A kind of test wind tunnel test model propeller blade fatigue life test mechanism

Abstract

The present application belongs to the field of wind tunnel test model propeller testing, and particularly relates to a kind of test wind tunnel test model propeller blade fatigue life test mechanism, including mainframe, support structure, lever mechanism;The support structure is provided with blade profiling fixture;The upper end surface of mainframe is installed electric exciter, is connected with blade profiling fixture by sensor connecting rod, simulates periodic fluctuation aerodynamic force that propeller is subjected to in wind tunnel test process, provides corresponding amplitude and frequency excitation to propeller test piece;The support structure includes upper crossbeam, upper movable crossbeam, lower movable crossbeam, lower platform, two height adjusting screws, two guide columns, two swing rods;The present application fully considers the fluctuation aerodynamic force and stable centrifugal force that blade is subjected to in test process, and the present application can realize the fatigue test of different shapes and same size order blade by adjusting mechanism and reprocessing tool fixture, greatly improves the use efficiency of mechanism.

Description

Technical Field

[0001] The invention belongs to the field of propeller testing for wind tunnel test models, and in particular relates to a propeller blade fatigue life testing mechanism for testing wind tunnel test models. Background Art

[0002] Fatigue testing technologies for propeller blades, shafts, and hubs are currently developing both domestically and internationally, but these technologies are limited to propellers for aircraft, ships, and drones. These propellers are typically large, and fatigue testing facilities often target blades with a fixed profile. Unlike conventional propellers, wind tunnel test model propellers are smaller. Due to size constraints and wind tunnel testing safety considerations, the blades and shafts are often designed and manufactured as a single unit. Currently, research on adjustable fatigue testing technologies for integrated blade and shaft manufacturing is limited. For safety reasons, some wind tunnel test blades are made of carbon fiber composites. Due to the instability of the carbon fiber composite manufacturing process and the difficulty in modeling complex curved surfaces with anisotropic materials, fatigue calculations for these blades are challenging and difficult to implement. Therefore, wind tunnel test model propellers vary greatly in size and profile. Therefore, an adjustable fatigue life testing facility suitable for a variety of propeller profiles is clearly more economical. Summary of the Invention

[0003] In order to overcome the above problems, the stress conditions of the propeller structure in the wind tunnel test can be simulated on the ground, and the fatigue testing technology can be adjusted. The present invention provides the following technical solutions: a spiral blade fatigue life testing mechanism for testing wind tunnel test models, comprising a main frame, a support structure, and a lever mechanism;

[0004] The support structure includes an upper crossbeam, an upper movable crossbeam, a lower movable crossbeam, a lower platform, two height adjustment screws, two guide columns, and two rocker arms;

[0005] The upper crossbeam, upper movable crossbeam, lower movable crossbeam and lower platform are arranged in parallel and connected together by two guide columns. The upper movable crossbeam and lower movable crossbeam are adjusted in installation height by two height adjustment screws;

[0006] Two rocker supports are installed on the lower moving crossbeam, and a blade profiling fixture is connected to the two rocker supports via two rocker rods, and the blade profiling fixture clamps the blade of the propeller test piece;

[0007] The lever mechanism includes a lever, a weight suspension rod, and a hoisting weight; the lever is hinged above the upper beam, the front end of the lever is connected to the weight suspension rod, and the hoisting weight is hung at the lower end of the weight suspension rod;

[0008] An electric vibrator is installed on the main frame, and the electric vibrator is connected to the blade profiling fixture through a sensor connecting rod;

[0009] The upper end surface of the upper movable beam is provided with an upper pull rod connecting flange, the lower end of the upper pull rod is connected to the upper pull rod connecting flange through a rotatable pin shaft, and the upper end of the upper pull rod is connected to the lever.

[0010] Furthermore, the propeller handle of the propeller test piece passes through the lower movable crossbeam and is connected to the fixed connecting rod, and the bottom end of the fixed connecting rod is threadedly connected to an adjusting handwheel.

[0011] Furthermore, a pneumatic force loading limit seat is installed on the upper end surface of the upper crossbeam, and the pneumatic force loading limit seat is located below the lever.

[0012] Furthermore, the upper end surface of the main frame is an upper flat plate of the main frame, and a balance column is provided between the upper flat plate of the main frame and the lower end surface of the upper beam; a scale is provided on the balance column, and a pointer is provided on the weight boom for indicating the lever balance reading.

[0013] Furthermore, an adjustable balance weight is provided at the end of the lever.

[0014] Furthermore, a hoisting weight is hung on the lower end of the weight suspension rod via an adjustable tension spring.

[0015] Furthermore, the host frame is a box-type container, the upper end surface of the host frame is a host frame upper plane plate, the host frame upper plane plate is partially perforated, the weight suspension rod extends into the host frame through the hole, and the weight is stored in the host frame.

[0016] Furthermore, the host frame is a square box-type stainless steel container.

[0017] Furthermore, double door panels and a door lock are provided in front of the main frame.

[0018] This application has the following beneficial effects:

[0019] 1. Compared with traditional fatigue testing machines, the present invention fully considers the fluctuating aerodynamic force and stable centrifugal force that the blade is subjected to during the test process, and decouples the two in structure.

[0020] 2. Compared with conventional blade testing, the present invention can achieve fatigue testing of blades of different shapes and the same size by adjusting the mechanism and reprocessing the fixture, which greatly improves the efficiency of the mechanism.

[0021] 3. The present invention can better predict the blade life during ground testing, filling the gap in the unpredictability of blade life in wind tunnel tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the propeller fatigue life test mechanism;

[0023] Figure 2 This is a schematic diagram of blade loading in a propeller fatigue life test facility;

[0024] Figure 3 It is a schematic diagram of the lever structure of the propeller fatigue life test mechanism.

[0025] In the figure: 1-main frame, 2-electric vibrator, 3-main frame upper plane plate, 4-lever, 5-adjustable balancing weight, 6-pneumatic loading limit seat, 7-weight suspension rod, 8-ruler, 9-sensor connecting rod, 10-upper beam, 11-upper movable beam, 12-lower movable beam, 13-lower platform, 14-height adjustment screw, 15-guide column, 16-blade profiling fixture, 17-rocker, 18-propeller test piece, 19-adjustable tension spring, 20-upper pull rod, 21-upper pull rod connecting flange, 22-rocker arm support, 23-adjusting handwheel, 24-balancing column, 25-fixed connecting rod. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0027] Example 1:

[0028] Combined with attachment Figure 1-3 , the present application discloses a propeller blade fatigue life testing mechanism for testing a wind tunnel test model, comprising a main frame 1, a supporting structure, and a lever mechanism;

[0029] The support structure includes an upper crossbeam 10, an upper movable crossbeam 11, a lower movable crossbeam 12, a lower platform 13, two height adjustment screws 14, two guide columns 15, and two rocker arms 17;

[0030] The upper crossbeam 10, the upper movable crossbeam 11, the lower movable crossbeam 12, and the lower platform 13 are arranged in parallel and connected together by two guide columns 15. The upper movable crossbeam 11 and the lower movable crossbeam 12 are adjusted in installation height by two height adjustment screws 14;

[0031] Two rocker supports 22 are mounted on the lower movable crossbeam 12 , and a blade profiling fixture 16 is connected to the two rocker supports 22 via two rocker rods 17 . The blade profiling fixture 16 clamps the blade of the propeller test piece 18 .

[0032] The lever mechanism includes a lever 4, a weight suspension rod 7, and a hoisting weight; the lever 4 is hinged above the upper beam 10, the front end of the lever 4 is connected to the weight suspension rod 7, and the lower end of the weight suspension rod 7 is hung with a hoisting weight;

[0033] The main frame 1 is provided with an electric vibration exciter 2, which is connected to the blade profiling fixture 16 via a sensor connecting rod 9;

[0034] The upper end surface of the upper movable beam 11 is provided with an upper pull rod connecting flange 21 , the lower end of the upper pull rod 20 is connected to the upper pull rod connecting flange 21 via a rotatable pin shaft, and the upper end of the upper pull rod 20 is connected to the lever 4 .

[0035] Furthermore, the propeller handle of the propeller test piece 18 passes through the lower movable crossbeam 12 and is connected to the fixed connecting rod 25 , and the bottom end of the fixed connecting rod 25 is threadedly connected to the adjusting hand wheel 23 .

[0036] Furthermore, a pneumatic force loading limit seat 6 is installed on the upper end surface of the upper crossbeam 10 , and the pneumatic force loading limit seat 6 is located below the lever 4 .

[0037] Furthermore, the upper end surface of the main frame 1 is the main frame upper plane plate 3, and a balance column 24 is provided between the main frame upper plane plate 3 and the lower end surface of the upper beam 10; a scale 8 is provided on the balance column 24, and a pointer is provided on the weight suspension rod 7 for indicating the lever balance reading.

[0038] Furthermore, an adjustable balance weight 5 is provided at the end of the lever 4 .

[0039] Furthermore, a hoisting weight is hung on the lower end of the weight suspension rod 7 via an adjustable tension spring 19 .

[0040] Furthermore, the main frame 1 is a box-type container, and the upper end surface of the main frame 1 is a main frame upper flat plate 3. The main frame upper flat plate 3 is partially perforated, and the weight suspension rod 7 extends into the main frame 1 through the hole, and the weight is stored in the main frame 1.

[0041] Furthermore, the main frame 1 is a square box-type stainless steel container.

[0042] Furthermore, double door panels and a door lock are provided in front of the main frame 1 .

[0043] Working principle:

[0044] The blades of the propeller test piece 18 are connected to the blade profiling fixture 16, which can apply a preload. The blade profiling fixture 16 is connected to the electric vibrator 2. The steady-state centrifugal force is passed through the electric vibrator 2 to provide a periodic excitation force, simulating the sinusoidal fluctuating aerodynamic force to which the propeller test piece 18 is subjected during operation; the fluctuating aerodynamic force is applied through the electric vibrator 2, and the fluctuating aerodynamic force is perpendicular to the direction of the steady-state centrifugal force. The lever mechanism fixed to the upper crossbeam 10 is balanced by weights, and the blade profiling fixture 16 is pulled upward by the upper movable crossbeam 11 and the rocker 17, thereby stretching the propeller test piece 18, simulating the operation of the propeller, and providing a stable blade centrifugal force. The weight of the hoisting weight is determined based on the centrifugal force applied to the propeller test piece 18 during the wind tunnel test and the balancing condition of the lever principle. When the mechanism is overloaded, lever 4 sinks and hits the aerodynamic loading limiter 6. When the load is complex and balancing with weights alone is difficult, an adjustable balancing weight 5 is installed on the other side of lever 4 to assist in adjustment. The load provided by the weights acts on lever 4 via an adjustable tension spring 19 through a weight suspension rod 7. Lever 4 pulls upward on the upper movable beam 11, which is fixed to the upper pull rod 20. This tension is gradually transferred to the lower movable beam 12, the rocker support 22 connected to the lower movable beam, the rocker arm 17 connected to the rocker support, the blade profiling fixture 16 clamped to the rocker arm 17, and the propeller test piece 18 clamped to the blade profiling fixture 16. The upward tension applied to the propeller test piece 18 simulates the loading conditions of a wind tunnel test. The connection method at the propeller handle of the propeller test piece 18 is consistent with the wind tunnel test connection method. It passes through the hole in the center of the lower movable beam 12, does not contact the lower movable beam 12, and is directly fixed to the fixed link 25.

[0045] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A propeller blade fatigue life testing mechanism for testing wind tunnel test models, characterized in that: It includes a main frame (1), a supporting structure, and a lever mechanism; The support structure comprises an upper crossbeam (10), an upper movable crossbeam (11), a lower movable crossbeam (12), a lower platform (13), two height adjustment screws (14), two guide columns (15), and two rocker arms (17); The upper crossbeam (10), the upper movable crossbeam (11), the lower movable crossbeam (12), and the lower platform (13) are arranged in parallel and connected together through two guide columns (15). The upper movable crossbeam (11) and the lower movable crossbeam (12) are adjusted in installation height through two height adjustment screws (14); Two rocker supports (22) are installed on the lower moving crossbeam (12), and a blade profiling fixture (16) is connected to the two rocker supports (22) via two rocker rods (17). The blade profiling fixture (16) clamps the blade of the propeller test piece (18); The lever mechanism comprises a lever (4), a weight suspension rod (7), and a hoisting weight; the lever (4) is hinged above the upper crossbeam (10), the front end of the lever (4) is connected to the weight suspension rod (7), and the lower end of the weight suspension rod (7) is hung with a hoisting weight; An electric vibrator (2) is mounted on the main frame (1), and the electric vibrator (2) is connected to a blade profiling fixture (16) via a sensor connecting rod (9); The upper end surface of the upper movable crossbeam (11) is provided with an upper pull rod connecting flange (21), the lower end of the upper pull rod (20) is connected to the upper pull rod connecting flange (21) via a rotatable pin shaft, and the upper end of the upper pull rod (20) is connected to the lever (4).

2. The propeller blade fatigue life testing mechanism for testing wind tunnel test models according to claim 1, characterized in that: The propeller handle of the propeller test piece (18) passes through the lower movable crossbeam (12) and is connected to the fixed connecting rod (25), and the bottom end of the fixed connecting rod (25) is threadedly connected to an adjusting hand wheel (23).

3. The propeller blade fatigue life testing mechanism for testing wind tunnel test models according to claim 2, characterized in that: An aerodynamic loading limit seat (6) is installed on the upper end surface of the upper crossbeam (10), and the aerodynamic loading limit seat (6) is located below the lever (4).

4. The propeller blade fatigue life testing mechanism for testing wind tunnel test models according to claim 3, characterized in that: The upper end surface of the main frame (1) is a main frame upper plane plate (3), and a balance column (24) is provided between the main frame upper plane plate (3) and the lower end surface of the upper crossbeam (10); a scale (8) is provided on the balance column (24), and a pointer is provided on the weight suspension rod (7) for indicating the lever balance indication.

5. The propeller blade fatigue life testing mechanism for testing wind tunnel test models according to claim 4, characterized in that: An adjustable balance weight (5) is provided at the end of the lever (4).

6. The propeller blade fatigue life testing mechanism for testing a wind tunnel test model according to claim 5, characterized in that: The lower end of the weight suspension rod (7) is hung with a lifting weight via an adjustable tension spring (19).

7. The propeller blade fatigue life testing mechanism for testing a wind tunnel test model according to claim 6, characterized in that: The host frame (1) is a box-type container, and the upper end surface of the host frame (1) is a host frame upper plane plate (3). The host frame upper plane plate (3) is partially perforated, and the weight suspension rod (7) extends into the host frame (1) through the hole, and the weight is stored in the host frame (1).

8. The propeller blade fatigue life testing mechanism for testing a wind tunnel model according to claim 7, characterized in that: The main frame (1) is a square box-shaped stainless steel container.

9. The propeller blade fatigue life testing mechanism for testing a wind tunnel model according to claim 8, characterized in that: Double door panels and a door lock are arranged in front of the main frame (1).

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