CN105752315A - New-concept airfoil profile with combined transonic-velocity and hypersonic-velocity aerodynamic properties - Google Patents

Abstract

The invention provides a new-concept airfoil profile with combined transonic-velocity and hypersonic-velocity aerodynamic properties.The maximum thickness of the new-concept airfoil profile is 4.0%C, the maximum-thickness position of the new-concept airfoil profile is 47.4%C, the maximum bending of the new-concept airfoil profile is 1.17%, the maximum-bending position of the new-concept airfoil profile is 74.4%C, and the C represents chord lengths of the new-concept airfoil profile.The new-concept airfoil profile with the combined transonic-velocity and hypersonic-velocity aerodynamic properties has the advantages that lift-to-drag characteristics of the new-concept airfoil profile in hypersonic-velocity states are superior to lift-to-drag characteristics of conventional hypersonic-velocity airfoil profiles, the new-concept airfoil profile in transonic-velocity states is excellent in lift-to-drag characteristic as compared with the conventional hypersonic-velocity airfoil profiles, and accordingly requirements on properties of hypersonic-velocity aircrafts in transonic-velocity climbing phases and hypersonic-velocity cruise phases can be met.

Description

Take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance

Technical field

The invention belongs to Airfoil Design technical field, be specifically related to a kind of take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance.

Background technology

Hypersonic aircraft generally refers to the flight speed aircraft more than the aircraft of 5 times of velocities of sound, guided missile, shell etc.Have the advantages that prominent anti-success rate is high, have huge military value and potential economic worth.

Along with space application and space exploration activity day by day frequently, the application demand of cheap, quick, the motor-driven and reliable hypersonic aircraft meeting various space transportation task is increasingly urgent.At present, territory is wider, direction wider, that voyage is farther, spatial domain is developed towards speed for hypersonic aircraft.

After hypersonic aircraft takes off from ground, experience transonic speed ramp-up period, until multiple mission phase such as hypersonic cruise.Therefore, for hypersonic aircraft, except needs ensure hypersonic performance, it is necessary to have both the transonic characteristics meeting engineering demand.Concrete, in transonic speed ramp-up period, should have bigger lift-drag ratio；In hypersonic cruising phase, owing to flying near space, Aerodynamic Heating and surrounding flow field density diminish, face the interference of stronger viscosity, high-temperature gas impact and low density flow dynamic characteristic, wave resistance and frictional resistance are quickly increased, define " lift-drag ratio barrier ", in order to break through hypersonic " lift-drag ratio barrier ", it is desirable to improve lift-drag ratio as far as possible.Therefore, for the design of hypersonic aircraft aerofoil profile, its difficult point is that what how to solve hypersonic aerodynamic characteristic and transonic speed aerodynamic characteristic takes into account problem.

The hypersonic aerofoil profile of routine conventional in reality, mostly adopts the cross-sectional profile such as tetragon, hexagon, although have high lift-drag ratio under hypersonic state, can meet the performance need of hypersonic cruising phase；But under transonic speed state, aerofoil profile lifting resistance characteristic is poor, it is impossible to take into account the aeroperformance under transonic speed state, therefore, it is impossible to meet the hypersonic aircraft performance need in transonic speed ramp-up period.So, in prior art, the design of the hypersonic aerofoil profile in wide speed territory remains technological difficulties.

Summary of the invention

For prior art exist defect, the present invention provide a kind of take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance, can effectively solve the problems referred to above.

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

The present invention provide a kind of take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance, the maximum gauge of this new ideas aerofoil profile is 4.0%C, and maximum gauge position is 47.4%C, maximum camber is 1.17%C, maximum camber position is 74.4%C, and wherein, C is aerofoil profile chord length.

Preferably, 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 airfoil geometry coordinate

Provided by the invention taking into account transonic speed has the advantage that with the new ideas aerofoil profile of hypersonic aeroperformance

Provided by the invention take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance, its lifting resistance characteristic under hypersonic state is better than conventional hypersonic aerofoil profile, and than conventional hypersonic aerofoil profile, there is more excellent lifting resistance characteristic under transonic speed state, thus meet the transonic speed ramp-up period of hypersonic aircraft and the performance need of hypersonic cruising phase.

Accompanying drawing explanation

Fig. 1 is the geometric shape figure of designing airfoil of the present invention；

Fig. 2 is the geometric shape figure of the designing airfoil of the present invention after Fig. 1 equal proportion is amplified；

Fig. 3 is the designing airfoil of the present invention pressure distribution curve figure (Ma=0.8) in transonic speed design point；

Fig. 4 is the designing airfoil of the present invention pressure distribution curve figure (Ma=6) in hypersonic design point；

Fig. 5 is the geometric shape comparison diagram of designing airfoil of the present invention and contrast aerofoil profile；

Fig. 6 is designing airfoil of the present invention and contrasts the aerofoil profile pressure distribution curve comparison diagram in transonic speed design point；

Fig. 7 is designing airfoil of the present invention and contrasts the aerofoil profile pressure distribution curve comparison diagram in hypersonic design point；

Fig. 8 is designing airfoil of the present invention and contrasts the aerofoil profile lift efficiency curve comparison figure in transonic speed design point；

Fig. 9 is designing airfoil of the present invention and contrasts the aerofoil profile lift efficiency curve comparison figure in hypersonic design point；

Figure 10 is designing airfoil of the present invention and contrasts the aerofoil profile lift-drag ratio characteristic curve comparison diagram in transonic speed design point；

Figure 11 is designing airfoil of the present invention and contrasts the aerofoil profile lift-drag ratio characteristic curve comparison diagram in hypersonic design point；

Wherein:

A is aerofoil profile leading edge

B is aerofoil profile upper surface

C is that aerofoil profile lower surface is anterior

D is aerofoil profile lower surface rear portion

1 is geometry and the calculation of aerodynamic characteristics result thereof of designing airfoil of the present invention；

2 is contrast aerofoil profile, i.e. the geometry of conventional hypersonic aerofoil profile tetragon aerofoil profile and aerodynamic characteristics numerical simulation result of calculation thereof；

Wherein:

The state that transonic speed calculates is: height 9 kms, Mach number 0.8, Reynolds number 7.6 × 10⁶；

Hypersonic calculating state is: height 26 kms, Mach number 6, Reynolds number 4.23 × 10⁶。

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.

At present both at home and abroad but without be applied to hypersonic aircraft take into account transonic speed with the correlation technique of the aerofoil profile of hypersonic performance.The present invention provide a kind of take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance, its lifting resistance characteristic under hypersonic state is better than conventional hypersonic aerofoil profile, and than conventional hypersonic aerofoil profile, there is more excellent lifting resistance characteristic under transonic speed state, the performance need of transonic speed ramp-up period and hypersonic cruising phase to meet hypersonic aircraft.

Concrete, the present invention design a kind of take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance, its outstanding feature is: aerofoil profile maximum gauge position is located adjacent to 50% place, and the change of aerofoil profile upper surface is mild so that it has good lifting resistance characteristic under transonic speed state；Aerofoil profile lower surface is anti-" S " type by edge, and loading before being formed time transonic speed increases lift, forms isentropic Compression ripple, increase lift and improve lift-drag ratio time hypersonic；Aerofoil profile lower surface edge place rearward is " S " type, and loading after being formed time transonic speed to increase lift, time hypersonic, passes through second-compressed, it is ensured that the lifting resistance characteristic under hypersonic state；Aerofoil profile leading edge has small radii, to ensure aerofoil profile high lift-drag ratio under hypersonic state.

The aerofoil profile called after NPU-Hyper-04 of the present invention, as depicted in figs. 1 and 2, geometric shape figure for designing airfoil of the present invention, there is following geometric properties: maximum gauge is 4.0%C, maximum gauge position is 47.4%C, and maximum camber is 1.17%C, and maximum camber position is 74.4%C, 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 airfoil geometry coordinate

For NPU-Hyper-04 aerofoil profile provided by the invention, its transonic speed design point be height 9 kms, Mach number 0.8, Reynolds number 7.6 × 10⁶, the angle of attack 1.5 °；Hypersonic design point is height 26 kms, Mach number 6, Reynolds number 4.23 × 10⁶, the angle of attack 5 °.Specific design index is:

1, under hypersonic state, there is high lift-drag ratio；

2, transonic speed under state, the lift-drag ratio under the design angle of attack is not less than 68, and the lift coefficient under the design angle of attack is not less than 0.6387；

3, under hypersonic state, the lift coefficient under the design angle of attack is not less than 0.045；

4, leading-edge radius is not less than 0.1%C；

5, profile thickness is within the scope of 4%C ± 0.02%C.

As shown in Figures 1 to 4, aerofoil profile leading edge A has small radii, to ensure aerofoil profile high lift-drag ratio under hypersonic state.Aerofoil profile upper surface B change is mild, ensures that it has good lifting resistance characteristic under transonic speed state as far as possible.Aerofoil profile maximum gauge position is located adjacent to 50%C place, and lower surface leans on edge, and namely aerofoil profile lower surface front portion C is anti-" S " type, and loading before being formed time transonic speed increases lift, forms isentropic Compression ripple, increase lift and improve lift-drag ratio time hypersonic；Aerofoil profile lower surface edge place rearward, namely aerofoil profile lower surface rear portion D is " S " type, and loading after being formed time transonic speed to increase lift, time hypersonic, passes through second-compressed, it is ensured that hypersonic lifting resistance characteristic.

The hypersonic Airfoil Design of existing routine is mostly just for hypersonic flowing, the aerofoil profile of the present invention, it is possible to while the high lift-drag ratio under ensure that hypersonic state, also has excellent lifting resistance characteristic under transonic speed state.Therefore, the present invention design aerofoil profile, transonic speed with under hypersonic flight state, be respectively provided with high coefficient of lift combined and high lift-drag ratio.

Below by way of experiment effect example, the advantage of NPU-Hyper-04 aerofoil profile provided by the invention is verified:

Checking example 1

With the hypersonic aerofoil profile aerofoil profile as a comparison of conventional quadrangle form, contrast with designing airfoil of the present invention, the difference of the aeroperformance of com-parison and analysis designing airfoil of the present invention and contrast aerofoil profile.

Concrete, the profile thickness of the contrast aerofoil profile chosen is 4%C, and maximum gauge position is 50%C, and front chamfering radius is 0.1%C.The state that transonic speed calculates is: height 9 kms, Mach number 0.8, Reynolds number 7.6 × 10⁶, the angle of attack 1.5 °；Hypersonic calculating state is: height 26 kms, Mach number 6, Reynolds number 4.23 × 10⁶, the angle of attack 5 °.

With reference to Fig. 5, for the geometric shape comparison diagram of designing airfoil of the present invention with contrast aerofoil profile；With reference to Fig. 6, for pressure distribution curve comparison diagram in transonic speed design point of designing airfoil of the present invention and contrast aerofoil profile；With reference to Fig. 7, for pressure distribution curve comparison diagram in hypersonic design point of designing airfoil of the present invention and contrast aerofoil profile；With reference to Fig. 8, for lift efficiency curve comparison figure in transonic speed design point of designing airfoil of the present invention and contrast aerofoil profile；With reference to Fig. 9, for lift efficiency curve comparison figure in hypersonic design point of designing airfoil of the present invention and contrast aerofoil profile；With reference to Figure 10, for lift-drag ratio characteristic curve comparison diagram in transonic speed design point of designing airfoil of the present invention and contrast aerofoil profile；With reference to Figure 11, for lift-drag ratio characteristic curve comparison diagram in hypersonic design point of designing airfoil of the present invention and contrast aerofoil profile.Referring to table 2, for the aeroperformance contrast table of designing airfoil of the present invention with contrast aerofoil profile:

Table 2: designing airfoil and the aeroperformance contrasting aerofoil profile

By observing Fig. 4-Figure 11 and table 2 it can be seen that under hypersonic state, present invention lift-drag ratio under the design angle of attack reaches 5.942, and contrasting aerofoil profile lift-drag ratio is 5.499；Under transonic speed state, the present invention designs the lift-drag ratio under the angle of attack and reaches 78.90, and lift coefficient reaches 0.650, and the lift-drag ratio contrasting aerofoil profile is only 24.07, and lift coefficient is only 0.274.As can be seen here, aerofoil profile provided by the invention, transonic speed with under hypersonic flight state, be respectively provided with high coefficient of lift combined and high lift-drag ratio, fully met the design needs of hypersonic aircraft.

Checking example 2

Inventor uses the aeroperformance of numerical calculations NPU-Hyper-04 aerofoil profile of the present invention, and the state that transonic speed calculates is: height 9 kms, Mach number 0.8, Reynolds number 7.6 × 10⁶；Hypersonic calculating state is: height 26 kms, Mach number 6, Reynolds number 4.23 × 10⁶.Result of calculation is as shown in table 3:

The numerical simulation calculation result of table 3 designing airfoil

As can be seen from Table 3, under hypersonic state, designing airfoil fully meets design objective, has high lift-drag ratio；And under transonic speed state, designing airfoil also has high-lift and high lift-drag ratio.As can be seen here, the aerofoil profile designed by the present invention can take into account transonic speed with hypersonic aerodynamic characteristic.

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 (2)

1. one kind take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance, it is characterised in that the maximum gauge of this new ideas aerofoil profile is 4.0%C, maximum gauge position is 47.4%C, and maximum camber is 1.17%C, and maximum camber position is 74.4%C, wherein, C is aerofoil profile chord length.

2. according to claim 1 take into account transonic speed with the new ideas aerofoil profile of hypersonic aeroperformance, it is characterised in that the geometric coordinate expression formula of this aerofoil profile upper and lower surface is respectively as follows:

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

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

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 airfoil geometry coordinate