Method for adjusting pitch angle of wind turbine blade wind tunnel flutter test model

Abstract

The invention discloses a method for adjusting a pitch angle of a wind turbine blade wind tunnel flutter test model, and belongs to the technical field of wind tunnel flutter tests. According to the method, the pitch angle is adjusted according to working conditions by taking a root joint scale line at the root of a blade as a vernier and taking a hub scale line on an upper hub as a dividing ruler; in a wind tunnel test of a blade scaling model, the target pitch angle can be quickly positioned, and meanwhile, the required pitch angle can be conveniently adjusted. And the structural form is simple to manufacture and convenient to maintain. The method solves the problem of the installation precision of the pitch angle of the model when the large-scale wind power blade scaling model is in the wind tunnel test, and is safe, reliable, simple and accurate.

Description

Technical Field

[0001] The invention relates to a method for adjusting a pitch angle of a wind tunnel flutter test model of a wind turbine blade, and belongs to the technical field of wind tunnel flutter tests. Background Art

[0002] Flutter research is an indispensable part of the design process of large wind turbine blades today, and wind tunnel flutter testing is an important part of flutter research. Since flutter has many forms, the mathematical and physical relationships that need to be considered when calculating the critical flutter speed are very complex. Therefore, in the design process of large wind turbine blades, the wind tunnel flutter test can be used to verify whether the wind turbine blades will flutter. The adjustment of the model's pitch angle in the wind tunnel flutter test needs to be accurate, simple, and reliable. The existing model pitch angle control schemes are either not accurate enough or too complex in structure. People are eager to find a simple, reliable, and efficient pitch angle control scheme for wind tunnel flutter tests of wind turbine blades. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a method for adjusting the pitch angle of a wind turbine blade wind tunnel flutter test model, which can achieve the purpose of simple structure during manufacturing, convenient operation during installation, and accurate and reliable during use.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] A method for adjusting the pitch angle of a wind turbine blade wind tunnel flutter test model comprises the following steps:

[0006] S1. The blade root of the scaled model of the wind turbine blade is a cylindrical root joint pillow block, the hub includes an upper hub and a lower hub, and a spline is provided at the mating position between the hub and the rotating shaft;

[0007] S2. At the joint between the root joint pillow block and the hub, a root joint scale line is set on the root of the blade; a hub scale line is set on the upper hub;

[0008] S3. Place the blade root between the upper hub and the lower hub, and bolt it into the hub bolt hole to lock the hub;

[0009] S4. Before the test, use the root joint scale line at the root of the blade as the vernier and the hub scale line on the upper hub as the scale to adjust the pitch angle according to the working conditions;

[0010] S5. After the blade root is adjusted to the appropriate pitch angle, the bolts are passed through the bolt holes of the joint pillow block and applied to the root joint pillow block to lock it;

[0011] S6. Start the wind tunnel, wait for the airflow to stabilize, and then measure the blade operating parameters;

[0012] S7. After the measurement is completed, repeat steps S4 and S5, change the working conditions and measure again.

[0013] Furthermore, the root joint scale line set on the blade root is 1.9 degrees, and the hub scale line set on the upper hub is 2 degrees, with an accuracy of 0.1 degrees.

[0014] The beneficial effects of the present invention are as follows: the method uses the root joint scale line at the root of the blade as a vernier, and the hub scale line on the upper hub as a scale to adjust the pitch angle according to the working conditions; in the wind tunnel test of the blade scale model, the target pitch angle can be quickly located, and the required pitch angle can be conveniently adjusted. The structural form is also simple to make and easy to maintain; the positioning accuracy can also be guaranteed to reach 0.1 degrees (the accuracy can be improved after the scale interval is adjusted); this solution solves the problem of the pitch angle installation accuracy of the model during the wind tunnel test of the large wind turbine blade scale model. The design method does not require additional new processes and new materials, and is convenient for the design, production, inspection and use of the model. The method is safe, reliable, simple and accurate.

[0015] The pitch angle control described in this scheme is applied in the wind tunnel test of the blade scale model. During the wind tunnel test of the wind turbine blade scale model, it is necessary to adjust different pitch angles to achieve the purpose of reaching different rotational speeds of the blade under the same wind speed. Therefore, in order to accurately position different pitch angles while ensuring a simple structure and easy operation; this scheme designs the root joint of the blade into a cylindrical pillow block form, which is then connected to the hub through a set screw, and the hub is connected to the rotating shaft through a spline; at the same time, scale lines are engraved on the cylindrical joint at the root of the blade at a position corresponding to the hub. During the test, the pitch angle can be adjusted according to the required number. At the same time, the cylindrical design of the joint makes it convenient to adjust the pitch angle during the test. The engraved lines are processed according to the principle of a vernier caliper, and the scale lines are processed on the joint and the hub according to the "vernier" and "divider", so that the accuracy of adjusting the pitch angle is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the blade root.

[0017] Figure 2 It is a schematic diagram of the structure of the wheel hub.

[0018] Figure 3 It is an assembly drawing of the present invention.

[0019] In the figure: 1. Blade root, 2. Root joint pillow block, 3. Root joint scale line, 4. Upper hub, 5. Lower hub, 6. Hub scale line, 7. Spline, 8. Hub bolt hole, 9. Joint pillow block bolt hole. DETAILED DESCRIPTION

[0020] The present invention is described below with reference to the accompanying drawings and specific embodiments:

[0021] Figure 1-3 The present invention shows a composition diagram, a method for adjusting the pitch angle of a wind turbine blade wind tunnel flutter test model, comprising the following steps:

[0022] S1. The blade root 1 of the scaled model of the wind turbine blade is a cylindrical root joint pillow block 2, the hub includes an upper hub 4 and a lower hub 5, and a spline 7 is arranged at the joint between the hub and the rotating shaft; the hub is designed to be connected in two parts, the upper and lower parts, by bolts.

[0023] S2. At the matching point between the root joint pillow block 2 and the hub, a root joint scale line 3 is set on the blade root 1; a hub scale line 6 is set on the upper hub 4; the root joint scale line 3 set on the blade root 1 is 1.9 degrees, and the hub scale line 6 set on the upper hub 4 is 2 degrees, with an accuracy of 0.1 degrees.

[0024] S3. Place the blade root 1 between the upper hub 4 and the lower hub 5, and bolt into the hub bolt hole 8 to lock the hub; the blade root joint and the hub are fixed with set screws.

[0025] S4. Before the test, use the root joint scale line 3 of the blade root 1 as a cursor and the hub scale line 6 on the upper hub 4 as a scale to adjust the pitch angle according to the working conditions;

[0026] S5. After the blade root 1 is adjusted to a suitable pitch angle, a bolt is passed through the joint pillow block bolt hole 9 and then acts on the root joint pillow block 2 to lock it;

[0027] S6. Start the wind tunnel, wait for the airflow to stabilize, and then measure the blade operating parameters;

[0028] S7. After the measurement is completed, repeat steps S4 and S5, change the working conditions and measure again.

[0029] Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for adjusting the pitch angle of a wind turbine blade wind tunnel flutter test model, characterized in that: The following steps are involved: S1. The blade root (1) of the scaled model of the wind turbine blade is a cylindrical root joint pillow block (2), the hub includes an upper hub (4) and a lower hub (5), and a spline (7) is provided at the mating position between the hub and the rotating shaft; S2. At the mating point between the root joint pillow block (2) and the hub, a root joint scale line (3) is provided on the blade root (1); a hub scale line (6) is provided on the upper hub (4); S3. The blade root (1) is placed between the upper hub (4) and the lower hub (5), and the hub is locked by bolting the bolts into the hub bolt holes (8); S4. Before the test, use the root joint scale line (3) of the blade root (1) as a vernier and the hub scale line (6) on the upper hub (4) as a scale to adjust the pitch angle according to the working conditions; S5. After the blade root (1) is adjusted to a suitable pitch angle, a bolt is passed through the bolt hole (9) of the joint pillow block and then applied to the root joint pillow block (2) to lock it; S6. Start the wind tunnel, wait for the airflow to stabilize, and then measure the blade operating parameters; S7. After the measurement is completed, repeat steps S4 and S5, change the working conditions and measure again.

2. The method for adjusting the pitch angle of a wind turbine blade wind tunnel flutter test model according to claim 1, characterized in that: The root joint scale line (3) arranged on the blade root (1) is 1.9 degrees, and the hub scale line (6) arranged on the upper hub (4) is 2 degrees, with an accuracy of 0.1 degrees.

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