Single-degree-of-freedom multivariable coupling regulation wide-speed-domain internal rotation adjustable air inlet channel

Abstract

The invention discloses a single-degree-of-freedom multivariable coupling regulation wide-speed-range inner rotation adjustable air inlet channel. The air inlet channel mainly comprises a fixed wave rider front body, an integrated mechanism of a sweepback lip mask and a side plate capable of moving front and back, and a fixed isolation section. The thought for achieving wide speed range regulation and control of the air inlet channel is that under the low Mach number working condition, an integrated mechanism of a lip cover and a side plate moves forwards in the incoming flow direction, the shrinkage ratio of the air inlet channel is reduced, meanwhile, the area of a drainage seam between a compression section and an isolation section is increased, airflow choked in a throat channel is discharged through a sweepback lip and the drainage seam, and the aerodynamic performance of the air inlet channel is improved; when the Mach number of incoming flow is high, the integrated mechanism moves backwards, the contraction ratio of the compression section is increased, the area of the drainage seam is reduced, and the compression performance of the air inlet channel is improved while the final capture flow is guaranteed; under the working condition of the highest design Mach number, the integrated mechanism is located at the rear limit position, at the moment, the drainage seam is closed, and the throat section is the isolation section inlet section.

Description

TECHNICAL FIELD

[0001] The application discloses a single-freedom multi-variable coupling regulation and control wide-speed-range internal turning inlet design method, and belongs to the field of inlet aerodynamic design and flow field control. BACKGROUND

[0002] The inlet is one of the key components of the air-breathing propulsion system, and its main function is to continuously and stably provide the downstream engine with gas with certain pressure, temperature and speed. Common supersonic inlets mainly include binary, axisymmetric and side pressure inlets, which have respective advantages and disadvantages and are suitable for aircrafts. In recent years, a three-dimensional internal turning inlet based on the internal waverider theory has attracted extensive attention from researchers, and has become the preferred scheme for high-Mach-number aircrafts due to its unique advantages different from traditional inlets, mainly including high compression efficiency, good internal flow quality, small spillage drag, strong flow capture capacity and easy integration design.

[0003] However, the current problem of the hypersonic aircraft is how to realize stable operation in a wide Mach number range, and the inlet, as one of the key components, also has a narrow stable operation range. In particular, for the three-dimensional internal turning inlet with a high Mach number as a design point, the performance is poor in the low Mach number working condition, and the inlet is prone to not starting, causing engine surge. In order to widen the stable operation range of the inlet and improve the aerodynamic performance at non-design points, a variable geometry mechanism is usually required.

[0004] The internal turning inlet has a three-dimensional compression effect, and the variable geometry schemes commonly used for the binary inlet, such as the adjustable compression face angle, and the axisymmetric inlet, such as the adjustable center cone position, are not applicable to the internal turning inlet. Therefore, it is necessary to design a simple, stable and applicable variable geometry scheme for the internal turning inlet. SUMMARY

[0005] In view of the deficiencies of the common variable geometry schemes of the inlet, the application provides a single-freedom multi-variable coupling regulation and control wide-speed-range internal turning inlet design method, which is used for realizing synchronous and same-direction adjustment of shock closure and flow matching in a working Mach number range, and solving the problems of throat flow congestion at a low incoming flow Mach number and low compression efficiency at a high incoming flow Mach number.

[0006] To achieve the above object, the single-freedom multi-variable coupling regulation and control wide-speed-range internal turning inlet of the application comprises three components: a waverider forebody, an integrated mechanism of a swept back cowl and a side plate and a isolator. The waverider forebody and the isolator mechanism are fixed, and the integrated mechanism of the cowl and the side plate can move forward and backward along the incoming flow direction.

[0007] The integrated mechanism of the lip cover and the side plate adopts a half profile design, is connected through fasteners, and is provided with a bottom plate and a guide rail sliding block mechanism on both sides, the bottom plate is connected with the upper and lower parallel double guide rail sliding block mechanisms, the tail of the integrated mechanism of the lip cover and the side plate is connected with a stepping motor rod or an electric steel rod through a Y-shaped transmission component, and under the driving of the power mechanism, the integrated mechanism moves forward and backward along the guide rail.

[0008] Further, the isolation section also adopts a half profile design, is connected through fasteners from left to right, is connected with the front and rear of the drum front body respectively, and is connected with the bottom plate from top to bottom.

[0009] Further, the integrated mechanism of the lip cover and the side plate adopts a double-section design, the front half part is a compression section of an inverted internal turning air inlet, is used for decelerating and pressurizing the airflow, and the rear half part is cooperatively designed with the wave-riding front body, is a channel with an equal cross section or a slightly expanded cross section, and plays a role of flow regulation on the gas downstream of the throat.

[0010] Further, there is an area-adjustable leakage slot between the integrated mechanism of the lip cover and the side plate and the isolation section, the leakage slot is used for discharging excess gas under a low Mach number condition, and prevents the throat from being blocked.

[0011] Further, the front half part of the integrated mechanism of the lip cover and the side plate adopts a single-degree-of-freedom variable configuration, the contraction ratio of the air inlet is adjusted through the single-degree-of-freedom variable configuration, and it is ensured that the front body shock wave is always in a sealed state in a working speed range.

[0012] Further, when working at a low airflow Mach number, the integrated mechanism of the lip cover and the side plate moves forward along the airflow direction, ensures that the front body shock wave is in a sealed state, at this time, the contraction ratio is small, and the throat area is large, has a positive effect on the starting of the air inlet, and simultaneously, due to the large area of the leakage slot, the blocked airflow is discharged, and the starting performance of the air inlet under a low Mach number is improved; when the flight Mach number gradually increases, the single-degree-of-freedom variable configuration gradually moves backward, the contraction ratio gradually increases, and the area of the leakage slot gradually decreases, synchronous and same-direction adjustment of the shock wave sealing and the flow matching is realized, and the compression performance under a high Mach number condition and the flow demand are ensured.

[0013] The beneficial effects of the present application relative to the prior art are:

[0014] The application has simple mechanism and strong feasibility, and multiple variable coupling regulation can be realized by moving the integrated mechanism of the lip and the side plate along the flow direction, and the working range of the internal turning inlet is widened. The forward and backward movement of the integrated mechanism can realize stepless adjustment of the contraction ratio of the inlet, so as to meet the compression performance of the inlet under each Mach number condition; the backward sweep design of the side plate and the design of the internal pressure section discharge slot not only have a positive relief effect on the flow congestion problem of the inlet under the low Mach condition, but also can discharge low-energy flow to reduce the shock boundary layer interference and improve the aerodynamic performance; the stepless adjustable integrated moving mechanism can accurately control the distance between the leading edge shock wave and the lip under each incoming flow Mach number, and the size of the discharge slot area can be adjusted to ensure that the flow capture of the inlet meets the actual demand of the downstream engine. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the symmetric plane view of the variable geometry inlet aerodynamic shape of the embodiment of the application when the incoming flow is Ma3

[0016] Figure 2 is the symmetric plane view of the variable geometry inlet aerodynamic shape of the embodiment of the application when the incoming flow is Ma6

[0017] Figure 3 is the symmetric plane view of the variable geometry inlet aerodynamic shape of the embodiment of the application when the incoming flow is Ma10

[0018] Figure 4 is the sectional view of the variable geometry inlet wind tunnel test model of the embodiment of the application

[0019] Figure 5 is the local connection diagram of the variable geometry inlet wind tunnel test model of the embodiment of the application

[0020] Figure 6 is the overall structure diagram of the variable geometry inlet wind tunnel test model of the embodiment of the application

[0021] Figure 7 is the linear law diagram of the total contraction ratio CR (CR=A c / A th ) of the inlet changing with the dimensionless parameter (X cowl / D e ) of the moving distance of the variable geometry mechanism

[0022] The meanings of the marks in the drawings are as follows:

[0023] 1-bulge leading edge, 2-integrated mechanism of the lip cover and the side plate, 3-isolation section, 4-Y-shaped transmission connection component, 5-guide rail slider mechanism, 6-bulge rear side section, 7-bottom plate, A-leading edge shock wave, B-inlet flow, C-discharge flow of the discharge slot, D-outlet flow of the inlet, A c represents the inlet capture area, Ath Indicates the intake throat area, X cowl Indicates the moving distance of the variable geometry mechanism (taking the position of the integrated mechanism under Ma2 working condition as the starting point, see Figure 1 , moving backward then X cowl The value gradually increases), D e Indicates the height of the inlet duct outlet section. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in 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, not all embodiments. Based on the embodiments of the present invention, other embodiments obtained by ordinary technicians in this field without making any creative work are all within the scope of protection of the present invention.

[0025] The present application is a wide-speed range inward-rotating adjustable air inlet with single-degree-of-freedom multi-variable coupling control. The air inlet is an inward-rotating air inlet with variable geometry configuration, mainly composed of three parts, namely a fixed waverider front body (bulge front body), a movable, swept-back lip cover and side panel integrated component, and a (variable cross-section) isolation section with a reasonable offset set according to the requirements of the air inlet outlet.

[0026] The waverider forerunner (bulge forerunner) has a slide groove, which allows the integrated lip cover and swept side panels to move along a preset trajectory; the integrated lip cover and swept side panels are embedded in the aircraft fuselage through the slide groove of the bulge forerunner, and can move along the slide groove driven by a motor or electric steel; the (variable cross-section) isolation section is connected to the forerunner, and there is a drainage channel between the integrated lip cover and the side panel mechanism, and the area of ​​the drainage channel is determined by the relative position of the integrated lip cover.

[0027] Furthermore, driven by a motor (electric steel), the integrated lip and side panel components move along the chute, not only achieving a predetermined change in the inlet contraction ratio to prevent inlet malfunction caused by flow congestion in the internal pressure section, but also creating a venting slot of varying size in the inlet cross-section of the isolation section, allowing excess airflow to be discharged to meet the engine's flow requirements under different operating conditions. Furthermore, the changing position of the lip under varying Mach numbers allows for perfect alignment with the forebody shock wave, thereby increasing flow capture.

[0028] Specifically, the position of the movable integrated lip and swept side plates relative to the body can be adjusted along the streamline direction according to the inclination angle of the forebody shock wave at different incoming Mach numbers and the requirement of the target flow capture of the inlet entrance. When the incoming Mach number is the highest in the design speed range, the movable mechanism is located at the most rear position along the flow direction, at this time, the upper wall surface of the smallest section of the movable lip completely matches the upper wall surface of the entrance section of the isolation section, and there is no leakage slot in the internal flow passage; as the incoming Mach number decreases, in order to ensure that the forebody shock wave is well sealed, the movable mechanism gradually moves forward, and the moving distance is determined by the position of the forebody shock wave. As the movable lip moves forward, the distance between the upper wall surface of the isolation section entrance section and the upper wall surface of the movable lip gradually increases, and then a leakage slot is formed. The increase of the area of the leakage slot can discharge excess airflow, so as to solve the problem of throat choke at low incoming Mach number. When the incoming Mach number decreases to the lowest point in the design speed range, the movable lip is located at the front limit position along the flow direction, at this time, the contraction ratio of the inlet is small, and part of the airflow flowing into the compression section overflows from the leakage port, which can ensure the successful start of the inlet.

[0029] The specific application of the single-degree-of-freedom multi-variable coupling regulation wide-speed-range internal turning adjustable inlet of the application will be described in detail below:

[0030] The working range of the inlet of the embodiment of the application is Ma2-Ma10, the design point is Ma6, and the minimum starting Mach number is Ma2. The inlet mainly consists of three parts, and the aerodynamic shape can be seen from the accompanying drawings Figure 1 -attached Figure 3 , in which: the bulge forebody 1, the integrated mechanism of the lip and the side plate 2, and the isolation section 3, wherein the bulge forebody and the isolation section are fixed, the integrated mechanism of the lip and the side plate adopts swept design, and can move forward and backward along the flow direction.

[0031] For the above aerodynamic shape, the specific model of the inlet is obtained in the wind tunnel test, and the structure of the inlet model is shown in the accompanying drawings Figure 4 ~attached Figure 6 . As can be seen from the accompanying drawings Figure 4 , the integrated mechanism of the lip and the side plate adopts a half-section design and is connected left and right through fasteners, and the bottom of the two side plates can be connected up and down with a parallel double-rail slider mechanism, and the guide rail is fixed to the bottom plate through screws. The tail of the integrated mechanism can be connected to a stepping motor rod or an electric steel rod through a Y-shaped transmission component, and under the drive of the power mechanism, it can move forward and backward along the guide rail, as shown in the accompanying drawings Figure 5 . The isolation section also adopts a half-section design, which is first connected left and right through fasteners, and then connected front and back with the bulge forebody and connected up and down with the bottom plate. In order to ensure the rationality of the processing and installation of the test model, the aerodynamic shape Figure 1 ~attached Figure 3The bulge precursor in the middle is split into three pieces during the actual modeling process, including the main bulge precursor part and two conformal bulge rear section parts, which can be seen in detail from Figure 6 The three bulge precursor parts are fastened to the bottom plate through upper and lower connections.

[0032] Further, the integrated mechanism of the lip cover and the side plate realizes the functions of compressed airflow and flow regulation. The front half of the structure is an inverted fan-shaped capture-shaped inner turning inlet, which cooperates with the bulge precursor to present a converging profile, thereby playing a role in compressing the airflow; the rear half cooperates with the bulge precursor for design, and is basically an equal cross-section or slightly expanding cross-section channel, thereby playing a role in flow regulation.

[0033] The Figure 1 is a variable geometry inlet aerodynamic profile symmetric surface view when the Ma3 airflow arrives. At this working condition, the precursor shock wave A can just hit the lip cover leading edge, and the airflow B flowing into the inlet is divided into two parts after compression and regulation, one of which is discharged from C by the bleed slot, and the other is discharged from D after flowing into the isolation section. At this time, the total contraction ratio of the inlet is small, which can reduce the loss as much as possible under the condition of ensuring a certain compression amount, and the bleed slot area is large, which can discharge the excess airflow to ensure the successful starting of the inlet.

[0034] The Figure 2 is a variable geometry inlet aerodynamic profile symmetric surface view when the Ma6 airflow arrives. At this time, the integrated mechanism of the lip cover and the side plate moves a distance along the flow direction compared with the Ma3 working condition. With the increase of the incoming airflow Mach number, the rearward movement of the variable geometry mechanism can be controlled to always ensure that the precursor shock wave A hits the lip position, which can increase the flow coefficient as much as possible and reduce the shock wave interference at the lip, thereby playing a positive role in improving the flow field structure. During the rearward movement of the lip and the side plate integrated mechanism, the inlet contraction ratio gradually increases, as shown in the Figure 7 , and the regulation section gradually decreases to meet the compression effect of the high Mach number airflow. At the same time, the bleed slot area is always decreasing, and most of the airflow captured by the inlet flows out from the isolation section outlet to ensure the flow demand of the downstream core engine.

[0035] The Figure 3 is a variable geometry inlet aerodynamic profile symmetric surface view when the Ma10 airflow arrives. At this time, the integrated mechanism of the lip cover and the side plate continues to move along the flow direction compared with the Ma6 working condition. This is the limit state of the rearward movement position of the variable geometry mechanism, at which time there is no regulation section in the internal flow passage, the minimum cross section of the compression section is the isolation section inlet cross section, and the bleed slot is in a completely closed state. The super-high Mach number airflow enters the internal flow passage after being compressed by the precursor shock wave A, and then is decelerated and pressurized by the lip reflection shock wave and various reflection shock waves in the internal flow passage, and finally flows out of the inlet from the isolation section outlet to enter the downstream engine.

[0036] The advantage of the present application is that by simply moving the lip and the side plate forward and backward, the air inlet channel contraction ratio is steplessly adjusted, the flow choking problem in low Mach number working condition and the compression performance problem in high Mach number working condition are solved while the lip and the precursor shock wave are accurately matched in a wide working Mach number range.

[0037] The above-mentioned embodiment of the present application is only one special case of the present application, and aims to explain the wave system adjustment and flow field adjustment principle of the lip and side plate integrated variable geometry mechanism, and proves the feasibility of the stepless adjustable device. Therefore, any modification according to the technical idea proposed in the present application or on the basis of the technical scheme falls within the protection scope of the present application.

Claims

1. A single degree of freedom, multivariable coupled, regulated, wide speed range, in-transit adjustable inlet duct, characterized by, The air inlet channel comprises three components: a wave-riding forebody, an integrated mechanism of a swept-back lip cover and side plate, and a separation section. The wave-riding forebody and the separation section mechanism are fixed, and the integrated mechanism of the lip cover and the side plate can move forward and backward along the airflow direction; The integrated mechanism of the lip cover and the side plate adopts a half-section design, is connected through fasteners, and is provided with a bottom plate and a guide rail sliding block mechanism on both sides. The bottom of the plate is connected to the parallel double guide rail sliding block mechanism in an up-down manner. The tail of the integrated mechanism of the lip cover and the side plate is connected to a stepping motor rod or an electric steel rod through a Y-shaped transmission component. Under the driving of the power mechanism, the integrated mechanism moves forward and backward along the guide rail.

2. The single degree of freedom multivariable coupled regulated wide speed range in- turning adjustable inlet duct according to claim 1, wherein, The separation section also adopts a half-section design, is connected through fasteners, and is connected to the wave-riding forebody in front and back and to the bottom plate in an up-down manner.

3. The single degree of freedom multivariable coupled regulated wide speed range in- turning adjustable inlet duct of claim 1, wherein, The integrated mechanism of the lip cover and the side plate adopts a double-section design. The front half part is a compression section of an inverted internal turning air inlet channel, which is used for decelerating and pressurizing the airflow. The rear half part is designed in cooperation with the wave-riding forebody to be a channel with an equal cross section or a slightly expanded cross section, which functions to straighten the gas downstream of the throat.

4. The single degree of freedom multivariable coupled regulated wide speed range in- turning adjustable inlet duct of claim 3, wherein, There is an area-adjustable leakage slot between the integrated mechanism of the lip cover and the side plate and the separation section. The leakage slot is used to discharge excess gas under low Mach number conditions to prevent the throat from being blocked.

5. The single degree of freedom multivariable coupled regulated wide speed range in-rotating adjustable inlet duct according to any one of claims 1 to 4, characterized in that, The front half part of the integrated mechanism of the lip cover and the side plate adopts a single-degree-of-freedom variable configuration, which adjusts the contraction ratio of the air inlet channel and ensures that the forebody shock wave is always in a sealed state within the working speed range.

6. The single degree of freedom multivariable coupled regulated wide speed range in- turning adjustable inlet duct according to claim 5, wherein, When working at a low airflow Mach number, the integrated mechanism of the lip cover and the side plate moves forward along the airflow direction to ensure that the forebody shock wave is in a sealed state. At this time, the contraction ratio is small, and the throat area is large, which has a positive effect on the starting of the air inlet channel. At the same time, due to the large area of the leakage slot, the blocked airflow is discharged, and the starting performance of the air inlet channel at a low Mach number is improved. When the flight Mach number gradually increases, the single-degree-of-freedom variable configuration gradually moves backward, the contraction ratio gradually increases, and the area of the leakage slot gradually decreases, realizing synchronous and same-direction adjustment of shock wave sealing and flow matching, and ensuring the compression performance and flow demand under high Mach number conditions.

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