CN1963192A

CN1963192A - Heavy-camber wind mill airfoil

Info

Publication number: CN1963192A
Application number: CNA2005100476682A
Authority: CN
Inventors: 申振华
Original assignee: Shenyang Institute of Aeronautical Engineering
Current assignee: Shenyang Institute of Aeronautical Engineering
Priority date: 2005-11-09
Filing date: 2005-11-09
Publication date: 2007-05-16
Anticipated expiration: 2025-11-09
Also published as: CN100443720C

Abstract

The heavy camber wind mill aerofoil keeps the shape of the suction surface of the traditional paddle, substantially changes the pressure surface and the backside, and greatly improves the bending of the aerofoil, overcoming the shortcomings of small bending of the aerofoil and low work-done capacity of the traditional horizontal aerogenerator. Under the same conditions, it greatly improves the utilization coefficient of the wind and reduces the generating cost.

Description

Heavy-camber wind mill airfoil

Technical field: the present invention relates to a kind of heavy-camber wind mill airfoil, exactly is a kind of aerofoil profile of horizontal-shaft wind turbine blade, belongs to wind energy conversion system design, manufacturing and application.

Background technique: the aerofoil profile of present wind machine oar leaf has many kinds, and what have continues to use traditional air-foil, as NACA4412, and 4415,4418,23012,23015 etc.; G  ttingen623,624 etc., laminar flow airfoil such as FX60.126,61.140 etc.; Designed special airfoil at wind energy conversion system again afterwards, as FFA-W3 series aerofoil profile etc.; But no matter any aerofoil profile, its acting ability all is subjected to the restriction of camber.

No matter modern horizontal-shaft wind turbine on profile still is choosing of blade aerofoil profile, has all followed the custom of properller, but has gone over, and propeller cavitation originally is " driven machine ", belongs to " gas compressor " class; Wind energy conversion system then is prime mover, belongs to " turbine " class, also is wind-force " turbine ".So, it why originally is the aerofoil profile that the wind energy conversion system of turbine but will be selected the gas compressor class for use? in aeroengine, what gas compressor the one-level turbine can drive, that is to say, the acting energy force rate single-stage compressor of single stage turbine is much bigger, its difference just is the camber difference of blade, the camber ratio gas compressor of turbine blade much bigger.But, on wind energy conversion system, the heavy camber aerofoil profile of indiscriminately imitating turbine simply also is not all right, because the operating conditions of wind energy conversion system is different with the turbine on the motor after all, they mainly be the restriction that latter's air-flow is subjected to casing, and blade quantity is a lot, the denseness of blade (also being solidity) is very big, air-flow between blade mobile being restricted and flow separation be difficult for to take place, particularly at the suction surface of blade; Therefore yet wind energy conversion system then has only 2-3 blade, and " denseness " far from will produce flow separation and influence the performance of wind energy conversion system when the angle of attack is big at suction surface.In order to improve the acting ability of blade, the someone proposes to install additional in traditional aerofoil profile trailing edge pressure side one side the scheme of Gurney wing flap, and this has increased the camber of aerofoil profile, as long as the height of wing flap is suitable, then can reach higher ratio of lift coefficient to drag coefficient; But be not all aerofoil profiles to take this measure all be effectively, and wing flap has significantly increased flow resistance.The present invention has then taked another effective measures to improve the acting ability of blade.

Summary of the invention: the shape that the objective of the invention is to revise traditional aerofoil profile, make " turbine " character true colours of as far as possible going back wind turbine, improve the ability that wind energy conversion system absorbs wind energy, the ability of promptly doing work, thereby kept the gas compressor character of traditional aerofoil profile suction surface, preventing the airflow breakaway when the big angle of attack, thereby kept the good aeroperformance of original aerofoil profile; And, then embody the turbine character of wind energy conversion system at pressure side, and strengthen the camber of aerofoil profile as far as possible, increasing substantially its acting ability, thereby improve the power coefficient of wind energy conversion system.

Advantage of the present invention is: the power coefficient of wind energy conversion system improves greatly, and cost of electricity-generating is reduced, its weight saving simultaneously, and this has further reduced its cost of production again.

Description of drawings

Fig. 1 is a structural representation of the present invention.

Fig. 2 is the local enlarged diagram of Fig. 1.

Fig. 3 is the comparison schematic representation of traditional aerofoil profile and aerofoil profile of the present invention.

Fig. 4 is the power raising rate data and curves that the wind-tunnel comparative experiment of aerofoil profile and traditional aerofoil profile according to the present invention is drawn.

Embodiment

With reference to Fig. 1,2, aerofoil profile of the present invention is made up of leading edge 23, blunt trailing edge 27 (promptly going up the line of trailing edge point 24 and following trailing edge point 25), suction surface 21 (from leading edge 23 to last trailing edge point 24), pressure side 22 (from leading edge 23 to descending trailing edge point 25), its string of a musical instrument length is called for short chord length, refers to the distance from leading edge 23 to 24 of last trailing edge points here.Mean camber line 28 (being the line at the incircle center of aerofoil profile each point), the maximum camber of aerofoil profile is b.Air-flow flows to trailing edge 27 from leading edge 23 shuntings through suction surface 21 and pressure side 22.At pressure side, from putting 26, pressure side 22 is earlier to evagination, connect radius R 1 greater than 30% chord length, then concave glossily, connect radius R 2 greater than 55% chord length, and smooth transition is to the following trailing edge point 25 of trailing edge 27, to guarantee in the work angle of attack scope of the aerofoil profile segregation phenomenon of air-flow from pressure side 22 not taking place; Point 26 is the 5%-20% of its chord length apart from leading edge 23 along chordwise distance, to keep some premium properties of traditional aerofoil profile, for example to the adaptability of angle of attack variation and in the superperformance that has under the foreign material pollution condition; R1 will make the maximum ga(u)ge of aerofoil profile be not more than the maximum ga(u)ge of corresponding traditional aerofoil profile with the connection of R2; The thickness of blunt trailing edge 27 is the chord length of 0-2%, and obviously, when the thickness of trailing edge 27 was 0, blunt trailing edge had then become common sharp trailing edge.Aerofoil profile maximum camber of the present invention is b, and the maximum camber value is between the 4%-10% chord length.Fig. 2 is the local enlarged diagram of the trailing edge of Fig. 1.

With reference to Fig. 3, with aerofoil profile of the present invention and the overlapping placement of traditional aerofoil profile, dotted line is the mean camber line 18 of traditional aerofoil profile among the figure, and obviously the maximum camber b of aerofoil profile of the present invention has increased greatly than the maximum camber a of traditional aerofoil profile, and also the quality than traditional aerofoil profile is light for the quality of aerofoil profile of the present invention simultaneously.

With reference to Fig. 4, the power of drawing for the wind energy conversion system wind-tunnel contrast experiment data of aerofoil profile and traditional aerofoil profile according to the present invention improves rate curve.As seen, the power of the wind energy conversion system of aerofoil profile of the present invention is housed, or power coefficient increases greatly.

Propose although The present invention be directed to wind energy conversion system, its design philosophy is equally applicable to the blade and the low speed aerofoil profile of all gas compressor classes, as rotor of axial flow compressor, axial-flow blower, propeller cavitation and helicopter etc.

Claims

1, a kind of heavy-camber wind mill airfoil, form by leading edge (23), trailing edge (27), suction surface (21) and pressure side (22), suction surface (21) is the profile of gas compressor class blade profile, it is characterized in that: the traditional gas compressor blade profile camber of the camber ratio of described pressure side (22) increases, and the maximum camber that makes aerofoil profile is between 4%-10% aerofoil profile chord length.

2, heavy-camber wind mill airfoil according to claim 1 is characterized in that: the pressure side (22) after 5%-20% aerofoil profile chord length connects radius R 1 greater than 30% aerofoil profile chord length earlier to evagination; Follow smooth concaving, connect radius R 2 greater than 55% aerofoil profile chord length, and smooth transition is to trailing edge (27).

3, heavy-camber wind mill airfoil according to claim 1 is characterized in that: aerofoil profile can have blunt trailing edge or sharp trailing edge, and edge thickness is a 0-2% aerofoil profile chord length thereafter.