Aircraft wingtip vortex measurement method and measurement device

Abstract

The application discloses an aircraft wingtip vortex measuring method and a measuring device, and aims to solve the problem that current wingtip vortex characteristic analysis mainly adopts numerical simulation and wind tunnel test methods, numerical simulation has extremely high requirements on pre-processing scale and computing resources, and full-range simulation cannot be achieved usually, wind tunnel test has extremely high cost, and test results are indirect quantities of the influence of a long machine on a wingman, wingtip vortex characteristics of the long machine cannot be analyzed, and the generality of the long machine for different flight speeds or different aircraft configurations is low. The measuring device comprises a test rake unit, a displacement unit and a connecting support plate, the displacement unit is connected with the connecting support plate, and the test rake unit is connected with the displacement unit. The application can realize accurate and rapid testing of the wingtip vortex of the long machine through a brand-new testing device and a testing method, improves the testing efficiency and accuracy of the wingtip vortex of the aircraft, and provides a powerful means for wingtip vortex influence evaluation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of experimental aerodynamics, and proposes a method and a device for measuring aircraft wingtip vortex. BACKGROUND

[0002] The wingtip vortex refers to the vortex flow generated at the wingtip of an aircraft, and is the main part of the wake flow formed during flight. The wingtip vortex is caused by the existence of air flow rolling from the lower wing surface to the upper wing surface at the wingtip, forming a vortex-shaped air flow extending backward and downward at high speed with the wingtip as the center. The two vortexes formed at the two wingtips of the wing have opposite directions, and the vortexes form obvious downwash air flow inside and upwash air flow outside, which affects the aircraft passing behind. The strength of the wingtip vortex is determined by the weight of the aircraft, the flight speed and the wing shape. The influence of the wingtip vortex is particularly obvious in the multi-aircraft formation flight or the repeated take-off and landing area above the airport runway. The aircraft located in the influence area of the wingtip vortex of the aircraft will be obviously disturbed, resulting in rolling and swinging, and even causing asymmetric separation in severe cases, which not only reduces the control quality, but also may cause the engine to stop. Therefore, predicting the generation and development of the wingtip vortex, determining the vortex center position and the sinking law, has a crucial role in improving flight quality and flight safety and ensuring the stability of the formation.

[0003] At present, the analysis of the characteristics of the wingtip vortex mainly adopts numerical simulation and wind tunnel test methods. Since the vortex generation is closely related to the aircraft boundary layer transition and separation characteristics, fine modeling of the wide area downstream of the aircraft is required in numerical simulation to accurately capture the development and evolution characteristics of the vortex, which has extremely high requirements for pre-processing scale and computing resources, and full-range simulation is usually impossible. The currently available wind tunnel test method is mainly multi-body interference simulation technology, that is, the position and attitude of the long aircraft (the front aircraft) are fixed, the relative position and attitude of the wingman (the rear aircraft) to the long aircraft are changed, and the influence of the long aircraft wake vortex on the aerodynamic characteristics of the wingman is obtained. This method has extremely high cost, and the test results are indirect quantities of the influence of the long aircraft on the wingman, and cannot analyze the characteristics of the wingtip vortex of the long aircraft. The universality of this method is low for different flight speeds or different aircraft configurations.

[0004] Considering the generation, development, and dissipation of wingtip vortices in aircraft, and the relative distance between the lead and wingmen in a formation, the rotational speed of the vortex region where the wingman is located is usually relatively stable, and the influence of the wingman on the lead aircraft is negligible. Therefore, under the condition of a single lead aircraft model, while maintaining constant operating speed and model attitude, a dedicated testing device and method can be developed to test the characteristics of wingtip vortices. Leveraging the advantages of a controllable simulation environment and high accuracy of experimental data, this approach compensates for the shortcomings of existing numerical simulation methods and wind tunnel testing methods, providing a foundation for the analysis of the impact of wingtip vortices on aircraft and for formation flight safety control. Summary of the Invention

[0005] The purpose of this invention is to address the current limitations of wingtip vortex characteristic analysis, which primarily relies on numerical simulation and wind tunnel testing. Numerical simulation demands extremely high levels of preprocessing and computational resources, often failing to achieve full-range simulation. Wind tunnel testing, on the other hand, is extremely costly, and its results only provide indirect data on the lead aircraft's influence on wingmen, lacking the ability to analyze the lead aircraft's wingtip vortex characteristics. Furthermore, it suffers from low versatility across different flight speeds and aircraft configurations. This invention provides a method and apparatus for measuring aircraft wingtip vortexes. Through a novel testing device and method, this invention enables accurate and rapid testing of lead aircraft wingtip vortices, improving the efficiency and accuracy of wingtip vortex testing and providing a powerful tool for assessing the impact of wingtip vortices.

[0006] A method for measuring wingtip vortices in an aircraft includes the following steps:

[0007] (1) The center of the test section entrance is the origin of the coordinate axis; the X-axis is the longitudinal body axis, along the direction of the test section axis, with the reverse airflow being positive; the Y-axis is in the vertical plane and perpendicular to the X-axis, with upward being positive; the Z-axis is perpendicular to the X-axis and Y-axis, and is determined by the right-hand rule;

[0008] (2) Set up the test model on the side wall at the entrance of the test section and adjust the test model according to the set requirements;

[0009] (3) Pass the test probe through the probe mounting hole on the rake body and set it on the rake body to ensure that the test probe is firmly installed on the rake body. Use the probe positioning hole on the top of the rake body to ensure that the relative position between the test probe and the rake body is fixed, thereby forming a test rake unit.

[0010] (4) Install the stepper motor, sliding component and limit block in the displacement unit on the support component respectively, and fix the support component to the connecting support plate; then, pass the lead screw lever through the lever nut connected to the translation table, and connect the lead screw lever to the output shaft of the stepper motor;

[0011] (5) Fix the test rake unit on the translation platform to complete the assembly of the aircraft wingtip eddy current measurement device;

[0012] (6) connecting the aircraft wingtip vortex measuring device with the wind tunnel test section support;

[0013] (7) adjusting the longitudinal position of the probe head of the test probe to reach the set position;

[0014] (8) starting the wind tunnel;

[0015] (9) after the flow field is stable, moving the normal position of the test rake unit to the set position by using the wind tunnel test section support, collecting the probe data at the current position to obtain the local airflow direction data; moving the lateral position of the test rake unit to the set position by using the translation table, collecting the probe data at the current position to obtain the local airflow direction data;

[0016] (10) completing the airflow direction test at different positions according to the defined spacing and test range;

[0017] (11) completing the measurement at all test positions and stopping the operation of the wind tunnel;

[0018] (12) drawing streamlines according to the moving test grid points and reconstructing the pre-vehicle tail vortex flow field.

[0019] The wind tunnel test section support is a middle support of the wind tunnel test section.

[0020] An aircraft wingtip vortex measuring device comprises a test rake unit, a displacement unit, a connecting support plate for connecting with a wind tunnel test section support, the displacement unit is connected with the connecting support plate and the connecting support plate can provide support for the displacement unit, and the test rake unit is connected with the displacement unit and the displacement unit can drive the test rake unit to move.

[0021] The test rake unit comprises a rake body, a test probe and a probe positioning member, the rake body comprises a windward front end and a middle connecting end, the windward front end of the rake body is in the shape of a sharp wedge, the middle connecting end of the rake body is in the shape of a rectangular body structure, and the windward front end and the middle connecting end are connected in sequence and integrated.

[0022] The middle connecting end is provided with probe mounting holes for mounting the test probe and probe positioning holes matched with the probe positioning member, the probe mounting holes and the probe positioning holes are respectively N in number, N is a natural number and N≥2, and the probe mounting holes are arranged in parallel with each other;

[0023] In the direction from the windward front end to the middle connecting end, the probe mounting holes pass through the windward front end and the middle connecting end in sequence, the test probe is arranged on the rake body through the probe mounting holes; the probe positioning holes are arranged on the middle connecting end, the probe positioning holes are communicated with the probe mounting holes, the probe positioning member is matched with the probe mounting holes and can adjust the position of the test probe and fix the test probe in the probe mounting holes through the cooperation of the probe positioning member and the probe mounting holes;

[0024] The displacement unit comprises a flow guide wedge, a support assembly, a stepping motor, a screw rod assembly, a sliding assembly and a translation table, the flow guide wedge is in the shape of a half-angle wedge with a flat upper end and a pointed lower end, and the support assembly is fixedly connected with the flow guide wedge;

[0025] The support assembly comprises a bottom fixing seat, a motor fixing seat and a screw rod fixing seat, the bottom fixing seat is in the shape of a flat plate, the bottom fixing seat is connected with the flow guide wedge as a whole, and the bottom fixing seat is located on the side of the flow guide wedge opposite to the air flow direction; the motor fixing seat and the screw rod fixing seat are respectively arranged on the bottom fixing seat, and the bottom fixing seat can provide support for the motor fixing seat and the screw rod fixing seat respectively;

[0026] The upper end plane of the flow guide wedge is in sliding surface contact with the bottom plane of the rake body, and the flow guide wedge can provide support for the test rake unit through the cooperation of the upper end plane and the bottom plane of the rake body;

[0027] The screw rod assembly comprises a screw rod lever and a lever nut matched with the screw rod lever; the stepping motor is arranged on the motor fixing seat, the stepping motor is located on the side of the flow guide wedge opposite to the air flow direction, the screw rod lever is connected with the screw rod fixing seat, and the screw rod lever can rotate relative to the screw rod fixing seat;

[0028] The output shaft of the stepping motor is connected with the screw rod lever, the lever nut is arranged on the screw rod lever, the translation table is connected with the lever nut, and the stepping motor can drive the translation table to move along the axial direction of the screw rod lever;

[0029] The sliding assembly comprises a sliding guide rail and a sliding block arranged on the sliding guide rail, the sliding guide rail is arranged on the bottom fixing seat, and the bottom fixing seat can provide support for the sliding guide rail, and the sliding block is arranged on the sliding guide rail and can slide along the axial direction of the sliding guide rail relative to the sliding guide rail;

[0030] The translation table is connected with the sliding block, and the sliding assembly can guide the translation table, the rake body is connected with the translation table, and the translation table can drive the test rake unit to move synchronously;

[0031] The windward surface of the connecting support plate is the front edge of the wedge, one end of the connecting support plate is fixedly connected with the displacement unit, and the other end of the connecting support plate can be connected with the middle support of the test section of the wind tunnel.

[0032] The rake body has an acute angle at the windward front end, and the acute angle at the windward front end of the rake body is less than 20°.

[0033] The rake body further comprises a tail connecting end for being connected with the displacement unit, and the windward front end, the middle connecting end and the tail connecting end are connected in sequence as a whole.

[0034] The connecting support plate is fixedly connected with the support of the test section of the wind tunnel.

[0035] The screw rod fixing seat is located at the reverse airflow side of the flow guide wedge.

[0036] The test rake unit further comprises a fixing connector, and a fixing mounting hole for connecting the rake body with the displacement unit is further arranged on the middle connecting end;

[0037] The fixing connector can pass through the fixing mounting hole, and the rake body is connected with the translation table through the fixing connector and the translation table can drive the test rake unit to move synchronously.

[0038] The probe positioning member and the fixing connector are one or more of bolts and screw rods.

[0039] The displacement unit further comprises a limiting block, the limiting block is arranged on the bottom fixing seat and the bottom fixing seat can provide support for the limiting block, the limiting block is a group, and the limiting blocks are located on both sides of the translation table and can be used for zero position confirmation of the translation table and safety protection during operation.

[0040] The connecting support plate and the displacement unit are connected by bolts or welding.

[0041] The upper end surface of the connecting support plate is a mounting plane for connecting with the displacement unit, and the connecting support plate is respectively provided with a pipeline fastening hole for connecting with a test probe pipeline, a positioning pin hole for cooperating with a positioning pin, and a fastening bolt hole for cooperating with a connecting bolt to realize connection between the connecting support plate and a wind tunnel test section support.

[0042] The connecting support plate and the wind tunnel test section support are connected by bolts or pins.

[0043] As described above, the current wind tunnel multi-body test result is mainly wing tip vortex interference quantity, which is indirect measurement and cannot directly obtain the direction, speed, position and other information of the long machine wing tip vortex. Therefore, the application provides an aircraft wing tip vortex measurement method and device, which is a fast and reliable test scheme, obtains the airflow direction, speed and other information of the long machine wing tip vortex area based on a directional probe, and can directly analyze the wing tip vortex characteristics.

[0044] The wedge shape is a wedge shape, which is symmetrical up and down, generally an acute angle of 15-30°, and is used for flow regulation and reduction of blockage disturbance. In the application, the upper surface of the flow guide wedge is to be installed with a rake body, so it is only a half wedge shape, and the upper surface is horizontal, so the flow guide wedge of the application is a half-angle wedge shape with a flat upper surface and a sharp lower surface.

[0045] Meanwhile, the multi-point displacement method can quickly change the lateral and vertical positions of the test device, realize the flow field test of any grid density, and does not need to manually change the test position after the wind tunnel is closed, so that the wing tip vortex test efficiency and accuracy can be greatly improved.

[0046] Finally, the wing tip vortex test is carried out in combination with the direction probe, according to the probe clamping type, the test harrow can be replaced and only needs to be reinstalled on the support bottom plate, the test instrument has high universality and high use value, and has important significance for reducing the wing tip vortex test cost and ensuring flight safety. DETAILED DESCRIPTION

[0047] The application will be described by way of example and with reference to the accompanying drawings, in which:

[0048] Figure 1 The structure diagram of the test device for measuring the wing tip vortex of the aircraft in embodiment 1.

[0049] Figure 2 The structure diagram of the displacement unit in the measuring device in embodiment 1.

[0050] Figure 3 The structure diagram of the test harrow unit in embodiment 1.

[0051] Figure 4 The structure diagram of the connecting support plate in embodiment 1.

[0052] Figure 5 The grid diagram obtained by synthesizing the Y and Z direction air flow velocity components in embodiment 1.

[0053] Marked in the figure: 1, guide vane, 2, stepping motor, 3, screw assembly, 4, translation stage, 5, sliding assembly, 6, limit block, 7, harrow body, 8, test harrow unit, 9, probe positioning hole, 10, fixed mounting hole, 11, probe mounting hole, 12, mounting plane, 13, pipeline fastening hole, 14, vane leading edge, 15, fastening bolt hole, 16, positioning pin hole. DETAILED DESCRIPTION

[0054] All features disclosed in this specification, and / or the steps of any method or process specified in this specification, can be combined in any combination, except combinations where at least some features and / or steps are mutually exclusive.

[0055] Any of the features disclosed in this specification, unless explicitly stated otherwise, can be replaced by alternative features serving the same, equivalent or similar purpose.

[0056] Embodiment 1

[0057] (I) Test device

[0058] In this embodiment, the aircraft wingtip vortex measuring device mainly consists of a test rake unit, a displacement unit, and a connecting support plate for connecting with the support of the test section of the wind tunnel. The displacement unit is erected on the connecting support plate, and the connecting support plate can provide support for the displacement unit. The test rake unit is arranged on the displacement unit. In this embodiment, the connecting support plate is fixedly connected with the middle support of the test section of the wind tunnel.

[0059] The test rake unit comprises a rake body, a test probe, a probe positioning member, and a fixed connecting member. The rake body comprises a windward front end and a middle connecting end. The windward front end of the rake body is in the shape of a sharp wedge, and the middle connecting end of the rake body is in the shape of a rectangular body. The windward front end and the middle connecting end are connected in sequence and integrated as a whole. In the direction from the windward front end to the middle connecting end, the probe mounting holes pass through the windward front end and the middle connecting end in sequence. The middle connecting end is provided with probe mounting holes for arranging test probes, probe positioning holes matched with the probe positioning member, and fixed mounting holes for connecting the rake body with the displacement unit. The probe mounting holes and the probe positioning holes are N in number, N is a natural number and N≥2, and the probe mounting holes are arranged in parallel with each other. The probe positioning holes are arranged on the middle connecting end and are in communication with the probe mounting holes. The probe positioning member is matched with the probe mounting holes and can fix the test probe in the probe mounting hole through the cooperation of the probe positioning member and the probe mounting hole. Preferably, the rake body further comprises a tail connecting end for connecting with the displacement unit, and the windward front end, the middle connecting end, and the tail connecting end are connected in sequence and integrated as a whole. In this embodiment, the windward front end of the rake body is an acute angle, and the windward front end of the rake body is <20°. The test probe is arranged on the rake body, and the clamping and positioning mode of the test probe is designed according to the form of the test probe.

[0060] The displacement unit comprises a flow guide wedge, a support assembly, a stepping motor, a lead screw assembly, a sliding assembly, and a translation stage. The flow guide wedge is in the shape of a half-angle wedge with a flat upper end and a sharp lower end. The support assembly is fixedly connected with the flow guide wedge. The sliding assembly is connected with the support assembly, and the support assembly can provide support for the sliding assembly. The support assembly is located on the reverse airflow side of the flow guide wedge. The upper end plane of the flow guide wedge is in sliding surface contact with the bottom plane of the rake body, and the flow guide wedge can provide support for the test rake unit through the cooperation of the upper end plane of the flow guide wedge and the bottom plane of the rake body. The support assembly comprises a bottom fixed seat, a motor fixed seat, and a lead screw fixed seat. The bottom fixed seat is in the shape of a flat plate, and the bottom fixed seat is connected with the flow guide wedge as a whole.

[0061] The screw rod assembly comprises a screw rod lever and a lever nut matched with the screw rod lever. The output shaft of the stepper motor is connected with the screw rod lever, the lever nut is arranged on the screw rod lever, the translation table is connected with the lever nut, and the stepper motor can drive the translation table to move along the axial direction of the screw rod lever through the cooperation of the screw rod lever and the lever nut. The sliding assembly comprises a sliding guide rail and a sliding block arranged on the sliding guide rail. The sliding guide rail is arranged on the support assembly, and the support assembly can provide support for the sliding guide rail; the sliding block is arranged on the sliding guide rail, and the sliding block can slide relative to the sliding guide rail along the axial direction of the sliding guide rail. The translation table is connected with the sliding block, and the sliding assembly can guide the translation table. In the embodiment, the stroke of the translation table can be determined according to the distance between the test probes arranged on the test rake unit. In theory, the moving range is more than 1 times the distance between the test probes, and the flow field measurement at any density grid point can be realized. The fixed connecting piece can pass through the fixed mounting hole, the rake body is connected with the translation table through the fixed connecting piece, and the translation table can drive the test rake unit to move synchronously. In this way, the translation table can be used to install the rake body, the upper plane of the flow guide wedge can provide support for the rake body, and the lower wedge shape of the flow guide wedge can reduce the influence of the displacement unit on the flow field as a whole. The stepper motor is installed on the side of the displacement unit opposite to the air flow direction and located behind the flow guide wedge. Through the sliding assembly, the translation direction of the translation table can be ensured, and the mechanism can be prevented from being stuck after deformation under load.

[0062] In one example, the upper surface of the translation table is used to install the test rake unit, and the translation table is connected with the lever nut. In this structure, when the output shaft of the stepper motor drives the screw rod lever to rotate, the translation table can be driven to move accurately along the axial direction of the screw rod lever. The bottom of the translation table is fixedly connected with the sliding block, and the sliding block can play a supporting and guiding role when the translation table moves. The screw rod lever passes through the middle part of the translation table, and the translation of the translation table is realized through the stepper motor. In the embodiment, the probe positioning member and the fixed connecting piece are one or more of bolts and screws. Further, the displacement unit further comprises a limiting block arranged on the support assembly. The limiting block is used for zero position confirmation of the translation table and safety protection during operation, eliminates the accumulated error of the system during reciprocating operation, and can prevent the translation table from being displaced incorrectly in case of incorrect operation.

[0063] The motor fixing seat, the screw rod fixing seat, the sliding guide rail and the limiting block are arranged on the bottom fixing seat, and the bottom fixing seat can provide support for the motor fixing seat, the screw rod fixing seat, the sliding guide rail and the limiting block. The stepper motor is arranged on the motor fixing seat, and the motor fixing seat can provide support for the stepper motor. The screw rod lever is connected with the screw rod fixing seat and can rotate relative to the screw rod fixing seat. In one specific example, the screw rod fixing seat is located on the right side of the mechanism (opposite to the air flow direction) and is used to provide support for the screw rod lever.

[0064] One end of the connecting support plate is fixedly connected with the displacement unit, and the other end of the connecting support plate is adapted to the middle support of the wind tunnel test section. The whole aircraft wing tip vortex measuring device is installed on the middle support of the wind tunnel; wherein the connecting support plate and the displacement unit are connected by bolts, or are connected by welding; the connecting support plate and the middle support of the wind tunnel test section are mainly connected by bolts and pins.

[0065] In one specific example, the upper end surface of the connecting support plate is an installation plane for connecting with the displacement unit, and the windward surface of the connecting support plate is a sharp wedge front edge. The connecting support plate is respectively provided with a pipeline fastening hole for connecting with a test probe pipeline, a positioning pin hole for cooperating with a positioning pin, and a fastening bolt hole for cooperating with a connecting bolt to realize the fixed connection between the connecting support plate and the middle support of the wind tunnel test section.

[0066] Further, the embodiment provides a preparation process of the foregoing device.

[0067] Firstly, according to the form of the directional probe (i.e. the form of the test probe) used, the rake body is processed, and the main parameters include the number of directional probes (i.e. the number of test probes), the clamping position / form, the probe positioning hole, the pipeline laying, the attitude check and the like.

[0068] Secondly, the rake body is installed on the flow guide sharp wedge and the translation table. The bottom plane of the rake body is in sliding surface contact with the upper part of the flow guide sharp wedge, and the middle connection end of the rake body is fastened with the translation table by means of bolts.

[0069] Thirdly, the support assembly of the displacement unit is fixedly connected with the connecting support plate, and a stepping motor, a limiting block, a lead screw assembly and a sliding assembly are respectively installed on the support assembly. The lead screw lever passes through the lever nut connected with the translation table.

[0070] Fourthly, the flow guide sharp wedge is fastened with the support assembly by means of bolts. The output shaft of the stepping motor is connected with the lead screw lever, and drives the lever nut and the translation table to translate along the sliding assembly. During installation, it is ensured that the components are connected tightly and there is no jamming during operation.

[0071] Fifthly, the probe pipeline connected with the test probe and the cable connected with the stepping motor are led out from the rear of the test rake unit, introduced into the middle support of the wind tunnel test section through the pipeline fastening holes on the back of the connecting support plate, and the whole installation of the displacement unit in the middle support of the wind tunnel test section is completed.

[0072] In the embodiment, the directional probe (i.e. the test probe) refers to a test instrument with a spherical or conical head and 5 or 7 pressure measuring holes, which can measure the flow field pressure, velocity and direction in combination with the calibration certificate.

[0073] The middle support in the test section of the wind tunnel is a curved knife type mechanism used for supporting the test model and testing instrument in the test section of the wind tunnel, and has the ability to change the posture and position according to different types of wind tunnels.

[0074] The flow guide wedge is a flow guide device at the front end of the test device, and the function is to reduce the influence of the non-streamlined devices such as the translation table and the stepping motor on the flow in front.

[0075] In order to achieve better technical effects, the application installs limiting blocks on the left and right sides of the translation table to avoid the accumulation of gap errors in the reciprocating operation of the translation table, and to improve the accuracy of positioning.

[0076] In order to achieve better technical effects, the application uses multiple direction probes (i.e. test probes) for testing to reduce the spacing between the direction probes (i.e. test probes) and improve the testing efficiency.

[0077] (2) The wing tip vortex is measured by using the measuring device of the embodiment.

[0078] In a cross supersonic wind tunnel with a test section size of 0.6m x 0.6m, the wing tip vortex of a certain layout long wing is tested. The long aircraft (i.e. test model) is installed in front of the test section, the test Mach number is 0.85, and the model angle of attack is 3°; the origin of the coordinate axis is located at the center of the test section entrance, the X axis is the longitudinal direction, along the test section axis direction, the reverse airflow is positive, the Y axis is the normal direction, along the test section vertical plane normal direction, upward is positive, and the Z axis is determined by the right hand rule. During the test, the position and posture of the long aircraft (i.e. test model) do not change.

[0079] The half-span length of the wing of the test model is 0.39m, the wing aspect ratio is 9.58, and the wing reference area is 0.063527m2.

[0080] The measuring device used for the test is installed on the middle support downstream of the test section of the wind tunnel, and 11 ball head five hole direction probes are used on the measuring device, which are clamped through the upper and lower cut cylindrical sections. The structure diagram of the measuring device used for the test is shown in Figure 1 .

[0081] The measurement process includes the following steps.

[0082] 1. Use the model installed on the test section entrance side wall to adjust the model angle to 3°.

[0083] 2. Install 11 test probes on the harrow body in turn, insert the test probes into the front of the harrow body through the probe installation holes, ensure that the clamping surfaces are firmly installed on the harrow body, and use the probe positioning holes above the harrow body to ensure the fixed relative position between the test probes and the harrow body, thereby forming a test harrow unit.

[0084] 3, The stepping motor, sliding assembly and limit block in the displacement unit are respectively installed on the support assembly, the support assembly is fixedly connected with the connecting support plate, then the lead screw lever passes through the lever nut connected with the translation table, and the lead screw lever is connected with the output shaft of the stepping motor.

[0085] 4, The test rake unit is installed on the translation table through the fixed mounting hole.

[0086] 5, Based on the positioning pin hole and fastening bolt hole on the connecting support plate, the aircraft wing tip vortex measurement device of the embodiment is connected to the middle support of the test section of the wind tunnel.

[0087] 6, The longitudinal position of the probe head of the test probe is adjusted to be 1 times the span length downstream of the model wing tip, that is, 0.78 meters.

[0088] 7, Start the wind tunnel. After the flow field is stabilized, the normal position of the test rake unit is moved to Y = -0.25 meters by using the middle support of the test section of the wind tunnel; the probe data at the current position is collected to obtain the local airflow direction data. The lateral position of the test rake unit is moved by 0.01 meters by using the translation table; the probe data at the current position is collected to obtain the local airflow direction data.

[0089] 8, According to the defined interval and test range, the airflow direction test at different positions is completed.

[0090] 9, All test positions are measured, and the wind tunnel operation is stopped.

[0091] 10, According to the moving grid points, the streamlines are drawn, and the pre- tail vortex flow field is reconstructed.

[0092] In this example, the normal movement of the test rake unit is realized by using the middle support of the test section of the wind tunnel, the range is Y = -0.25 ~ 0.25 meters, △Y = 0.025 m; the lateral movement of the test rake unit is realized by using the translation table, the range is Z = -0.1 ~ 0.11 meters, and the total number of measurement points is 462.

[0093] After obtaining the airflow velocity components of each point on the test grid, drawing is performed. The Y and Z direction airflow velocity components are synthesized and drawn on the grid chart in the form of a vector diagram, and the obtained results are as shown in Figure 5 .

[0094] It can be seen that the tail vortex flow spectrum diagram of the test model downstream of the test section inlet 0.78 meters is obtained according to the above test method, and it can be seen that there is obvious vortex flow downstream of the wing tip of the wing, and the vortex core is located at Y = 0.025 meters, Z = 0 meters.

[0095] The method of the present application can quickly obtain the key information such as the intensity of the wingtip vortex of the downstream area of the front aircraft (i.e. the long aircraft) and the vortex core position on the basis of reliability and firmness, and can provide a powerful means for improving the test efficiency and precision of the wingtip vortex.

[0096] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application do not deviate from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. An aircraft wing tip vortex measuring device, characterised in that, The test rake unit, the displacement unit, the connecting support plate for connecting with the support of the test section of the wind tunnel, the displacement unit is connected with the connecting support plate and the connecting support plate can provide support for the displacement unit, the test rake unit is connected with the displacement unit and the displacement unit can drive the test rake unit to move; The test rake unit includes a rake body, a test probe, and a probe positioning member, the rake body includes a windward front end and a middle connecting end, the windward front end of the rake body is in the shape of a wedge, the middle connecting end of the rake body is in the shape of a rectangular body, and the windward front end and the middle connecting end are sequentially connected as a whole; The middle connecting end is provided with probe mounting holes for arranging the test probes and probe positioning holes matched with the probe positioning member, the probe mounting holes and the probe positioning holes are respectively N, N is a natural number and N is greater than or equal to 2, and the probe mounting holes are arranged in parallel with each other; In the direction from the windward front end to the middle connecting end, the probe mounting holes sequentially penetrate the windward front end and the middle connecting end, the test probes are arranged on the rake body through the probe mounting holes, the probe positioning holes are arranged on the middle connecting end, the probe positioning holes are communicated with the probe mounting holes, the probe positioning member is matched with the probe mounting holes, and the position of the test probe can be adjusted and the test probe is fixed in the probe mounting hole through the cooperation of the probe positioning member and the probe mounting hole; The displacement unit includes a guide wedge, a support assembly, a stepping motor, a lead screw assembly, a sliding assembly, and a translation stage, the guide wedge is in the shape of a half-angle wedge with a flat upper end and a pointed lower end, and the support assembly is fixedly connected with the guide wedge; The support assembly includes a bottom fixing seat, a motor fixing seat, and a lead screw fixing seat, the bottom fixing seat is in the shape of a flat plate, the bottom fixing seat is connected with the guide wedge as a whole, and the bottom fixing seat is located on the side of the guide wedge opposite to the air flow direction; the motor fixing seat and the lead screw fixing seat are respectively arranged on the bottom fixing seat, and the bottom fixing seat can provide support for the motor fixing seat and the lead screw fixing seat respectively; The upper end plane of the guide wedge is in sliding surface contact with the bottom plane of the rake body, and the guide wedge can provide support for the test rake unit through the cooperation of the upper end plane and the bottom plane of the rake body; The lead screw assembly includes a lead screw lever and a lever nut matched with the lead screw lever, the stepping motor is arranged on the motor fixing seat, the stepping motor is located on the side of the guide wedge opposite to the air flow direction, the lead screw lever is connected with the lead screw fixing seat, and the lead screw lever can rotate relative to the lead screw fixing seat; The output shaft of the stepping motor is connected with the lead screw lever, the lever nut is arranged on the lead screw lever, the translation stage is connected with the lever nut, and the stepping motor can drive the translation stage to move along the axial direction of the lead screw lever; The sliding assembly includes a sliding guide rail and a sliding block arranged on the sliding guide rail, the sliding guide rail is arranged on the bottom fixing seat, and the bottom fixing seat can provide support for the sliding guide rail, the sliding block is arranged on the sliding guide rail, and the sliding block can slide along the axial direction of the sliding guide rail relative to the sliding guide rail; The translation stage is connected with the sliding block, the sliding assembly can guide the translation stage, the rake body is connected with the translation stage, and the translation stage can drive the test rake unit to move synchronously. The windward face of the connecting support plate is a wedge front edge; one end of the connecting support plate is fixedly connected with the displacement unit, and the other end of the connecting support plate can be connected with the middle support of the wind tunnel test section.

2. The measuring device of claim 1, wherein, The included angle of the windward front end of the harrow body is an acute angle, and the included angle of the windward front end of the harrow body is less than 20°.

3. The measuring device of claim 1, wherein, The harrow body further comprises a tail connecting end for being connected with the displacement unit, and the windward front end, the middle connecting end and the tail connecting end are sequentially connected as a whole.

4. The measuring device of claim 1, wherein, The connecting support plate is fixedly connected with the support of the wind tunnel test section.

5. The measuring device of claim 1, wherein, The test harrow unit further comprises a fixed connecting piece, and the middle connecting end is further provided with a fixed mounting hole for connecting the harrow body with the displacement unit; The fixed connecting piece can pass through the fixed mounting hole, and the harrow body is connected with the translation table through the fixed connecting piece, and the translation table can drive the test harrow unit to move synchronously.

6. The measuring device of claim 5, wherein, The probe positioning piece and the fixed connecting piece are one or more of bolts and screws.

7. The measuring device according to any one of claims 1 to 6, characterized in that The displacement unit further comprises a limiting block, the limiting block is arranged on the bottom fixed seat, the bottom fixed seat can provide support for the limiting block, the limiting block is a group, the limiting blocks are respectively located on both sides of the translation table, and the limiting blocks can be used for zero position confirmation and safety protection during operation of the translation table.

8. The measuring device of claim 1, wherein, The upper end surface of the connecting support plate is a mounting plane for being connected with the displacement unit; the connecting support plate is respectively provided with a pipeline fastening hole for connecting a probe pipeline, a positioning pin hole for cooperating with a positioning pin, and a fastening bolt hole for cooperating with a connecting bolt to realize connection of the connecting support plate with the support of the wind tunnel test section. The connecting support plate is connected with the support of the wind tunnel test section through a bolt or a pin.

9. A method of measuring wing tip vortex of an aircraft using the measuring device according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: (1) taking the center of the inlet of the test section as the coordinate axis origin; the X-axis is the longitudinal body axis, along the axial direction of the test section, and the reverse airflow is positive; the Y-axis is in the vertical plane and perpendicular to the X-axis, and upward is positive; the Z-axis is perpendicular to the X-axis and the Y-axis, and the right-hand rule is adopted for determination; (2) a test model is arranged on the side wall of the inlet of the test section, and the test model is adjusted according to the set requirements; (3) the test probe is passed through the probe mounting hole on the harrow body and arranged on the harrow body, so as to ensure that the test probe is firmly mounted on the harrow body, and the relative position between the test probe and the harrow body is fixed by using the probe positioning hole above the harrow body, thereby forming a test harrow unit; (4) the stepping motor, the sliding assembly and the limiting block in the displacement unit are respectively mounted on the support assembly, the support assembly is fixedly connected with the connecting support plate, then the screw lever is passed through the lever nut connected with the translation table, and the screw lever is connected with the output shaft of the stepping motor; (5) the test harrow unit is fixed on the translation table, and the assembly of the aircraft wing tip vortex flow measuring device is completed; (6) the aircraft wing tip vortex flow measuring device is connected with the support of the wind tunnel test section; (7) the longitudinal position of the probe head of the test probe is adjusted to reach the set position; (8) the wind tunnel is started. (9) After the flow field is stable, the test rake unit is moved to a set position in the normal direction by the wind tunnel test section support, probe data at the current position is collected, and local airflow direction data is obtained; the lateral position of the test rake unit is moved to a set position by the translation table, probe data at the current position is collected, and local airflow direction data is obtained; (10) Airflow direction tests at different positions are completed according to defined intervals and test ranges; (11) All test position measurements are completed, and the wind tunnel is stopped; (12) Streamlines are drawn according to the moving test grid points, and the pre-vehicle tail vortex flow field is reconstructed.

10. The measurement method according to claim 9, characterized by, The wind tunnel test section support is a wind tunnel test section middle support.

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