CN2900356Y

CN2900356Y - Blunt tail edge wing

Info

Publication number: CN2900356Y
Application number: CN 200620090628
Authority: CN
Inventors: 申振华
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-04-29
Filing date: 2006-04-29
Publication date: 2007-05-16
Anticipated expiration: 2016-04-29

Abstract

A blunt stern aerofoil is provided, which maintains the suction surface shape of traditional tipped stern aerofoil, and increases the stern thickness of an aerofoil to 0.5 percent to 3.0 percent . The utility model starts the smooth connection with the blunt stern from a point on the traditional tipped stern aerofoil to form a new press surface of blunt stern aerofoil. Under the same condition, the product can make the aerodynamic performance of the aerofoil greatly enhanced. The utility model has the advantages that: the lift coefficient and lift drag ratio of the aerofoil are lifted obviously, and its stalling angle is postponed; since the new blunt stern aerofoil increases the thickness of the aerofoil at the stern area and modification part, the utility model increases the intensity and rigidity of aerofoil or propeller.

Description

Aerofoil with blunt tail edge

Technical field: the utility model relates to a kind of aerofoil with blunt tail edge, exactly belongs to Airfoil Design, manufacturing and application.

Background technology: present aerofoil profile, for example NACA series, brother's Dettingen (G  ttingen) series etc. all are fine stern edge aerofoil profiles, they all have goodish aeroperformance, especially for subsonic velocity or low speed aerofoil profile.This situation has been broken in the appearance of Ge Ni (Gurney) wing flap, and it has produced significant effects to airfoil performance, has obtained some good results under certain condition.So-called gurney flap is promptly opened up to the tablet that installs a suitable height vertical with its string of a musical instrument additional along wing or blade at the aerofoil profile trailing edge.Studies show that: gurney flap has changed the distribution of pressure on aerofoil profile suction surface and the acting face effectively, increase effective camber of aerofoil profile, thereby increased the circular rector of fluid winding flow aerofoil profile, obviously improved the lift coefficient of aerofoil profile, and highly suitably the time, can make its liter (power) resistance (power) than improving a lot.But, gurney flap with aerofoil profile be connected and structural strength on also can bring new problem.In fact, gurney flap has obviously hindered the air current flow on the acting face, and therefore when lift increased, its resistance also had sizable increase.In order to remedy this defective of gurney flap, the utility model is transformed into fine stern edge aerofoil profile the aerofoil with blunt tail edge of certain trailing edge thickness, subsonic velocity or low speed aerofoil profile aeroperformance are greatly improved, and to stride, supersonic profile also can apply and improve its performance.Have U.S. Pat 4858852 to propose a kind of " Divergent trailing-edge airfoil " before this, still the trailing edge of this aerofoil profile can only be dispersed, and only is applicable to transonic Airfoil.

Summary of the invention: the purpose of this utility model is to adopt the method for the simplest and easy enforcement to improve traditional fine stern edge airfoil aerodynamic performances, and needn't carry out complexity and expensive Airfoil Design process.Suction surface to traditional aerofoil profile remains unchanged, to keep the good aeroperformance of original aerofoil profile, and the acting face trailing edge that will treat improved fine stern edge aerofoil profile (being the aerofoil profile prototype) adds " gurney flap " of suitable height (0.5%-3.0% aerofoil profile chord length), (60%-99% aerofoil profile chord length) beginning is connected with the free edge of wing flap with smooth curve from certain chord length position with acting face again, thereby constitute new aerofoil with blunt tail edge, the trailing edge angle of this aerofoil profile can be that bear or positive, (75 ° to+60 °) promptly disperse or the convergence.

The utility model has the advantages that: the lift coefficient and the 1ift-drag ratio of aerofoil profile obviously improve, and the stalling incidence of aerofoil profile is postponed greatly; Because aerofoil with blunt tail edge of the present utility model has strengthened the trailing edge zone and revised the profile thickness at position, thereby the intensity and the rigidity of wing or blade have been increased; Implement simply, cost is low.

Description of drawings

Fig. 1 is that traditional fine stern edge aerofoil profile and aerofoil with blunt tail edge of the present utility model compare scheme drawing.

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

Fig. 3 is the lift coefficient comparison curve of traditional fine stern edge aerofoil profile and the utility model aerofoil with blunt tail edge.

Fig. 4 is aerofoil with blunt tail edge of the present utility model improves percentum with respect to the 1ift-drag ratio of traditional fine stern edge aerofoil profile a curve.

The specific embodiment

With reference to Fig. 1, traditional fine stern edge aerofoil profile is made up of leading edge 21, trailing edge 22, suction surface 20 and acting face 24, and shown in the dotted line among Fig. 1,23 is its string of a musical instrument, and the length of the string of a musical instrument is the chord length of aerofoil profile; And the suction surface 30 of the utility model aerofoil profile is identical with the suction surface 20 of traditional fine stern edge aerofoil profile, and form by leading edge 21, blunt trailing edge 32, suction surface 30 and acting face 34, shown in the solid line among Fig. 1,23 still is its string of a musical instrument, the E point is the common ground of the acting face 34 of traditional fine stern edge aerofoil profile acting face 24 and the utility model aerofoil profile, the E point can change between the 60%-99% chord length apart from the chordwise distance of leading edge 21, and at E point place, the slope of left and right sides acting face is identical.

With reference to Fig. 2, be the local enlarged diagram of the afterbody of traditional fine stern edge aerofoil profile of Fig. 1 and the utility model aerofoil profile.The E point is the common ground of the acting face 34 of traditional fine stern edge aerofoil profile 24 and the utility model aerofoil profile, before the E point, the acting face 24 of fine stern edge aerofoil profile is common with the acting face 34 of the utility model aerofoil profile, the E point can change between the 60%-99% chord length apart from the chordwise distance of leading edge 21, at E point place, the slope of left and right sides acting face is identical; 32 is the blunt trailing edge of aerofoil with blunt tail edge of the present utility model, and its thickness can be 0.5%-3.0% aerofoil profile chord length; 33 is the trailing edge angle of aerofoil with blunt tail edge of the present utility model, (promptly at the trailing edge place, the angle between the tangent line of the tangent line of aerofoil profile suction surface 30 and acting face 34) this trailing edge angle can be that bear or positive, from-75 ° to+60 °, promptly can disperse, also can restrain.

With reference to Fig. 3,, be Re=6.7 * 10 at Reynolds number for the thickness at trailing edge 32 is that 2% aerofoil profile chord length, E point are positioned at when aerofoil profile leading edge 21 is 90% chord length ⁵Under the condition, the lift coefficient of traditional fine stern edge aerofoil profile and the utility model aerofoil profile is with the comparison curve of change in angle of attack, and the lift efficiency of visible aerofoil with blunt tail edge of the present utility model is greatly improved, and its stalling incidence has also been postponed greatly.

With reference to Fig. 4, for the thickness at trailing edge 32 is that 2% chord length, E point are positioned at when aerofoil profile leading edge 21 is 90% chord length, and be 2 ° at the angle of attack, Reynolds number is Re=6.7 * 10 ⁵Under the condition, the liter (power) of traditional fine stern edge aerofoil profile and the utility model aerofoil profile resistance (power) is than the curve that improves percentum, and the aerodynamic characteristics of visible aerofoil with blunt tail edge of the present utility model is greatly improved.

Although the utility model is with regard to subsonic velocity or low speed aerofoil profile and propose, its design philosophy is equally applicable to stride, supersonic aerofoil profile.

Claims

1, a kind of aerofoil with blunt tail edge, form by leading edge (21), suction surface (30), acting face (34) and blunt trailing edge (32), it is before identical with traditional fine stern edge aerofoil profile acting face (24) that described acting face (34) is gone up the E point, suction surface (30) is identical with the suction surface (20) of traditional fine stern edge aerofoil profile, it is characterized in that: the trailing edge of described aerofoil profile is that certain thickness blunt trailing edge (32) is arranged, and its trailing edge thickness is between the aerofoil profile chord length of 0.5%-3.0%.

2, aerofoil with blunt tail edge according to claim 1 is characterized in that: begin to connect with smooth curve to blunt trailing edge (32) from the E point, the E point can change between the aerofoil profile chord length of 60%-99% apart from the chordwise distance of leading edge (21); At E point place, the slope of left and right sides acting face is identical.

3, aerofoil with blunt tail edge according to claim 1 is characterized in that: the trailing edge angle (33) of aerofoil with blunt tail edge can be born, and also can be positive, from-75 ° to+60 °, promptly can disperse, and also can restrain.