Test system and method for accurately measuring aerodynamic force of whole ducted fan and multiple parts

Abstract

The invention provides a test system and method for accurately measuring aerodynamic force of a whole ducted fan and multiple parts. The test system comprises a ducted static assembly, a rotating assembly, a power assembly, a support assembly and a measuring assembly. The measuring assembly comprises a thrust torque sensor, a first box type balance and a second box type balance. The device is applied to wind tunnel internal / external tests for accurately testing the propulsion performance of the high-power ducted fan of an aircraft, and the aerodynamic performance of the whole ducted fan and multiple parts can be accurately obtained by designing the double-box balance and the thrust torque sensor; the performance of the ducted fan and the contribution degree and the influence rule of each part on the overall performance of the ducted fan are comprehensively researched, so that the improvement of related design methods and levels is further promoted; besides, by improving the test system, nonlinear pneumatic interference caused by a model supporting structure can be effectively reduced, and the accuracy of a ducted fan performance test result is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of experimental aerodynamics, and in particular relates to a test system and method for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components. Background Art

[0002] As a key device for propulsion or attitude control of low-speed aircraft, the ducted fan needs to be tested for its aerodynamic performance to ensure its working reliability. At present, wind tunnel testing is the most reliable means of verifying the performance of ducted fans.

[0003] In the prior art, the ducted fan performance wind tunnel test method generally uses a single balance to test the overall aerodynamic performance of the ducted fan, which has the following main shortcomings: (1) The measured ducted fan performance parameters are relatively small, which is not conducive to the study of the flow mechanism and performance optimization design of the ducted fan; (2) When conducting the ducted fan performance wind tunnel test, the nonlinear aerodynamic interference caused by the model support structure is large, resulting in a certain deviation in the ducted fan performance test results, thereby reducing the accuracy of the ducted fan performance test results. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides a test system and method for accurately measuring the aerodynamic force of the ducted fan as a whole and multiple components, which can effectively solve the above problems.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention provides a test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, comprising a ducted static component (100), a rotating component (200), a power component (300), a bracket component (400) and a measuring component (500);

[0007] The support assembly (400) includes a test platform (401), a duct base (402) and a test system base (403); the measurement assembly (500) includes a thrust torque sensor (501), a first box balance (502) and a second box balance (503);

[0008] The test system base (403) is vertically arranged above the ground; the first box balance (502) is installed on the top of the test system base (403); the horizontally arranged test platform (401) is fixedly installed on the top of the first box balance (502); the second box balance (503) is installed inside the test platform (401); the duct static component (100) is fixedly installed on the top of the second box balance (503) through the duct base (402); the rotating component (200) is supported and installed on the top of the test platform (401), and one end of the rotating component (200) is connected to the power component (300) through the thrust torque sensor (501), and the rotating component (200) is driven to rotate by the power component (300).

[0009] Preferably, the duct static assembly (100) comprises a duct (101), a fairing arm (102) and a nacelle (103);

[0010] The duct base (402) is fixedly installed at the bottom of the duct (101), and the duct base (402) is fixed on the second box balance (503); the nacelle (103) is horizontally arranged at the axial center of the duct (101), and a plurality of the rectifying arms (102) are radially dispersedly arranged in the duct (101), and one end of the rectifying arm (102) is fixed to the inner wall of the duct (101), and the other end is fixed to the outer wall of the nacelle (103), so that the nacelle (103) is suspended and fixed by the duct (101) and the rectifying arm (102).

[0011] Preferably, the rotating assembly (200) comprises a rotating shaft (201), blades (202) and a hub (203);

[0012] The rotating shaft (201) is horizontally arranged to pass through the cavity of the nacelle (103) and the center of the duct (101); one end of the rotating shaft (201) is connected to the power assembly (300) through the thrust torque sensor (501), and the rotating shaft (201) is driven to rotate by the power assembly (300); inside the duct (101), and located on one side of each of the rectifying arms (102), a plurality of blades (202) are dispersedly arranged along the radial direction of the duct (101); one end of the blade (202) has a gap with the inner wall of the duct (101), and the other end of the blade (202) is fixed to the rotating shaft (201) through the hub (203); when the rotating shaft (201) rotates, the blade (202) is driven to rotate synchronously through the hub (203).

[0013] Preferably, the blade (202) is a blade with adjustable pitch angle.

[0014] Preferably, the hub (203) comprises a hub front block (2031), a hub rear block (2032), a hub fastening bolt (2033) and a hub fixing nut (2034);

[0015] The rotating shaft (201) is processed to form a stepped shaft at a position where the propeller hub (203) is installed, and an external thread is processed on one side of the stepped shaft;

[0016] The front hub block (2031) and the rear hub block (2032) are sequentially inserted into the outside of the stepped shaft, and the opposite sides of the front hub block (2031) and the rear hub block (2032) are each provided with a plurality of grooves along the circumferential direction; the grooves of the front hub block (2031) and the grooves of the rear hub block (2032) are butted against each other to form a stepped cylindrical groove matching the root of the blade (202); after the root of the blade (202) is embedded in the stepped cylindrical groove, the blade (202) is fastened by the hub fastening bolt (203 3) The front block (2031) and the rear block (2032) of the hub are fastened to each other, thereby achieving fixation between the blade (202) and the hub (203); on the rear side of the rear block (2032) of the hub, the hub fixing nut (2034) is screwed along the external thread of the step shaft, so that the front block (2031) and the rear block (2032) of the hub are fastened against the shoulder of the step shaft, thereby achieving fixation between the hub (203) and the rotating shaft (201).

[0017] Preferably, the rotating assembly (200) further comprises a propeller cap (204) and a propeller cap fixing screw (205);

[0018] The propeller cap (204) is sleeved on the outside of the rotating shaft (201), one end of the rotating shaft (201) is fixed to the propeller hub (203) through the propeller cap fixing screw (205), and the propeller cap (204) and the nacelle (103) are respectively located on two sides of the propeller hub (203);

[0019] The propeller cap (204) and the nacelle (103) are both shaped such that their diameters gradually decrease as they move away from the center of the duct (101).

[0020] Preferably, the support assembly (400) further comprises: a bearing support (404), a bearing-sensor support (405) and a motor support (406); the bearing support (404), the bearing-sensor support (405) and the motor support (406) are respectively fixedly mounted on the test platform (401);

[0021] The rotating assembly (200) further comprises: a first bearing (206), a second bearing (207), a first diaphragm coupling (208) and a second diaphragm coupling (209);

[0022] The first bearing (206) is assembled and installed at one end of the rotating shaft (201) away from the thrust torque sensor (501), and the first bearing (206) is arranged on the upper surface of the bearing support (404), and the first bearing (206) is supported by the bearing support (404);

[0023] After the second bearing (207) is installed at one end of the rotating shaft (201) close to the thrust torque sensor (501), the end of the rotating shaft (201) is connected to one end of the thrust torque sensor (501) through the first diaphragm coupling (208); the other end of the thrust torque sensor (501) is connected to the output end of the power assembly (300) through the second diaphragm coupling (209);

[0024] The second bearing (207) and the thrust torque sensor (501) are arranged on the bearing-sensor support (405), and the second bearing (207) and the thrust torque sensor (501) are supported by the bearing-sensor support (405);

[0025] The power assembly (300) is arranged on the motor support (406), and the power assembly (300) is supported by the motor support (406).

[0026] Preferably, the power assembly (300) comprises a drive motor (301) and a motor fairing (302) for reducing aerodynamic interference of the drive motor (301);

[0027] The output shaft of the driving motor (301), the thrust torque sensor (501) and the rotating shaft (201) are coaxially arranged.

[0028] Preferably, the first box balance (502) and the second box balance (503) are arranged alternately in the vertical direction.

[0029] The present invention also provides a test method for a test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, comprising the following steps:

[0030] Step S1, determining the test conditions of this test, including: the pitch angle of the blade (202), the rotation speed of the power assembly (300) and the incoming wind speed;

[0031] Step S2, performing a ducted fan wind tunnel test according to the test conditions; and during the ducted fan wind tunnel test, the thrust torque sensor (501), the first cassette balance (502) and the second cassette balance (503) collect test data in real time;

[0032] Step S3, analyzing the collected test data to determine the overall aerodynamic performance parameters and component aerodynamic performance parameters of the ducted fan in this test, specifically including:

[0033] Step S3.1, establishing a coordinate system of the second cassette balance (503): taking the center of the second cassette balance (503) as the origin, taking the vertical upward direction as the positive direction of the Y axis, taking the horizontal direction toward the power assembly (300) as the positive direction of the X axis, and determining the Z axis according to the right-hand rule, thereby establishing the coordinate system of the second cassette balance (503);

[0034] The coordinate system of the first box balance (502) is established by taking the center of the first box balance (502) as the origin, taking the vertical upward direction as the positive direction of the Y axis, taking the horizontal direction toward the power assembly (300) as the positive direction of the X axis, and determining the Z axis according to the right-hand rule, thereby establishing the coordinate system of the first box balance (502);

[0035] Step S3.2, the second cassette balance (503) collects the forces and moments along its three coordinate axes, which are: force F XA 、F YA 、F ZA , torque MF XA MF YA MF ZA ;

[0036] The first box balance (502) collects the forces and moments along its three coordinate axes, which are: XB 、F YB 、F ZB , torque MF XB MF YB MF ZB ;

[0037] The thrust torque sensor (501) collects and obtains the axial thrust T0 and power P0;

[0038] Step S3.3, the overall aerodynamic performance parameters include: total thrust T, shaft power P, efficiency η1 when the incoming wind speed is greater than 0, and force efficiency η2 when the incoming wind speed is 0, which are determined by the following formulas:

[0039]

[0040] P=P0

[0041]

[0042] Where: V is the incoming wind speed; the force efficiency η2 when the incoming wind speed is 0 is specifically the propulsion efficiency of the ducted fan under static thrust state;

[0043] The aerodynamic performance parameters of the component include blade thrust, duct and fairing arm thrust; wherein the blade thrust is equal to the axial thrust T0 collected by the thrust torque sensor (501); the duct and fairing arm thrust is equal to the force F collected by the second cassette balance (503) XA .

[0044] The test system and method for accurately measuring the aerodynamic force of the entire ducted fan and multiple components provided by the present invention have the following advantages:

[0045] The present invention provides a test system and method for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, which are applied to internal / external wind tunnel tests for accurately testing the propulsion performance of high-power ducted fans of aircraft. By designing a double-box balance plus a thrust torque sensor, the aerodynamic force performance of the ducted fan as a whole and multiple components can be accurately obtained, thereby providing more ducted fan performance parameters, which is conducive to a comprehensive study of the ducted fan performance and the contribution and influence of each component on the overall performance of the ducted fan, thereby further promoting the improvement of related design methods and levels; in addition, through the improvement of the test system, the nonlinear aerodynamic interference caused by the model support structure can be effectively reduced, and the accuracy of the ducted fan performance test results can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0047] Figure 1 A schematic diagram of the overall structure of a test system for accurately measuring the aerodynamic forces of a ducted fan as a whole and multiple components provided by the present invention;

[0048] Figure 2 An assembly diagram of a portion of the structure of the rotating assembly and the ducted static assembly provided by the present invention;

[0049] Figure 3 An exploded view of a portion of the structure of the rotating assembly provided by the present invention;

[0050] Figure 4 An assembly diagram of the rotating shaft, blades and hub provided by the present invention;

[0051] Figure 5 A three-dimensional diagram of a partial structure of a bracket assembly provided by the present invention;

[0052] Figure 6 This is a schematic diagram of the coordinate system of two box balances in the embodiment provided by the present invention.

[0053] In the figure:

[0054] 100, duct static assembly; 101, duct; 102, fairing arm; 103, nacelle;

[0055] 200, rotating assembly; 201, rotating shaft; 202, blade; 203, propeller hub; 2031, propeller hub front block; 2032, propeller hub rear block; 2033, propeller hub fastening bolt; 2034, propeller hub fixing nut; 204, propeller cap; 205, propeller cap fixing screw; 206, first bearing; 207, second bearing; 208, first diaphragm coupling; 209, second diaphragm coupling;

[0056] 300, power assembly; 301, drive motor; 302, motor fairing;

[0057] 400, bracket assembly; 401, test platform; 402, duct base; 403, test system base; 404, bearing support; 405, bearing-sensor support; 406, motor support;

[0058] 500, measuring component; 501, thrust torque sensor; 502, first cassette balance; 503, second cassette balance. DETAILED DESCRIPTION

[0059] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] The present invention provides a test system and method for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, which are applied to internal / external wind tunnel tests for accurately testing the propulsion performance of high-power ducted fans of aircraft. By designing a double-box balance plus a thrust torque sensor, the aerodynamic force performance of the ducted fan as a whole and multiple components can be accurately obtained, thereby providing more ducted fan performance parameters, which is conducive to a comprehensive study of the ducted fan performance and the contribution and influence of each component on the overall performance of the ducted fan, thereby further promoting the improvement of related design methods and levels; in addition, through the improvement of the test system, the nonlinear aerodynamic interference caused by the model support structure can be effectively reduced, and the accuracy of the ducted fan performance test results can be improved.

[0061] See also Figure 1 to Figure 6 The present invention provides a test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, including a ducted static component 100, a rotating component 200, a power component 300, a bracket component 400 and a measuring component 500;

[0062] The support assembly 400 includes a test platform 401, a duct base 402 and a test system base 403; the measurement assembly 500 includes a thrust torque sensor 501, a first box balance 502 and a second box balance 503;

[0063] The test system base 403 is vertically arranged above the ground; the first box balance 502 is installed on the top of the test system base 403; the horizontally arranged test platform 401 is fixedly installed on the first box balance 502; the second box balance 503 is installed inside the test platform 401; the duct static component 100 is fixedly installed on the second box balance 503 through the duct base 402; the rotating component 200 is supported and installed on the test platform 401, and one end of the rotating component 200 is connected to the power component 300 through the thrust torque sensor 501, and the rotating component 200 is driven to rotate by the power component 300.

[0064] As a preferred embodiment, the first cassette balance 502 and the second cassette balance 503 are arranged alternately in the vertical direction.

[0065] The following is a detailed introduction to the duct static assembly 100, the rotating assembly 200, the power assembly 300 and the bracket assembly 400:

[0066] (I) Ducted static assembly 100:

[0067] The duct static assembly 100 includes a duct 101, a fairing arm 102 and a nacelle 103;

[0068] A duct base 402 is fixedly installed at the bottom of the duct 101, and the duct base 402 is fixed on the second cassette balance 503; a nacelle 103 is horizontally arranged at the axial center of the duct 101, and a plurality of rectifying arms 102 are radially dispersedly arranged in the duct 101, and one end of the rectifying arm 102 is fixed to the inner wall of the duct 101, and the other end is fixed to the outer wall of the nacelle 103, so that the nacelle 103 is suspended and fixed by the duct 101 and the rectifying arm 102.

[0069] (ii) Rotating assembly 200:

[0070] The rotating assembly 200 includes a rotating shaft 201, blades 202 and a hub 203;

[0071] The rotating shaft 201 is horizontally arranged to pass through the cavity of the nacelle 103 and the center of the duct 101. One end of the rotating shaft 201 is connected to the power assembly 300 through the thrust torque sensor 501, and the rotating shaft 201 is driven to rotate by the power assembly 300; inside the duct 101, and on one side of each fairing arm 102, a plurality of blades 202 are dispersedly arranged along the radial direction of the duct 101, one end of the blade 202 has a gap with the inner wall of the duct 101, and the other end of the blade 202 is fixed to the rotating shaft 201 through the hub 203; when the rotating shaft 201 rotates, the blade 202 is driven to rotate synchronously through the hub 203.

[0072] In the present invention, the blade 202 is an adjustable pitch blade, and the pitch angle can be changed without disassembling the components, thereby facilitating the completion of tests at various pitch angles and facilitating the comparison of test results at various pitch angles. Figure 2 to Figure 4 The hub 203 includes a hub front block 2031, a hub rear block 2032, a hub fastening bolt 2033 and a hub fixing nut 2034;

[0073] The rotating shaft 201 is processed to form a stepped shaft at the position where the propeller hub 203 is installed, and an external thread is processed on one side of the stepped shaft;

[0074] The front hub block 2031 and the rear hub block 2032 are sequentially inserted into the outside of the step shaft, and the opposite sides of the front hub block 2031 and the rear hub block 2032 are each provided with a plurality of grooves along the circumferential direction; the grooves of the front hub block 2031 and the rear hub block 2032 are butted against each other to form a stepped cylindrical groove matching the root of the blade 202, and after the root of the blade 202 is embedded in the stepped cylindrical groove, the front hub block 2031 and the rear hub block 2032 are fastened by the hub fastening bolts 2033, thereby achieving fixation between the blade 202 and the hub 203; on the rear side of the rear hub block 2032, the hub fixing nut 2034 is screwed along the external thread of the step shaft, so that the front hub block 2031 and the rear hub block 2032 are fastened against the shoulder of the step shaft, thereby achieving fixation between the hub 203 and the rotating shaft 201.

[0075] Therefore, when the pitch angle of the blade 202 needs to be adjusted, the blade 202 can be rotated by only loosening the hub fastening bolt 2033 to adjust the pitch angle of the blade 202. Then, the hub fastening bolt 2033 can be tightened.

[0076] In the present invention, the rotating assembly 200 further includes a propeller cap 204 and a propeller cap fixing screw 205; the propeller cap 204 is sleeved on the outside of the rotating shaft 201, one end of the rotating shaft 201 is fixed to the propeller hub 203 by the propeller cap fixing screw 205, and the propeller cap 204 and the nacelle 103 are respectively located on both sides of the propeller hub 203;

[0077] In specific implementation, the propeller cap 204 can be formed by CNC processing of 7075 aluminum alloy to reduce weight; the rotating shaft 201 and the propeller hub 203 are formed by CNC processing of 30CrMnSiA steel and heat treated to improve strength. The propeller cap 204 and the nacelle 103 are both shaped in a direction away from the center of the duct 101, and their diameters gradually decrease. This design is a fluid mechanics design that can reduce its own aerodynamic resistance and improve the accuracy of the aerodynamic performance parameters obtained by the test.

[0078] (III) Bracket assembly 400:

[0079] The bracket assembly 400 also includes: a bearing support 404, a bearing-sensor support 405 and a motor support 406; the bearing support 404, the bearing-sensor support 405 and the motor support 406 are fixedly installed on the test platform 401 respectively; in the specific implementation, the bracket assembly 400 is formed by welding 45# steel plate.

[0080] The rotating assembly 200 further includes: a first bearing 206, a second bearing 207, a first diaphragm coupling 208 and a second diaphragm coupling 209;

[0081] The first bearing 206 is mounted on one end of the rotating shaft 201 away from the thrust torque sensor 501 . The first bearing 206 is disposed on the bearing support 404 and supported by the bearing support 404 .

[0082] After the second bearing 207 is installed at one end of the rotating shaft 201 close to the thrust torque sensor 501, the end of the rotating shaft 201 is connected to one end of the thrust torque sensor 501 through the first diaphragm coupling 208; the other end of the thrust torque sensor 501 is connected to the output end of the power assembly 300 through the second diaphragm coupling 209;

[0083] The second bearing 207 and the thrust torque sensor 501 are disposed on the bearing-sensor support 405, and the second bearing 207 and the thrust torque sensor 501 are supported by the bearing-sensor support 405;

[0084] The power assembly 300 is disposed on the motor support 406 , and the power assembly 300 is supported by the motor support 406 .

[0085] In practical applications, the first bearing 206 and the second bearing 207 at both ends of the rotating shaft 201 can adopt cylindrical roller bearings without retaining edges. This type of bearing does not limit the axial displacement of the rotating shaft 201, ensuring axial freedom, thereby improving the accuracy of the torque sensor 501 in measuring blade thrust.

[0086] In the present application, the thrust torque sensor 501 is arranged between the power assembly 300 and the rotating shaft 201 to directly measure the thrust of the blades. The thrust torque sensor 501 is arranged on the bearing-sensor support 405, one end of which is connected to the motor shaft of the power assembly 300 through a flange, and the other end is connected to one end of the rotating shaft 201 through a flange. In addition, diaphragm couplings are installed at both ends of the thrust torque sensor 501 to compensate for the coaxiality installation tolerance between the thrust torque sensor 501, the rotating shaft 201 and the output shaft of the power assembly 300, thereby protecting the thrust torque sensor 501.

[0087] (IV) Power assembly 300:

[0088] The power assembly 300 includes a driving motor 301 and a motor fairing 302 for reducing aerodynamic interference of the driving motor 301;

[0089] The output shaft of the driving motor 301 , the thrust torque sensor 501 and the rotating shaft 201 are coaxially arranged.

[0090] The present invention also provides a test method for a test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, comprising the following steps:

[0091] Step S1, determining the test conditions of this test, including: the pitch angle of the blade 202, the rotation speed of the power assembly 300 and the incoming wind speed;

[0092] Step S2, performing a ducted fan wind tunnel test according to the test conditions; and during the ducted fan wind tunnel test, the thrust torque sensor 501, the first cassette balance 502 and the second cassette balance 503 collect test data in real time;

[0093] Step S3, analyzing the collected test data to determine the overall aerodynamic performance parameters and component aerodynamic performance parameters of the ducted fan in this test, specifically including:

[0094] Step S3.1, establishing the coordinate system of the second cassette balance 503: taking the center of the second cassette balance 503 as the origin, taking the vertical upward direction as the positive direction of the Y axis, taking the horizontal direction toward the power assembly 300 as the positive direction of the X axis, and determining the Z axis according to the right-hand rule, thereby establishing the coordinate system of the second cassette balance 503;

[0095] The coordinate system of the first box balance 502 is established as follows: the center of the first box balance 502 is taken as the origin, the vertical upward direction is taken as the positive direction of the Y axis, the horizontal direction toward the power assembly 300 is taken as the positive direction of the X axis, and the Z axis is determined according to the right-hand rule, thereby establishing the coordinate system of the first box balance 502;

[0096] Step S3.2: The second cassette balance 503 collects the forces and moments along its three coordinate axes, which are: force F XA 、F YA 、F ZA , torque MF XA MF YA MF ZA ;

[0097] The first box balance 502 collects the forces and moments along its three coordinate axes, which are: XB 、F YB 、F ZB , torque MF XB MF YB MF ZB ;

[0098] The thrust torque sensor 501 collects and obtains the axial thrust T0 and power P0;

[0099] Step S3.3, the overall aerodynamic performance parameters include: total thrust T, shaft power P, efficiency η1 when the incoming wind speed is greater than 0, and force efficiency η2 when the incoming wind speed is 0, which are determined by the following formulas:

[0100]

[0101] P=P0

[0102]

[0103] Where: V is the incoming wind speed; the force efficiency η2 when the incoming wind speed is 0 is specifically the propulsion efficiency of the ducted fan under static thrust state;

[0104] The aerodynamic performance parameters of the components include blade thrust, duct and fairing arm thrust; wherein the blade thrust is equal to the axial thrust T0 collected by the thrust torque sensor 501; the duct and fairing arm thrust is equal to the force F collected by the second cassette balance 503 XA .

[0105] An example is listed below:

[0106] The present invention provides a test system and method for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, which is applied to a ducted fan model wind tunnel test. During the wind tunnel test, the test system operates well and the test data is accurate and reliable. The following describes a specific implementation of the present invention using a ground static thrust test of a certain type of ducted fan model as an example.

[0107] (I) Test model

[0108] The main body of the experimental ducted fan model includes a duct static component 100, a rotating component 200, a power component 300, a bracket component 400 and a measuring component 500. The duct static component 100 includes a duct 101, a fairing arm 102 and a nacelle 103; the rotating component 200 includes a rotating shaft 201, blades 202, a hub 203 and a propeller cap 204; wherein: the duct 101, the fairing arm 102 and the nacelle 103 are made of carbon steel, fiberglass, beech and other materials; the blades 202 are 6 pieces, made of 7075 aluminum alloy, and the pitch angle is variable. The ducted fan test model is as follows Figure 1 shown.

[0109] The measurement assembly 500 includes a thrust torque sensor 501 , a first cassette balance 502 , and a second cassette balance 503 .

[0110] The first box balance 502 and the second box balance 503 are six-component box balances. The model of the first box balance 502 is TP1201 six-component box balance, and the model of the second box balance 503 is TP2001 six-component box balance. The first box balance 502 is used to measure the overall aerodynamic performance parameters of the ducted fan; the second box balance 503 is used to measure the aerodynamic performance parameters of the components.

[0111] The thrust torque sensor 501 is a specially customized product that can measure thrust and torque at one end at the same time. The thrust torque sensor 501 adopts the principle of strain electrical measurement. When the strain axis is slightly deformed by force, the resistance of the strain gauge attached to the strain axis changes accordingly. The change in the resistance of the strain gauge is converted into a change in the voltage signal for measurement through the measuring bridge. The voltage signal acquisition and display reading of the thrust torque sensor 501 are completed by the matching measuring instrument.

[0112] Since the thrust torque sensor 501 has high requirements on the coaxiality of the rotating shaft, in order to prevent the thrust torque sensor 501 from being damaged, diaphragm couplings are connected at both ends. This test uses KTS93-24-F88 diaphragm couplings, and the interface is customized with a keyway at one end and a flange at the other end.

[0113] The driving motor 301 of the power assembly 300 adopts a high power density motor, specifically a 100 kW high power density motor, which is used to drive the blades 202 to rotate.

[0114] (II) Test preparation and process

[0115] The preparatory work before the test includes: test model inspection and acceptance, dynamic / static balance test of rotating component 202, assembly and adjustment test of duct static component 100, rotating component 200, power component 300 and bracket component 400, static loading test of thrust torque sensor 501, first cassette balance 502 and second cassette balance 503, etc.

[0116] The test content includes repeatability accuracy test and ducted fan model propulsion performance test under specified working conditions.

[0117] Test model inspection and acceptance: Before the test, the key dimensions and profiles of the test model need to be inspected. For example, the blades need to pass the mass, length, root diameter measurement, and profile sample inspection, the duct needs to pass the chord length, inner diameter, tail diameter measurement, and profile sample inspection, and the fairing arm needs to pass the profile sample inspection. The wind tunnel test model processing accuracy must meet the requirements of GJB180A-2006 "Low-speed Wind Tunnel Aircraft Model Design Guidelines".

[0118] Dynamic / static balance test of rotating assembly: To ensure the safety of the test, high-speed rotating devices must pass the dynamic / static balance test before they can be put into use. The dynamic / static balance test is completed on a dynamic balance test bench. In this test, the rotating assembly 200 includes a rotating shaft 201, blades 202, a hub 203, and a propeller cap 204. The general steps of the dynamic / static balance test are: After assembling the rotating assembly 200 into a whole, fix it on the dynamic balance test bench, start the test bench to make the rotating assembly 200 start to rotate, and the test bench will display the dynamic imbalance and angle of the rotating assembly 200. At this time, counterweights or weight reduction treatments are required at appropriate positions to reduce the dynamic imbalance. Repeated debugging can improve the dynamic balance quality of the rotating assembly 200, thereby reducing the vibration of the rotating assembly 200 during the test.

[0119] Test model and bench assembly joint test: The joint test is to ensure that the test system components can be assembled without interference and the test system can operate smoothly. Since there are multiple connection structures from the end of the shaft to the drive motor in this test system, the debugging focus is to ensure the coaxiality of each section. Finally, it is necessary to pass several test runs to reach the highest speed required for the test, and the test system can only be operated normally before the formal test can be carried out.

[0120] Static loading test of thrust torque sensor 501, first cassette balance 502 and second cassette balance 503: Static loading of thrust torque sensor 501, first cassette balance 502 and second cassette balance 503 is a means to ensure that the readings of each thrust torque sensor 501, first cassette balance 502 and second cassette balance 503 are normal before the formal test. The specific operation is: when the test system is not started, several standard weights are added to each thrust torque sensor 501, first cassette balance 502 and second cassette balance 503 in each direction, and the readings are checked on the data acquisition system at the same time. Usually, the first cassette balance 502 and second cassette balance 503 need to be statically loaded in three coordinate axes, and the thrust torque sensor 501 needs to be loaded with thrust and torque for testing.

[0121] The test is carried out using the test system and method for accurately measuring the aerodynamic force of the ducted fan as a whole and multiple components provided by the present invention.

[0122] (III) Experimental data error analysis

[0123] The accuracy of wind tunnel test is repeatability accuracy. The test is evaluated by repeating the test many times under the same working conditions and collecting test data, and calculating the root mean square of the test data to evaluate the test accuracy, that is, the root mean square error. In engineering applications, the root mean square error of wind tunnel test is usually required to be ≤1%. In this test, the repeatability test was repeated 7 times, and the root mean square error of the thrust coefficient was 0.21%, and the root mean square error of the shaft power coefficient was 0.14%, reaching the industry's excellent level.

[0124] (IV) Conclusion

[0125] The ducted fan test system has successfully completed multiple ducted fan model wind tunnel test tasks. During the test, the system operated normally, and the box balances and thrust torque sensors successfully measured the overall and component aerodynamic forces, successfully obtaining the overall and component aerodynamic performance test data of the ducted fan model, and the accuracy of the test results met the index requirements.

[0126] The present invention provides a test system and method for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, which has the following advantages:

[0127] 1. The ducted fan test system and method place the thrust torque sensor between the motor output end and the rotating shaft. The measured blade thrust test value is not affected by factors such as the aerodynamic interference of the bracket and the conduction of force, which effectively reduces the nonlinear interference problem of the test bench.

[0128] 2. The ducted fan test system and method can not only accurately measure the overall performance parameters of the ducted fan model, such as total thrust, shaft power, efficiency, etc., but also accurately measure the aerodynamic parameters of components such as blade thrust, duct and fairing arm thrust, and obtain the mutual influence rules between components and their contribution to the overall performance. The test data can provide support for the study of complex interference flow mechanisms of multiple components of ducted fans and the coupled design of multiple components of high-performance ducted fans, thereby improving the design level.

[0129] The present invention supports multi-operating condition (rotation speed and pitch angle are adjustable) and multi-configuration (partial components are replaceable) ducted fan tests and is flexible and convenient to use.

[0130] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components, characterized in that: It comprises a ducted static component (100), a rotating component (200), a power component (300), a support component (400) and a measuring component (500); The support assembly (400) includes a test platform (401), a duct base (402) and a test system base (403); the measurement assembly (500) includes a thrust torque sensor (501), a first box balance (502) and a second box balance (503); The test system base (403) is vertically arranged above the ground; the first box balance (502) is installed on the top of the test system base (403); the horizontally arranged test platform (401) is fixedly installed on the top of the first box balance (502); the second box balance (503) is installed inside the test platform (401); the duct static component (100) is fixedly installed on the top of the second box balance (503) through the duct base (402); the rotating component (200) is supported and installed on the top of the test platform (401), and one end of the rotating component (200) is connected to the power component (300) through the thrust torque sensor (501), and the rotating component (200) is driven to rotate by the power component (300).

2. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 1, characterized in that: The duct static assembly (100) comprises a duct (101), a fairing arm (102) and a nacelle (103); The duct base (402) is fixedly installed at the bottom of the duct (101), and the duct base (402) is fixed on the second box balance (503); the nacelle (103) is horizontally arranged at the axial center of the duct (101), and a plurality of the rectifying arms (102) are radially dispersedly arranged in the duct (101), and one end of the rectifying arm (102) is fixed to the inner wall of the duct (101), and the other end is fixed to the outer wall of the nacelle (103), so that the nacelle (103) is suspended and fixed by the duct (101) and the rectifying arm (102).

3. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 2, characterized in that: The rotating assembly (200) comprises a rotating shaft (201), blades (202) and a hub (203); The rotating shaft (201) is horizontally arranged to pass through the cavity of the nacelle (103) and the center of the duct (101); one end of the rotating shaft (201) is connected to the power assembly (300) through the thrust torque sensor (501), and the rotating shaft (201) is driven to rotate by the power assembly (300); inside the duct (101), and located on one side of each of the rectifying arms (102), a plurality of blades (202) are dispersedly arranged along the radial direction of the duct (101); one end of the blade (202) has a gap with the inner wall of the duct (101), and the other end of the blade (202) is fixed to the rotating shaft (201) through the hub (203); when the rotating shaft (201) rotates, the blade (202) is driven to rotate synchronously through the hub (203).

4. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 3, characterized in that: The blade (202) is a blade with adjustable pitch angle.

5. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 4, characterized in that: The hub (203) comprises a hub front block (2031), a hub rear block (2032), a hub fastening bolt (2033) and a hub fixing nut (2034); The rotating shaft (201) is processed to form a stepped shaft at a position where the propeller hub (203) is installed, and an external thread is processed on one side of the stepped shaft; The front hub block (2031) and the rear hub block (2032) are sequentially inserted into the outside of the stepped shaft, and the opposite sides of the front hub block (2031) and the rear hub block (2032) are each provided with a plurality of grooves along the circumferential direction; the grooves of the front hub block (2031) and the grooves of the rear hub block (2032) are butted against each other to form a stepped cylindrical groove matching the root of the blade (202); after the root of the blade (202) is embedded in the stepped cylindrical groove, the blade (202) is fastened by the hub fastening bolt (203 3) The front block (2031) and the rear block (2032) of the hub are fastened to each other, thereby achieving fixation between the blade (202) and the hub (203); on the rear side of the rear block (2032) of the hub, the hub fixing nut (2034) is screwed along the external thread of the step shaft, so that the front block (2031) and the rear block (2032) of the hub are fastened against the shoulder of the step shaft, thereby achieving fixation between the hub (203) and the rotating shaft (201).

6. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 3, characterized in that: The rotating assembly (200) further comprises a propeller cap (204) and a propeller cap fixing screw (205); The propeller cap (204) is sleeved on the outside of the rotating shaft (201), one end of the rotating shaft (201) is fixed to the propeller hub (203) through the propeller cap fixing screw (205), and the propeller cap (204) and the nacelle (103) are respectively located on two sides of the propeller hub (203); The propeller cap (204) and the nacelle (103) are both shaped such that their diameters gradually decrease as they move away from the center of the duct (101).

7. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 3, characterized in that: The support assembly (400) further comprises: a bearing support (404), a bearing-sensor support (405) and a motor support (406); the bearing support (404), the bearing-sensor support (405) and the motor support (406) are respectively fixedly mounted on the test platform (401); The rotating assembly (200) further comprises: a first bearing (206), a second bearing (207), a first diaphragm coupling (208) and a second diaphragm coupling (209); The first bearing (206) is assembled and installed at one end of the rotating shaft (201) away from the thrust torque sensor (501), and the first bearing (206) is arranged on the upper surface of the bearing support (404), and the first bearing (206) is supported by the bearing support (404); After the second bearing (207) is installed at one end of the rotating shaft (201) close to the thrust torque sensor (501), the end of the rotating shaft (201) is connected to one end of the thrust torque sensor (501) through the first diaphragm coupling (208); the other end of the thrust torque sensor (501) is connected to the output end of the power assembly (300) through the second diaphragm coupling (209); The second bearing (207) and the thrust torque sensor (501) are arranged on the bearing-sensor support (405), and the second bearing (207) and the thrust torque sensor (501) are supported by the bearing-sensor support (405); The power assembly (300) is arranged on the motor support (406), and the power assembly (300) is supported by the motor support (406).

8. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 1, characterized in that: The power assembly (300) comprises a drive motor (301) and a motor fairing (302) for reducing aerodynamic interference of the drive motor (301); The output shaft of the driving motor (301), the thrust torque sensor (501) and the rotating shaft (201) are coaxially arranged.

9. A test system for accurately measuring the aerodynamic force of a ducted fan as a whole and multiple components according to claim 1, characterized in that: The first box balance (502) and the second box balance (503) are arranged alternately in a vertical direction.

10. A test method for a test system for accurately measuring aerodynamic forces of a ducted fan as a whole and multiple components as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, determining the test conditions of this test, including: the pitch angle of the blade (202), the rotation speed of the power assembly (300) and the incoming wind speed; Step S2, performing a ducted fan wind tunnel test according to the test conditions; and during the ducted fan wind tunnel test, the thrust torque sensor (501), the first cassette balance (502) and the second cassette balance (503) collect test data in real time; Step S3, analyzing the collected test data to determine the overall aerodynamic performance parameters and component aerodynamic performance parameters of the ducted fan in this test, specifically including: Step S3.1, establishing a coordinate system of the second cassette balance (503): taking the center of the second cassette balance (503) as the origin, taking the vertical upward direction as the positive direction of the Y axis, taking the horizontal direction toward the power assembly (300) as the positive direction of the X axis, and determining the Z axis according to the right-hand rule, thereby establishing the coordinate system of the second cassette balance (503); The coordinate system of the first box balance (502) is established by taking the center of the first box balance (502) as the origin, taking the vertical upward direction as the positive direction of the Y axis, taking the horizontal direction toward the power assembly (300) as the positive direction of the X axis, and determining the Z axis according to the right-hand rule, thereby establishing the coordinate system of the first box balance (502); Step S3.2, the second cassette balance (503) collects the forces and moments along its three coordinate axes, which are: force F XA 、F YA 、F ZA , torque MF XA MF YA MF ZA ; The first box balance (502) collects the forces and moments along its three coordinate axes, which are: XB 、F YB 、F ZB , torque MF XB MF YB MF ZB ; The thrust torque sensor (501) collects and obtains the axial thrust T0 and power P0; Step S3.3, the overall aerodynamic performance parameters include: total thrust T, shaft power P, efficiency η1 when the incoming wind speed is greater than 0, and force efficiency η2 when the incoming wind speed is 0, which are determined by the following formulas: P=P0 Where: V is the incoming wind speed; the force efficiency η2 when the incoming wind speed is 0 is specifically the propulsion efficiency of the ducted fan under static thrust state; The aerodynamic performance parameters of the component include blade thrust, duct and fairing arm thrust; wherein the blade thrust is equal to the axial thrust T0 collected by the thrust torque sensor (501); the duct and fairing arm thrust is equal to the force F collected by the second cassette balance (503) XA .

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