An inlet duct experimental device

Abstract

The present application belongs to the technical field of inlet experiment, and in particular, relates to an inlet experiment device for testing total pressure distortion and / or swirl distortion of an inlet, specifically, along a flow direction of a flow field, the inlet experiment device comprises a wind tunnel, an inlet, a second measuring section for measuring flow field distortion at an outlet position of the inlet, and a nozzle or compressor test bed arranged after the second measuring section; the inlet is a complex geometric configuration inlet, and the inlet is a full-size model or a scaled-down model. The present application can study flow field characteristics under multiple groups of different geometric shapes of inlets, directly measure and obtain total pressure and swirl distortion coupled flow fields generated by complex geometric inlets, and facilitate research on influences of the existence of the inlet on steady-state and dynamic characteristics of compressors and entire engines in the research and study stage of aero-engines.

Description

Technical Field

[0001] This invention belongs to the field of air intake experimental technology, and more specifically, this invention relates to an air intake experimental device. Background Technology

[0002] The trend towards stealth in military aircraft makes the design of air intakes particularly important. The complex, curved geometry of an S-shaped air intake can cause radar waves to attenuate multiple times on the inner wall of the intake, effectively shielding the engine's visible area and significantly improving the aircraft's stealth performance.

[0003] However, due to the complex geometry and large curvature of the S-shaped air intake, boundary layer separation may occur within the air intake, and total pressure distortion and swirling distortion may occur at the engine inlet downstream, which seriously endangers flight safety and engine life.

[0004] Therefore, to conduct measurements of the intake airflow field at the intake duct inlet and compressor inlet under real intake duct conditions, compressor characteristic tests, and engine steady-state and dynamic performance tests, a practical experimental rig capable of simulating compressor intake distortion caused by an S-shaped intake duct is needed.

[0005] Currently, after connecting to a complex geometry inlet, the typical intake conditions for aero-engines involve the coupling of swirling distortion and total pressure distortion. Existing technologies that simultaneously consider both total pressure distortion and swirling distortion primarily combine techniques for simulating total pressure distortion separately with techniques for simulating swirling distortion separately, thus achieving the effect of coupling the two distortions. While this combined approach can obtain the coupled flow field, it cannot directly determine the specific configuration of the distortion generator after connecting to a complex geometry inlet. The resulting distortion characteristics are difficult to accurately reproduce the steady-state and unsteady-state distortion characteristics of the downstream compressor inlet flow field caused by both the inlet inlet airflow inhomogeneity and the complex geometry of the inlet. Furthermore, the presence of the inlet cavity may alter the stability characteristics of the overall system formed by the inlet and engine, which cannot be considered in the aforementioned technical solutions. Summary of the Invention

[0006] To at least partially solve the above problems, the present invention provides an air intake experimental device, the technical solution of which is as follows:

[0007] An inlet duct experimental apparatus is provided for testing the total pressure distortion and / or swirling distortion of an inlet duct. Along the flow path, the inlet duct experimental apparatus includes a wind tunnel, an inlet duct, a second measurement section for measuring the flow field distortion at the outlet of the inlet duct, and a nozzle or compressor test bench located after the second measurement section. The inlet duct is an inlet duct with a complex geometric configuration, and the inlet duct is a full-size model or a scaled-down model.

[0008] The air intake experimental apparatus described above is further preferably provided with a plurality of pressure sensors distributed along the flow direction of the air intake, the pressure sensors being used to measure the static pressure distribution of the flow field within the air intake; the plurality of pressure sensors are disposed on the upper and / or lower wall surfaces of the air intake.

[0009] The air intake experimental apparatus described above is further preferably provided with a first measurement section between the wind tunnel and the air intake, the first measurement section being used to measure the flow field at the inlet position of the air intake.

[0010] The intake duct experimental apparatus described above is further preferably characterized in that: both the first measurement section and the second measurement section include a probe and a probe holder for mounting the probe; a plurality of probe holders are evenly distributed circumferentially along the corresponding first measurement section or second measurement section, one end of the probe holder is fixed to the inner wall of the corresponding first measurement section or second measurement section, and the other end of the probe holder extends toward the center point of the corresponding first measurement section or second measurement section; at least one probe is provided on each probe holder, and when a plurality of probes are provided on a probe holder, each probe is distributed along the direction from one end of the probe holder to the other end.

[0011] The inlet test apparatus described above is further preferably characterized in that: the probe support is shaped like an aero-engine compressor blade; each probe support has a probe installed at the same radial position; when multiple probes are provided on all probe supports, the lines connecting the probes at the same radial position on each probe support form concentric circles, and the annular area divided by any two adjacent circles in the concentric circles is equal to the area surrounded by the smallest circle in the concentric circles.

[0012] The air intake test apparatus described above is further preferably further comprising: a distortion generation section disposed between the wind tunnel and the first measurement section; wherein a total pressure distortion generator and / or a vortex distortion generator are installed in the distortion generation section.

[0013] The air intake experimental apparatus described above is further preferably further comprising: a first transition section disposed between the wind tunnel and the distortion generation section, and a second transition section disposed between the air intake and the second measurement section; the first transition section is used to transition the outlet inner diameter of the wind tunnel to an inner diameter suitable for connection with the inlet of the distortion generation section; the second transition section is used to transition the outlet inner diameter of the air intake to an inner diameter suitable for connection with the inlet of the second measurement section.

[0014] The air intake test apparatus described above is further preferably further comprising: an adjustable bracket, the adjustable bracket being supported on the air intake and / or the second measuring section; the support height of the adjustable bracket is adjustable to accommodate the installation of multiple sets of air intakes with different geometries.

[0015] The air intake experimental device described above is further preferably configured such that the wind tunnel, the first transition section, the distortion generation section, the first measurement section, the air intake, the second transition section, and the second measurement section are connected by a quick-connect interface.

[0016] The air intake experimental apparatus described above is further preferably characterized in that the complex geometric configuration of the air intake includes one of an S-shaped air intake, a variable geometry air intake, and a DSI air intake.

[0017] Analysis shows that, compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0018] The air intake of this invention is a full-size or scaled-down model, enabling direct study and measurement of the distortion characteristics generated by air intakes with complex geometries. The second measurement section is used to measure the flow field distortion at the air intake outlet, measuring both total pressure distortion and swirling distortion, facilitating the study of distortion patterns caused by complex air intake geometries. Both the air intake and the second measurement section are modular and replaceable. By replacing different air intakes, the flow field characteristics under multiple air intakes with different geometries can be studied. The coupled flow field of total pressure and swirling distortion generated by complex air intake geometries can be directly measured and reconstructed, facilitating the study of the impact of the air intake's presence on the compressor and the overall engine's steady-state and dynamic characteristics during aero-engine testing and research. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the air intake experimental device of the present invention;

[0020] Figure 2 For the present invention Figure 1 The main view;

[0021] Figure 3 This is a schematic diagram of the structure of the second measuring section of the present invention;

[0022] Figure 4 For the present invention Figure 3 The main view;

[0023] Figure 5 This is a schematic diagram of the air intake duct of the present invention;

[0024] Figure 6 This is a schematic diagram of the structure of the second transition section of the present invention.

[0025] In the diagram: 1-Wind tunnel; 2-First transition section; 3-Distortion generation section; 4-First measurement section; 5-Inlet; 6-Second transition section; 7-Second measurement section; 8-Nozzle; 9-Adjustable bracket; 10-Probe bracket; 11-Probe; 12-Pressure sensor. Detailed Implementation

[0026] 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.

[0027] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0028] Please refer to Figures 1 to 6 , Figure 1 This is a schematic diagram of the structure of the air intake experimental device of the present invention; Figure 2 For the present invention Figure 1 The main view; Figure 3 This is a schematic diagram of the structure of the second measuring section of the present invention; Figure 4 For the present invention Figure 3 The main view; Figure 5 This is a schematic diagram of the air intake duct of the present invention; Figure 6 This is a schematic diagram of the structure of the second transition section of the present invention. Wherein, in Figure 1 and Figure 2 The simplified schematic diagram used in the distortion generation section and the first measurement section is shown in the image. Figure 4 In the image, the concentric circles drawn with dashed lines are for illustrative purposes, not to represent the actual structure.

[0029] like Figure 1 and Figure 2As shown, this invention provides an inlet experimental apparatus for measuring total pressure distortion and / or swirling distortion in an inlet. Along the flow path, the inlet experimental apparatus includes a wind tunnel 1, an inlet 5, a second measurement section 7, and a nozzle 8 or compressor test bench located after the second measurement section 7. The inlet 5 is a complex geometric inlet, and is a full-size or scaled-down model of the inlet, oriented towards the actual geometry of the inlet, allowing direct study of the distortion characteristics generated by the complex geometric inlet. The second measurement section 7 is used to measure the flow field distortion at the outlet of the inlet 5, and can measure both total pressure distortion and swirling distortion, facilitating the study of the distortion patterns caused by the complex geometric inlet.

[0030] In this invention, both the air inlet 5 and the second measurement section 7 are modular designs that can be disassembled and replaced. By replacing different air inlets 5, the flow field characteristics under multiple sets of air inlets with different geometries can be studied. The air inlet 5 is similar to the complex geometric configuration air inlets used in actual aircraft in terms of geometric dimensions (e.g., length of air inlet 5, cross-sectional expansion rate, axial offset, etc.), thereby simulating the distorted flow field caused downstream by the corresponding real complex geometric configuration air inlet under actual flight conditions. The total pressure and swirling distortion coupled flow field generated by the complex geometric configuration air inlet can be directly measured and reconstructed, which is convenient for studying the impact of the presence of the air inlet on the compressor and the steady-state and dynamic characteristics of the entire engine during the aero-engine testing and research phase.

[0031] like Figure 5 As shown, in one embodiment of the present invention, a plurality of pressure sensors 12 are distributed along the flow path on the intake duct 5 to measure the static pressure distribution of the flow field within the intake duct 5. The plurality of pressure sensors 12 are disposed on the upper and / or lower wall surfaces of the intake duct 5. Preferably, a plurality of pressure sensors 12 are simultaneously installed on both the upper and lower wall surfaces of the intake duct 5, enabling the measurement of the static pressure distribution along the flow path within the intake duct 5.

[0032] like Figure 2 As shown, in another embodiment of the present invention, a first measuring section 4 is provided between the wind tunnel 1 and the air intake 5, which can measure the flow field at the inlet position of the air intake 5.

[0033] like Figure 3As shown, in another embodiment of the present invention, both the first measuring section 4 and the second measuring section 7 include probes 11 and probe supports 10 that provide mounting positions for the probes 11. Multiple probe supports 10 are evenly distributed circumferentially along the corresponding first measuring section 4 or second measuring section 7. Specifically, one end of the probe support 10 is fixed to the inner wall of the corresponding first measuring section 4 or second measuring section 7, and the other end of the probe support 10 extends towards the center point of the corresponding first measuring section 4 or second measuring section 7. At least one probe 11 is provided on each probe support 10. When multiple probes 11 are provided on a probe support 10, each probe 11 is distributed along the direction from one end of the probe support 10 to the other end. Taking the first measuring section 4 as an example, the multiple probe supports 10 are arranged in a circumferential array on the inner wall of the first measuring section 4, enabling the measurement of the flow field at the inlet of the air intake 5. Similarly, the multiple probes 11 installed in the second measuring section 7 can measure the flow field at the outlet of the air intake 5.

[0034] like Figure 3 As shown, in another embodiment of the present invention, the probe holder 10 is shaped like an aero-engine compressor blade, which can avoid excessive interference to the flow field.

[0035] like Figure 3 and Figure 4 As shown, in another embodiment of the present invention, each probe holder 10 has a probe 11 installed at the same radial position, and the probe holder 10 and probe 11 have a one-to-many relationship. When all probe holders 10 are provided with multiple probes 11, the lines connecting the probes 11 at the same radial position on each probe holder 10 form concentric circles (multiple circles with the same center but different radii). The annular area divided by any two adjacent circles in the concentric circles is equal to the area surrounded by the smallest circle in the concentric circles, and the annular areas of any two divided circles are also equal. This embodiment arranges the probes 11 based on the circular cross-sectional area averaging measurement point arrangement method of the differential idea, which can use fewer probes 11 to more scientifically measure and evaluate the parameters on the cross-section. As one possible implementation, the number of probe holders 10 is eight, and the included angle between adjacent probe holders is 45°, which can comprehensively detect flow field data.

[0036] like Figure 1As shown, in another embodiment of the present invention, a distortion generation section 3 is provided between the wind tunnel 1 and the first measurement section 4, which can directly target real flight conditions. Specifically, a total pressure distortion generator and / or a vortex distortion generator are installed in the distortion generation section 3. The distortion generation section 3 creates distorted air intake at the inlet of the air intake 5, which can simulate the non-uniform airflow at the inlet of the air intake 5 and the non-uniform flow field characteristics downstream of the air intake 5 caused by the non-uniformity of the airflow at the inlet of the air intake 5 and the air intake 5 itself. In this way, it can simulate the non-uniform flow field at the inlet of the complex geometric configuration of the air intake caused by different flight attitudes or flight conditions during the actual flight of the aircraft, and directly simulate actual flight conditions such as boundary layer inhalation and complex angles of attack and sideslip angles. In this embodiment, the total pressure distortion generator is mainly used to simulate the total pressure deficit at a fixed position. It generally comes in different forms such as inserts, grids, and distortion meshes. Their common feature is that they are fixed obstacles that can generate total pressure deficit. Swirl distortion generators are mainly used to simulate inlet conditions with tangential swirling velocities in a local or entire cross section. In order to obtain rotating flow, swirl distortion generators can adopt delta airfoils, guide vanes, and inlet volutes, etc.

[0037] like Figure 2 As shown, in another embodiment of the present invention, a first transition section 2 is provided between the wind tunnel 1 and the distortion generation section 3; the inner diameter of the first transition section 2 is gradually changed, with the inner diameter at one end matching the inner diameter of the air outlet of the wind tunnel 1, and the inner diameter at the other end matching the inner diameter of the inlet of the distortion generation section 3, so that the outlet inner diameter of the wind tunnel 1 can be transitioned to an inner diameter suitable for connecting with the inlet of the distortion generation section 3, which facilitates the connection between the wind tunnel 1 and the distortion generation section 3.

[0038] like Figure 1 and Figure 6 As shown, in another embodiment of the present invention, a second transition section 6 is installed between the air intake duct 5 and the second measuring section 7. The inner diameter of the second transition section 6 is gradually changed, with the inner diameter at one end matching the outlet inner diameter of the air intake duct 5 and the inner diameter at the other end matching the inlet inner diameter of the second measuring section 7. This allows the outlet inner diameter of the air intake duct 5 to transition to an inner diameter suitable for connection with the inlet of the second measuring section 7, facilitating the connection between the air intake duct 5 and the second measuring section 7.

[0039] like Figure 1 and Figure 2 As shown, in another embodiment of the present invention, an adjustable bracket 9 is also included, which is supported on the air intake duct 5 and / or the second measuring section 7. The support height of the adjustable bracket 9 is adjustable, which can accommodate the installation of multiple sets of air intake ducts 5 with different geometries, and adapt to the experimental environment.

[0040] like Figure 1 and Figure 6As shown, in another embodiment of the present invention, for ease of connection, the wind tunnel 1, the first transition section 2, the distortion generation section 3, the first measurement section 4, the air intake 5, the second transition section 6, and the second measurement section 7 are connected via quick-connect interfaces. Specifically, the quick-connect interface includes mounting edges and positioning rings. The main bodies of the first transition section 2, the distortion generation section 3, the first measurement section 4, the air intake 5, the second transition section 6, and the second measurement section 7 are all tubular, with mounting edges located at both ends of the tubular main body, and positioning rings disposed on the mounting edges. During connection, the positioning rings serve a positioning function, and adjacent mounting edges are connected (for example, by bolts and nuts), facilitating assembly and disassembly and ensuring accurate positioning. The first transition section 2, the distortion generation section 3, the first measurement section 4, the air intake 5, the second transition section 6, and the second measurement section 7 are all modularly designed, relatively small, saving costs, and can be flexibly installed according to experimental purposes.

[0041] like Figure 1 and Figure 5 As shown, in the present invention, the complex geometric configuration of the intake duct 5 during experiments includes, but is not limited to, an S-shaped intake duct, a variable geometry intake duct, and a DSI intake duct (DSI is an abbreviation for Diverterless Supersonic Inlet). The second measurement section 7 can be connected to the nozzle 8, which is a variable diameter circular pipe with a slowly expanding diameter, allowing for independent experiments on the intake duct. The second measurement section 7 can also be connected to a compressor test bench, enabling experimental research using the intake distortion flow field as the inlet boundary condition of the compressor test bench. This allows for examination of the impact of the intake duct's presence on the steady-state and dynamic characteristics of the compressor and the entire engine under different intake duct inlet conditions, directly exploring the stability characteristics of the overall system consisting of the intake duct and the engine.

[0042] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. An intake duct experimental apparatus for testing total pressure distortion and swirl distortion of an intake duct, characterized in that, Along the flow path, the air intake test device includes a wind tunnel, an air intake, a second measurement section for measuring the flow field distortion at the outlet of the air intake, and a nozzle or compressor test bench located after the second measurement section. The air intake is a complex geometric configuration, and the air intake is a full-size model or a scaled-down model. The air intake is also equipped with multiple pressure sensors distributed along the flow direction of the flow field. The pressure sensors are used to measure the static pressure distribution of the flow field inside the air intake. Multiple pressure sensors are disposed on the upper and / or lower wall surfaces of the air intake duct; A first measurement section is provided between the wind tunnel and the air intake, and the first measurement section is used to measure the flow field at the inlet position of the air intake; Both the first measurement segment and the second measurement segment include a probe and a probe holder for mounting the probe; Multiple probe supports are evenly distributed circumferentially along the corresponding first or second measurement segment. One end of each probe support is fixed to the inner wall of the corresponding first or second measurement segment, and the other end of each probe support extends toward the center point of the corresponding first or second measurement segment. At least one probe is provided on each probe holder. When multiple probes are provided on a probe holder, each probe is distributed along the direction from one end of the probe holder to the other end. It also includes a distortion generation section located between the wind tunnel and the first measurement section; The distortion generation section is equipped with a total pressure distortion generator and a vortex distortion generator; The probe holder is shaped like an aero-engine compressor blade. The probe is mounted at the same radial position on each of the probe holders; When all the probe holders are provided with multiple probes, the lines connecting the probes at the same radial position on each probe holder form concentric circles, and the annular area divided by any two adjacent circles in the concentric circles is equal to the area surrounded by the smallest circle in the concentric circles. Both the air intake and the second measurement section are modular and can be disassembled and replaced. By replacing different air intakes, it is possible to study the flow field characteristics under multiple air intakes with different geometries and directly measure and reconstruct the coupled flow field of total pressure and swirling distortion generated by the complex geometric configuration of the air intake. The distortion generation section creates distorted air intake at the inlet of the air intake, which can simulate the non-uniform airflow at the inlet of the air intake and the non-uniform flow field characteristics downstream of the air intake caused by the non-uniform airflow at the inlet of the air intake itself. In turn, it can simulate the non-uniform flow field at the inlet of the complex geometric configuration of the air intake caused by different flight attitudes or flight conditions during the actual flight of the aircraft.

2. The intake duct experimental apparatus according to claim 1, characterized in that: It also includes a first transition section between the wind tunnel and the distortion generation section, and a second transition section between the air intake and the second measurement section; The first transition section is used to transition the outlet inner diameter of the wind tunnel to an inner diameter suitable for connection with the inlet of the distortion generation section; The second transition section is used to transition the outlet inner diameter of the air intake to an inner diameter suitable for connection with the inlet of the second measuring section.

3. The intake duct experimental apparatus according to claim 1, characterized in that: It also includes an adjustable bracket, which is supported on the air intake and / or the second measuring section; The adjustable bracket has an adjustable support height to accommodate the installation of multiple intake ducts with different geometries.

4. The intake duct experimental apparatus according to claim 2, characterized in that: The wind tunnel, the first transition section, the distortion generation section, the first measurement section, the air intake, the second transition section, and the second measurement section are connected by quick-connect interfaces.

5. The intake duct experimental apparatus according to claim 1, characterized in that: The complex geometry of the air intake includes one of the following: S-type air intake, variable geometry air intake, and DSI air intake.

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