CN105781904A - 30% thickness aerofoil suitable for megawatt-grade wind turbine blade - Google Patents

Abstract

The invention provides a 30% thickness aerofoil suitable for a megawatt-grade wind turbine blade. The relative thickness of the 30% thickness aerofoil is 0.30C; a tangential position which corresponds with the maximal thickness is 0.308C; the thickness of a back edge is 0.017C, wherein C is chord length of the aerofoil. The geometric coordinate expressions of the upper surface and the lower surface of the aerofoil are respectively shown in the description. The 30% thickness aerofoil is advantageous in that the 30% thickness aerofoil satisfies a requirement for the middle-segment aerofoil of a large-size wind turbine blade; lift-drag ratios in a relatively large lift coefficient on the condition of high Reynolds number (6 million) are larger than that of an NPU-WA-300 aerofoil; and furthermore the 30% thickness aerofoil has a lift characteristic which is equivalent with that of the NPU-WA-300 aerofoil.

Description

The 30% thickness aerofoil profile suitable in blade of megawatt level wind machine

Technical field

The invention belongs to vane airfoil profile design field, be specifically related to a kind of 30% thickness aerofoil profile suitable in blade of megawatt level wind machine.

Background technology

Vane design of wind turbines is a core technology of wind power generating set design, the aerofoil profile constituting blade is the basis of blade design, research and the application of this technology can design the high-performance blade with more wind-energy capture ability and low system load, have great importance for the design of major diameter wind energy conversion system.

Northwestern Polytechnical University designs NPU-WA wind mill airfoil race for MW class large scale wind power machine, that is: number of patent application is that the patent of invention of CN201110023215.1 discloses NPU-WA wind mill airfoil race, include 7 aerofoil profiles altogether, the relative thickness of 7 aerofoil profiles respectively 0.15,0.18,0.21,0.25,0.30,0.35 and 0.40, the rear edge thickness respectively 0.5%C of each aerofoil profile, 0.45%C, 0.5%C, 0.9%C, 1.7%C, 2.4%C and 3.0%C；Wherein C is the chord length of each aerofoil profile；And disclose in detail the coordinate data of every kind of aerofoil profile.Aerofoil profile disclosed in this invention, compares traditional airfoil and has higher maximum lift coefficient, and have higher design lift coefficient, bigger lift-drag ratio and better high reynolds number characteristic, and the design Reynolds number of its main wing type and outside aerofoil profile is 6.0 × 10⁶。

Applicant has carried out from 1.0 × 10 in NF-3 Low Speed Airfoil wind-tunnel⁶To 5.0 × 10⁶The wind tunnel experiment of 5 different Reynolds number, by the analysis to Wind Tunnel Data, 30% thickness aerofoil profile in NPU-WA series aerofoil sections, it is designated as NPU-WA-300, having the advantage that when high reynolds number and high design lift coefficient and have good lift-drag ratio characteristic, maximum lift-drag ratio is better than similar aerofoil profile；Twist lift-drag ratio in situation at fixing turn and be not less than similar aerofoil profile；And there is bigger maximum lift coefficient.But, it have been investigated that, the NPU-WA-300 aerofoil profile disclosed in foregoing invention patent has the disadvantage that the lifting resistance characteristic of high reynolds number condition Airfoil awaits further raising.

Summary of the invention

For the defect that prior art exists, the present invention provides a kind of 30% thickness aerofoil profile suitable in blade of megawatt level wind machine, can effectively solve the problems referred to above.

The technical solution used in the present invention is as follows:

The present invention provides a kind of 30% thickness aerofoil profile suitable in blade of megawatt level wind machine, and relative thickness is 0.30C, and the chordwise location that maximum gauge is corresponding is 0.308C, and rear edge thickness is 0.017C, and wherein C is aerofoil profile chord length；The geometric coordinate expression formula of this aerofoil profile upper and lower surface is respectively as follows:

$\frac{y_{up}}{C}=0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}(1-\frac{x}{C})\·\underset{i=0}{\overset{4}{\Σ}}(A_{{\mathrm{up}}_i}\·\frac{4!}{i!(4-i)!}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{4-i})$

$\frac{y_{low}}{C}=-0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}(1-\frac{x}{C})\·\underset{i=0}{\overset{4}{\Σ}}(A_{{\mathrm{low}}_i}\·\frac{4!}{i!(4-i)!}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{4-i})$

Wherein, y_upRepresent the upper surface vertical coordinate of aerofoil profile；y_lowRepresent the lower surface vertical coordinate of aerofoil profile；A_upRepresent the expression formula coefficient of aerofoil profile upper surface geometric coordinate；A_lowRepresent the expression formula coefficient of aerofoil profile lower surface geometric coordinate；X represents the surface abscissa of aerofoil profile；

A_upAnd A_lowValue in Table 1:

The expression formula coefficient of table 1 aerofoil profile upper and lower surface geometric coordinate

The 30% thickness aerofoil profile suitable in blade of megawatt level wind machine provided by the invention has the advantage that

The present invention provides a kind of 30% thickness aerofoil profile suitable in blade of megawatt level wind machine, it is designated as NPU-WA2-300, have the advantage that and meet large scale wind power machine blade stage casing aerofoil profile demand, under high reynolds number (6,000,000) condition, within the scope of bigger lift coefficient, lift-drag ratio is above NPU-WA-300 aerofoil profile, and has the lift efficiency suitable with NPU-WA-300 aerofoil profile.

Accompanying drawing explanation

Fig. 1 is the geometric shape figure of NPU-WA2-300 aerofoil profile provided by the invention；

Fig. 2 is NPU-WA2-300 aerofoil profile and the lift efficiency comparison diagram of NPU-WA-300 aerofoil profile (MSES, Re=6 × 10⁶, freely turn and twist)；

Fig. 3 is NPU-WA2-300 aerofoil profile and the lift-drag ratio Property comparison figure of NPU-WA-300 aerofoil profile (MSES, Re=6 × 10⁶, freely turn and twist)；

Wherein, 1 NPU-WA2-300 aerofoil profile is represented；2 represent NPU-WA-300 aerofoil profile.

Detailed description of the invention

In order to make technical problem solved by the invention, technical scheme and beneficial effect clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein is only in order to explain the present invention, is not intended to limit the present invention.

The present invention provides a kind of 30% thickness aerofoil profile suitable in blade of megawatt level wind machine, it is designated as NPU-WA2-300, as shown in Figure 1, geometric shape figure for NPU-WA2-300 aerofoil profile provided by the invention, compared with the published NPU-WA-300 aerofoil profile of prior art, NPU-WA2-300 aerofoil profile provided by the invention maintains suitable lift efficiency, and maximum lift-drag ratio and high lift-drag ratio condition range all increase to some extent.

Concrete, NPU-WA2-300 aerofoil profile provided by the invention, relative thickness is 0.30C, and the chordwise location that maximum gauge is corresponding is 0.308C, and rear edge thickness is 0.017C, and wherein C is aerofoil profile chord length；The geometric coordinate expression formula of this aerofoil profile upper and lower surface is respectively as follows:

$\frac{y_{up}}{C}=0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}(1-\frac{x}{C})\·\underset{i=0}{\overset{4}{\Σ}}(A_{{\mathrm{up}}_i}\·\frac{4!}{i!(4-i)!}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{4-i})$

$\frac{y_{low}}{C}=-0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}(1-\frac{x}{C})\·\underset{i=0}{\overset{4}{\Σ}}(A_{{\mathrm{low}}_i}\·\frac{4!}{i!(4-i)!}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{4-i})$

Wherein, y_upRepresent the upper surface vertical coordinate of aerofoil profile；y_lowRepresent the lower surface vertical coordinate of aerofoil profile；A_upRepresent the expression formula coefficient of aerofoil profile upper surface geometric coordinate；A_lowRepresent the expression formula coefficient of aerofoil profile lower surface geometric coordinate；X represents the surface abscissa of aerofoil profile；

A_upAnd A_lowValue in Table 1:

The expression formula coefficient of table 1 aerofoil profile upper and lower surface geometric coordinate

Above-mentioned aerofoil profile disclosed in this invention, key point is: meet large scale wind power machine blade stage casing aerofoil profile demand, under high reynolds number (6,000,000) condition, within the scope of bigger lift coefficient, lift-drag ratio is above NPU-WA-300 aerofoil profile, and has the lift efficiency suitable with NPU-WA-300 aerofoil profile.

NPU-WA2-300 aerofoil profile has higher design lift, bigger lift-drag ratio and better high reynolds number characteristic.Because the lift acted on blade section is equal to the product of lift coefficient, chord length and incoming flow dynamic pressure, therefore, higher design lift coefficient can allow to shorten the chord length of blade, thus reducing leaf weight, or allows when identical chord length to work under less wind speed；Bigger lift-drag ratio can improve power coefficient, and performance higher under high reynolds number can meet the design requirement of large scale wind power machine blade.

Below by way of experiment effect example, the advantage of NPU-WA2-300 aerofoil profile provided by the invention is verified:

Inventor uses the aeroperformance of aerofoil profile aerodynamic analysis software MSES comparing calculation NPU-WA2-300 aerofoil profile of the present invention and traditional NPU-WA-300 aerofoil profile, calculates state: Mach 2 ship 0.2, Reynolds number is 6 × 10⁶.Result of calculation is respectively as shown in Figures 2 and 3.The performance comparison of NPU-WA2-300 and NPU-WA-300 aerofoil profile is in Table 2:

The performance comparison of table 2NPU-WA2-300 aerofoil profile and NPU-WA-300 aerofoil profile

From Fig. 2 and Biao 2 it will be seen that the lift efficiency of NPU-WA2-300 aerofoil profile keeps quite with NPU-WA-300 aerofoil profile, maximum lift coefficient is slightly below NPU-WA-300 aerofoil profile.From Fig. 3 and Biao 2 it will be seen that the maximum lift-drag ratio of NPU-WA2-300 aerofoil profile is higher than NPU-WA-300 aerofoil profile, and the lift-drag ratio in very wide lift tange is above NPU-WA-300 aerofoil profile.

The above is only the preferred embodiment of the present invention; it should be pointed out that, for those skilled in the art, under the premise without departing from the principles of the invention; can also making some improvements and modifications, these improvements and modifications also should look protection scope of the present invention.

Claims (1)

1. being applicable to a 30% thickness aerofoil profile of blade of megawatt level wind machine, relative thickness is 0.30C, and the chordwise location that maximum gauge is corresponding is 0.308C, and rear edge thickness is 0.017C, and wherein C is aerofoil profile chord length；It is characterized in that, the geometric coordinate expression formula of this aerofoil profile upper and lower surface is respectively as follows:

$\frac{y_{up}}{C}=0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}\left(1-\frac{x}{C}\right)\·\underset{i=0}{\overset{4}{\Σ}}(A_{{\mathrm{up}}_i}\·\frac{4!}{i!(4-i)1}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{4-i})$

$\frac{y_{low}}{C}=-0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}(1-\frac{x}{C})\·\underset{i=0}{\overset{4}{\Σ}}(A_{{\mathrm{low}}_i}\·\frac{4!}{i!(4-i)!}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{4-i})$

Wherein, y_upRepresent the upper surface vertical coordinate of aerofoil profile；y_lowRepresent the lower surface vertical coordinate of aerofoil profile；A_upRepresent the expression formula coefficient of aerofoil profile upper surface geometric coordinate；A_lowRepresent the expression formula coefficient of aerofoil profile lower surface geometric coordinate；X represents the surface abscissa of aerofoil profile；

A_upAnd A_lowValue in Table 1:

The expression formula coefficient of table 1 aerofoil profile upper and lower surface geometric coordinate