conform to the area expansion law of equal speed.
[0049] Step S4: Determine the trailing edge position and thickness of the transverse guide vane 2 based on the internal flow field data of the air intake duct;
[0050] Step S5: Perform numerical simulation calculations on the air intake 1 equipped with the transverse guide vane 2 to obtain the internal flow field data of the air intake 1 with the guide vane scheme.
[0051] Step S6: Calculate the AIP surface swirl intensity index η based on the inlet flow field data of the guide vane design. If the AIP swirl intensity index η is greater than the preset AIP swirl intensity index η0, repeat steps S2-S5.
[0052] in, α2 is the swirl angle at each point on the AIP surface. For the area on the AIP surface where the absolute value of the swirl angle is greater than 15°, A AIP Let AIP be the area.
[0053] It should be noted that the reference scheme of the air intake duct 1 includes the flow channel shape and size of the air intake duct 1, so as to perform numerical simulation calculations on the reference scheme using common numerical simulation software and obtain the internal flow field data of the air intake under the reference scheme.
[0054] The inlet flow field data for the baseline scheme can be either a three-dimensional flow field diagram or... Figure 2 , Figure 3 The streamline diagram shown can also be vorticity data, velocity distribution data, pressure distribution data, etc.
[0055] It should be noted that in order to suppress the airflow separation phenomenon in the flow channel, the starting point of the leading edge of the transverse guide plate 2 should be located in front of the starting point of airflow separation in the flow field inside the intake channel.
[0056] Meanwhile, to avoid the transverse guide plate 2 being too long, the starting point of the leading edge of the transverse guide plate 2 should be as close as possible to the starting point of airflow separation.
[0057] It should be noted that in order to prevent the airflow injection angle from being too large and causing airflow separation, the starting angle of the inner and outer surfaces of the front edge of the transverse guide plate 2 is less than or equal to 10° with the local airflow direction.
[0058] The cross-sectional shape of the transverse guide vane 2 is not unique. Depending on the thickness from the leading edge of the guide vane to the thick edge of the guide vane, the transverse guide vane 2 can be specifically set as equal thickness, thick-thin, thin-thick, thin-thick-thin, airfoil, etc.
[0059] In order to improve the distortion of the flow field on the AIP surface and enhance the uniformity of the flow field, preferably, the area expansion ratio of the inner and outer flow channels in the rear section of the inlet 1 can be controlled to be less than 1.6, so as to limit the reverse pressure gradient of the airflow and suppress the airflow separation phenomenon.
[0060] It should be noted that the trailing edge of the transverse guide plate 2 is located in front of the connection end face between the air intake and the air collection device. The closer the trailing edge of the transverse guide plate 2 is to the connection end face between the air intake and the air collection device, the smaller the airflow mixing loss between the inner and outer channels and the influence of the wake flow at the trailing edge of the transverse guide plate 2.
[0061] However, the closer the trailing edge of the transverse guide plate 2 is to the connection end face between the air intake and the air collection device, the more difficult it is to install the transverse guide plate 2. Therefore, it is necessary to comprehensively consider the installation difficulty and flow loss to determine the trailing edge position of the transverse guide plate 2.
[0062] Regarding the thickness of the transverse guide vane 2, an excessively thin guide vane at the trailing edge is difficult to achieve in engineering, while an excessively thick guide vane at the trailing edge can easily lead to aerodynamic separation of the airflow, affecting the flow field uniformity of the AIP surface. Therefore, the thickness of the transverse guide vane 2 needs to be determined by comprehensively considering the above two factors.
[0063] It is necessary to explain step S5 that, based on the design parameters such as the front and rear edge positions, thickness, and left and right side profiles of the transverse guide vane 2 obtained in steps S2-S4, numerical simulation calculations are performed on the transverse guide vane scheme of the intake duct 1 to obtain the internal flow field data of the intake duct of the guide vane scheme. The internal flow field data of the intake duct of the guide vane scheme includes the local flow velocity at each point in the intake duct.
[0064] To facilitate a qualitative assessment of the guiding effect of the transverse guide vane 2 on airflow, numerical simulation can also be used to calculate the production process, such as... Figure 3 The streamline diagrams of the symmetrical plane and other internal streamline diagrams of the air intake are shown. The airflow distribution within the symmetrical plane is used to judge the improvement of the uniformity of the flow field on the AIP surface by the added transverse guide plate 2.
[0065] It should be noted that in step S6, the preset AIP surface swirl intensity index η0 is determined by the engine design's intake swirl angle requirements, etc. Based on this, it is determined whether the design parameters of the transverse guide plate 2 meet the engine's intake requirements. If they still do not meet the requirements, the design parameters of the transverse guide plate 2 are iteratively calculated through steps S2-S5.
[0066] The local swirl angle α2 of the AIP surface is equal to arctan(V). θ / V y ),
[0067] Among them, V θ V is the tangential velocity of the airflow at the AIP surface. y denoted as axial velocity of the airflow perpendicular to the AIP surface.
[0068] Considering that the AIP surface is close to the guide vanes inside the gas collection device, and that the boundary layer and wake flow exist simultaneously on the cross section, the airflow direction is disturbed. The local swirl angle α2 cannot accurately characterize the swirl intensity of the AIP surface. Therefore, the area percentage η with a local swirl angle absolute value exceeding 15° is used as the swirl intensity index of the AIP surface.
[0069] In this embodiment, a transverse guide plate 2 is added inside the air intake duct 1. The transverse guide plate 2 can block the movement of airflow from the inside of the duct to the outside of the duct, force the central airflow to make a large-angle turn along the transverse guide plate 2, and at the same time alleviate the airflow separation near the inner wall of the air intake duct, reduce the swirling intensity of the connection end face between the air intake duct and the air collection device, so as to guide the airflow and improve the flow field uniformity of the AIP surface.
[0070] Meanwhile, the transverse guide vane 2 can reduce the area expansion ratio of the inner and outer flow channels of the intake duct 1. Compared with the reference intake duct scheme without transverse guide vane 2, it reduces the reverse pressure gradient at the intake duct turning point, suppresses the generation of airflow splitting and separation, and improves the flow field uniformity of the AIP surface.
[0071] In a specific embodiment, the streamline diagram of the symmetry plane of the air intake 1 under the reference scheme is as follows: Figure 2 As shown, the maximum swirl angle α at the AIP surface 2，max The angle is 35°, and the AIP surface swirl intensity index η is 30%; the streamline diagram of the symmetrical plane of the transverse guide plate scheme with added transverse guide plate 2 is as follows. Figure 3 As shown, the maximum swirl angle α at the AIP surface 2，maxWith an angle of 30° and an AIP surface swirl intensity index η of 20%, the flow field uniformity of the AIP surface is greatly improved, meeting the engine's intake swirl requirements.
[0072] In addition to the above-mentioned transverse guide vane design method, the present invention also provides an air intake duct that applies the transverse guide vane design method disclosed in the above embodiments. The air intake duct includes an air intake duct 1 and a transverse guide vane 2 disposed at the rear section of the air intake duct 1. The structure of other parts of the air intake duct 1 can be referred to the prior art, and will not be described in detail here.
[0073] Regarding the connection method between the transverse guide plate 2 and the air intake 1, the air intake 1 and the transverse guide plate 2 can be set as an integral structure and manufactured by integral 3D printing; or the two can be designed and manufactured separately and then connected.
[0074] Preferably, the air intake duct 1 is provided with a guide plate mounting groove, the transverse guide plate 2 is inserted into the guide plate mounting groove, and a sealing plate 3 is provided outside the air intake duct 1. The transverse guide plate 2 and the sealing plate 3 are connected by a corner piece 4.
[0075] The materials, structures, and dimensions of the transverse guide plate 2, sealing plate 3, and corner plate 4 are determined based on the actual production needs and with reference to existing technologies, and will not be elaborated here.
[0076] Please refer to Figure 5 and Figure 6 Each of the four corners of the transverse guide plate 2 is provided with a lug 21. During assembly, the transverse guide plate 2 is first inserted into the guide plate mounting groove of the air intake duct 1. Then, a corresponding sealing plate 3 is set on the outside of the air intake duct 1 to prevent air leakage from the air intake duct 1. Finally, the sealing plate 3 and the transverse guide plate 2 are fixedly connected by the corner piece 4 to prevent the transverse guide plate 2 from falling off.
[0077] Of course, the transverse guide plate 2 can also be connected to the intake duct 1 by means of adhesive bonding, welding, bolting, etc.
[0078] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0079] The design method for the air intake duct and its transverse guide vane provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.
Claims
1. A method for designing a transverse guide vane, characterized in that, include: Step S1: Perform numerical simulation calculations on the baseline design of the air intake to obtain the internal flow field data of the air intake. Step S2: Determine the starting position of the leading edge of the transverse guide vane based on the internal flow field data of the air intake duct; Step S3: Determine the inner and outer profiles of the transverse guide vane so that the inner and outer flow channels of the rear section of the air intake both conform to the area expansion law of equal speed. Step S4: Determine the trailing edge position and thickness of the transverse guide vane based on the internal flow field data of the air intake duct; Step S5: Perform numerical simulation calculations on the air intake duct equipped with the transverse guide vane to obtain the internal flow field data of the air intake duct for the guide vane scheme. Step S6: Calculate the AIP surface swirl intensity index based on the internal flow field data of the air intake of the deflector design. When the AIP surface swirl intensity index Greater than the preset AIP surface swirl intensity index Then, repeat steps S2-S5. in, , The local swirl angle at each point on the AIP surface. For areas on the AIP surface where the absolute value of the swirl angle is greater than 15°, The area of AIP; Step S3 includes controlling the area expansion ratio of the inner and outer flow channels in the rear section of the air intake to be less than or equal to 1.
6.
2. The transverse guide vane design method according to claim 1, characterized in that, Step S2 includes the following: the starting position of the leading edge of the transverse guide vane is located in front of the starting position of airflow separation in the internal flow field of the intake duct.
3. The transverse guide vane design method according to claim 1, characterized in that, Step S4 includes the rear edge of the transverse guide plate being located in front of the connection end face between the air intake and the air collection device.
4. An air intake duct, employing the design method of the transverse guide vane according to any one of claims 1-3, characterized in that, It includes an air intake and a transverse deflector located at the rear of the air intake.
5. The air intake duct according to claim 4, characterized in that, The air intake and the lateral deflector are an integral structure.
6. The air intake duct according to claim 4, characterized in that, The air intake is provided with a guide plate mounting groove, the transverse guide plate is inserted into the guide plate mounting groove, a sealing plate is provided outside the air intake, and the transverse guide plate and the sealing plate are connected by corner pieces.