CN202370744U - Wind turbine blade airfoil - Google Patents

Abstract

The utility model relates to a wind turbine blade airfoil used for horizontal axis wind turbine blades. It uses reverse engineering to obtain the coordinate values of the upper and lower surfaces of the barn swallow wing airfoil, and compares it with the standard airfoil through wind tunnel experiments. The position of the maximum thickness (t) of the imitation barn swallow airfoil occupies 27.3% to 36.4% of the chord length; the position of the maximum camber (f) accounts for 45.5% to 54.5% of the chord length; The airfoil is reduced by about 1 time to reduce the windward area of the airfoil and reduce the pressure difference resistance; the maximum thickness (t) is reduced by about 1.2 times compared with the standard airfoil, which can prevent the airflow on the airfoil from separating prematurely. Cause lift loss; the maximum camber (f) is about twice that of the standard airfoil, which increases the flow velocity difference between the upper and lower surfaces of the bionic airfoil, thereby increasing the pressure difference between the upper and lower surfaces and increasing the lift. The utility model has better lift force and lift-to-drag ratio, and can improve the overall aerodynamic characteristics.

Description

A wind turbine blade airfoil

Technical field:

The utility model relates to an airfoil of a blade of a wind power generator, in particular to an airfoil of a blade of a horizontal axis wind power generator. the

Background technique:

Wind power is one of the most promising new energy power generation technologies in the world today, and its large-scale research and development and utilization have become the focus of new energy development in the world in the 21st century. my country is not only a big producer and exporter of wind power equipment, but also a big consumer. The market potential for household small wind power equipment is huge. the

At present, there are mainly two types of wind turbines: horizontal axis and vertical axis. The horizontal axis wind turbine is widely used in the world. This type of wind turbine is suitable for large-scale wind farms. The blade of a wind turbine is the core part of a wind turbine to capture wind energy, and the airfoil that constitutes the aerodynamic shape of the blade determines the performance of the blade and is the key to the design of the blade. It directly determines the efficiency of wind energy conversion. Therefore, research on high-performance airfoils Type has its inevitability. the

As early as the middle of the 20th century, foreign countries conducted special research on wind turbine airfoils. The Danish National Laboratory proposed three special airfoil families for wind turbines, RisФ-A1, RisФ-P, and RisФ-B1; the Swedish Aeronautical Research Institute designed the FFA-W1, WZ, W3 special airfoil families for wind turbines; the Delft University of the Netherlands developed The DU airfoil family. These special airfoils for wind turbines have relatively gentle stall characteristics, low leading edge sensitivity, and low noise, but their efficiency in converting wind energy still has a lot of room for development compared with the Betz theory, that is, the lift of the airfoil And the lift-to-drag ratio needs to be further improved, so as to increase the utilization rate of wind energy and reduce energy loss. the

In today's highly developed society, bionics has been recognized by more and more scholars and experts as an independent discipline, and in the development and changes of hundreds of millions of years, organisms have the nature of adapting to nature, and have their own unique characteristics. research value. the

In nature, birds and insects are in direct contact with the air, and the wings of birds are also formed by a series of airfoils arranged horizontally, which is most similar to the working conditions of wind turbines. The utility model takes barn swallow as the research object, applies its wing airfoil to the wind turbine, and intends to solve the problem of low utilization rate of wind energy. The barn swallow is the most common summer migratory bird and one of the fastest flying birds in the world. Its long and narrow wings are suitable for fast flight and long-distance migration and have strong flexibility. the

Invention content:

The utility model relates to a wind turbine blade airfoil, aiming at the situation that the lift and lift-drag ratio of the special airfoil for wind generators are generally not high, so that the lift and lift-drag ratio can be achieved under different Reynolds numbers and different attack angles. It can be greatly improved. Applying the imitation swallow airfoil to the wind turbine can solve the problems of low wind energy utilization rate and large loss of the horizontal axis wind turbine, and save energy costs. the

The above-mentioned purpose of the utility model is achieved in that, it is described as follows in conjunction with accompanying drawing:

A wind turbine blade airfoil is composed of chord length, thickness, leading edge radius and camber, when the chord length c is 1, the maximum thickness t ranges from 0.0573 to 0.0617, and the leading edge radius r is The value range is 0.00522～0.00679, the value range of the camber f is 0.0708～0.0771, and the position of the maximum thickness t occupies 27.3%～36.4% of the value range of the chord length c, and the position of the maximum camber occupies all 45.5% to 54.5% of the range of the chord length c. the

The radius of the leading edge of the airfoil imitating the house swallow of the utility model is about 1 times smaller than that of the standard airfoil NACA4412, which will reduce the windward area of the airfoil so as to reduce the pressure difference resistance; the maximum thickness is reduced by 1.1 compared with the standard airfoil It can prevent the airflow on the airfoil from separating prematurely when it flows through the upper surface, resulting in loss of lift; the maximum camber of the imitation swallow airfoil is obviously higher than that of the standard airfoil, which is about 2 times that of the standard airfoil. This increases the flow velocity difference between the upper and lower surfaces of the bionic airfoil, thereby increasing the pressure difference between the upper and lower surfaces of the airfoil, thus increasing the lift. the

The utility model has the following advantages: the airfoil of the utility model can obtain excellent aerodynamic characteristics without changing its own shape and surface structure: the range of the angle of attack during the experiment is -10°～40°, and the Reynolds number is 60000, 80000, the measured lift coefficient of the imitation swallow airfoil is 36.25% and 26.9% higher than the standard airfoil, and the lift-to-drag ratio is 28.9% and 38.5% higher than the standard airfoil; the experimental data of the utility model is obtained through the actual wind tunnel Compared with the data obtained from the previous simulation analysis, the experimental results are more convincing. the

Description of drawings:

Figure 1 is a schematic diagram of a bionic airfoil. the

Fig. 2 is a partial enlarged view of Fig. 1A. the

Figure 3 is a comparison curve of the lift coefficient of the imitation swallow airfoil and the standard airfoil NACA4412 at an angle of attack of -10° to 40° and a Reynolds number of 60,000 and 80,000 under the actual blowing conditions of the wind tunnel experiment. the

Figure 4 is a comparison curve of the lift-to-drag ratio of the imitation swallow airfoil and the standard airfoil NACA4412 at an angle of attack of -10° to 40° and a Reynolds number of 60,000 and 80,000 in the case of actual blowing in the wind tunnel experiment. the

In the figure: r-leading edge radius t-maximum thickness f-camber c-chord length d-camber line B-upper airfoil C-lower airfoil

Detailed ways:

Referring to Fig. 1, the chord length c of the swallow-like airfoil is the unit length 1, the leading edge radius r is 0.00679, the maximum thickness t is 0.0573, the camber f is 0.0771, and the maximum thickness position is: x _t /c = 27.3%, that is, the maximum The position of the thickness t is 27.3% of the chord length c; the position of the camber is: x _f /c=54.5%, that is, the position of the camber f is 54.5% of the chord length, where x _t is the position of the maximum thickness in the airfoil x _f is the abscissa value of the position of the camber on the airfoil. The radius of the leading edge is about 1 times smaller than that of the standard airfoil NACA4412, which will reduce the windward area of the airfoil and reduce the pressure drop resistance; the maximum thickness is about 1.1 times smaller than that of the standard airfoil, which can prevent airfoils from When the airflow flows through the upper surface, it will be separated prematurely, resulting in loss of lift; the maximum camber of the imitation swallow airfoil is obviously higher than that of the standard airfoil, which is about twice that of the standard airfoil, which makes the upper and lower sides of the imitation swallow airfoil The flow velocity difference on the surface of the lower airfoil increases, so the pressure difference between the upper and lower surfaces of the airfoil increases, so the lift force increases.

Imitating the house swallow airfoil 1, the coordinates corresponding to the upper and lower airfoils satisfy the following table: 

Table 1

Imitating the house swallow airfoil 2, the coordinates corresponding to the upper and lower airfoils satisfy the following table: 

Table 2

Figure 3 is a graph showing the variation of the lift coefficient with the angle of attack between the airfoil of the imitation swallow and the standard airfoil, which is obtained through actual blowing tests in the wind tunnel laboratory. It can be seen that the lift coefficients of the imitation swallow airfoils are all greater than the standard airfoils. And with the increase of the angle of attack, the lift coefficient shows an increasing trend. When the angle of attack increases to about 40°, the lift coefficient begins to have a downward trend. It can be seen from the figure that when the Reynolds number is 60000 and the angle of attack is 38°, the lift coefficient of the imitation swallow airfoil reaches the maximum, which is 0.3488; while the standard airfoil NACA4412 has a maximum lift coefficient of 0.256 when the Reynolds number is 60000, Compared with the standard airfoil NANCA4412, the lift coefficient of the imitation house swallow airfoil can be increased by 36.25%. When the Reynolds numbers are 60000 and 80000 respectively, the lift coefficient of the imitation swallow airfoil is 36.25% and 26.9% higher than that of the standard airfoil. the

Figure 4 is a graph of the lift-to-drag ratio of the imitation swallow airfoil and the standard airfoil at different Reynolds numbers and different angles of attack. When the Reynolds number is 80000 and the angle of attack is 4°, the maximum lift-to-drag ratio of the imitation swallow airfoil is 6.5, which is 30% higher than the maximum lift-to-drag ratio of the standard airfoil. When the Reynolds numbers are 60000 and 80000 respectively, the lift-to-drag ratio of the imitation swallow airfoil is 28.9% and 38.5% higher than that of the standard airfoil. the

In summary, it can be seen that when the angle of attack is -10°～40°, and the Reynolds numbers are 60000 and 80000 respectively, the imitation swallow airfoil has better lift and lift-to-drag ratio than the standard airfoil NACA4412, and it is applied to the horizontal axis wind turbine. It can better improve the utilization rate of wind energy and reduce energy loss. the

Claims (3)

1. pneumatic equipment blades made aerofoil profile; Form by chord length, thickness, leading-edge radius and camber; It is characterized in that said chord length (c) is at 1 o'clock, the span of maximum ga(u)ge (t) is 0.0573～0.0617; The span of said leading-edge radius (r) is 0.00522～0.00679; The span of said camber (f) is 0.0708～0.0771, and the position at maximum ga(u)ge (t) place account for chord length (c) span 27.3%～36.4%, the position at maximum camber place accounts for 45.5%～54.5% of said chord length (c) scope.

2. a kind of pneumatic equipment blades made aerofoil profile according to claim 1 is characterized in that, the pairing coordinate figure of the upper and lower aerofoil of said aerofoil profile satisfies:

3. a kind of pneumatic equipment blades made aerofoil profile according to claim 1 is characterized in that, the pairing coordinate figure of the upper and lower aerofoil of said aerofoil profile satisfies:

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