CN106741925A - The thickness rotor-blade airfoil of high-lift Low-torque characteristic 12% under the conditions of a kind of full working scope - Google Patents

Abstract

The present invention proposes the thickness rotor-blade airfoil of high-lift Low-torque characteristic 12% under the conditions of a kind of full working scope, and its feature reduces for leading-edge radius, to reduce shock strength, and then reduces resistance, increases lift-drag ratio；Aerofoil profile bottom thickness increased, to reduce torque.Compared by dissipating the rotor-blade airfoil OA312 of Mach number relative thickness 12% with current external disclosed high lift-drag ratio and high-drag, rotor-blade airfoil proposed by the present invention is under the conditions of multi-state, fully meet design objective, with high lift-drag ratio, high-drag dissipates Mach number, maximum lift coefficient high, and moment coefficient is smaller, zero lift drag is smaller during Ma=0.77, meets the performance requirement of high-performance helicopter rotor blade design.

Description

The thickness rotor-blade airfoil of high-lift Low-torque characteristic 12% under the conditions of a kind of full working scope

Technical field

The present invention relates to rotor-blade airfoil design field, specially a kind of full work for being applied to high-performance helicopter rotor 12% thickness rotor-blade airfoil of high lift-drag ratio, maximum lift coefficient high, low zero-lift drag coefficient under the conditions of condition.

Background technology

Helicopter performance is mainly reflected in following two aspect with the substantial connection that advanced rotor-blade airfoil is designed：(1) the rotor wing The lifting of type performance can promote the development of high-performance helicopter, and such as Supercritical Airfoils With Natural Laminar Flow causes aerofoil profile in relative thickness Under conditions of constant, drag divergence Mach number improves 0.05~0.12, or aerofoil profile maximum relative thickness is improved 2%~5%, because This, the lower resistance of the OA5 rotor-blade airfoils series of France, high-drag diverging Mach number characteristic cause the forward flight speed of helicopter, machine Dynamic performance is significantly improved.(2) helicopter is different from the special flight mechanism of Fixed Wing AirVehicle due to it, to Airfoil Design Special index request is proposed, it is necessary to various flight shapes such as winged, motor-driven before satisfaction under harsh pitching moment restrictive condition, hovering To the requirement of aerofoil profile different performance under state.

Initial rotor-blade airfoil be symmetrical airfoil, such as NACA0012, the seventies to the eighties, at the initial stage, have devised resistance The rotor-blade airfoil that diverging Mach number is significantly improved, such as OA-2, Ц А Г И -2 etc..In the phase eighties, France uses numerical optimization Technology design OA3 series aerofoil sections, the later stage eighties-initial stage nineties continues to have developed the rotor-blade airfoil of OA4 and OA5 series, Helicopter performance is set to obtain large increase.

Russia has also carried out a large amount of basic research in terms of high-performance aerofoil profile, has such as developed the profile sets of Ц А Г И 4, And perfect aerofoil profile correlation test equipment and technology has been developed.The Helicopter Corporation such as the U.S. NASA, Xi Kesiji and Bel Carry out high-performance aerofoil profile research in a deep going way, develop various advanced profile sets.These external advanced aerofoil profile data are not external It is open, in technical know-how state.

The current country there is no the invention on high lift-drag ratio rotor-blade airfoil.External existing disclosed 12% thickness rotor-blade airfoil OA312, the profile thickness is identical with the present invention, but other formal parameters are different from the present invention, and lift-drag ratio and maximum lift system Number is also to be hoisted, it is impossible to adapt to helicopter high-performance rotor design demand.

The content of the invention

The technical problem to be solved

Lifting resistance characteristic and maximum lift coefficient of disclosed 12% conventional relative thickness rotor-blade airfoil domestic and international now etc. Have to be hoisted.The purpose of the present invention is, design one kind possesses high lift-drag ratio, maximum lift coefficient high and zero-lift drag coefficient is more 12% low relative thickness aerofoil profile, to meet the performance requirement of high-performance helicopter rotor.

Technical scheme

According to above-mentioned purpose, the present invention proposes a kind of full work for being applied to helicopter high-performance rotor blade design demand Possesses 12% thickness rotor-blade airfoil of high lift-drag ratio, maximum lift coefficient high, Low-torque characteristic under the conditions of condition.Its outstanding feature It is, under the conditions of multi-state, with high lift-drag ratio, maximum lift coefficient high and zero-lift drag coefficient is lower.

The technical scheme is that：

The thickness rotor-blade airfoil of high-lift Low-torque characteristic 12% under the conditions of a kind of full working scope, it is characterised in that：It is described Aerofoil profile upper and lower surface geometric coordinate (x, y) expression formula is respectively：

Wherein subscript up and low represent the upper and lower surface of aerofoil profile respectively, and C is aerofoil profile chord length, and coefficient is：

Further preferred scheme, the thickness rotor-blade airfoil of high-lift Low-torque characteristic 12% under the conditions of a kind of full working scope, It is characterized in that：Coefficient is preferred：

Beneficial effect

Existing disclosed 12% thickness rotor-blade airfoil, is difficult to meet the lift-drag ratio for increasingly being lifted, maximum lift coefficient etc. The requirement of aeroperformance, and the aerofoil profile of present invention design has a high lift-drag ratio, maximum lift coefficient high and zero-lift drag coefficient is more It is low.

Additional aspect of the invention and advantage will be set forth in part in the description, and will partly become from the following description Obtain substantially, or recognized by practice of the invention.

Brief description of the drawings

Of the invention above-mentioned and/or additional aspect and advantage will become from description of the accompanying drawings below to embodiment is combined Substantially and be readily appreciated that, wherein：

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

Fig. 2 is the geometric shape comparison diagram of designing airfoil of the present invention and contrast aerofoil profile；

Fig. 3 is lift coefficient-angle of attack curve comparison of the designing airfoil of the present invention with contrast aerofoil profile in Ma=0.6；

Fig. 4 is lift-drag ratio-lift coefficient curve comparison of the designing airfoil of the present invention with contrast aerofoil profile in Ma=0.6.

Wherein, A is aerofoil profile leading edge, and B is aerofoil profile upper surface postmedian, and C is aerofoil profile upper surface rear portion, and D is aerofoil profile lower surface.

Specific embodiment

Embodiments of the invention are described below in detail, the embodiment is exemplary, it is intended to for explaining the present invention, and It is not considered as limiting the invention.

With the research and development of novel high-performance helicopter, the design of high-performance helicopter rotor-blade airfoil is proposed tightened up Requirement, it is desirable under the conditions of multi-state, with high lift-drag ratio, maximum lift coefficient high, Low-torque characteristic.

The present embodiment is namely based on above-mentioned purpose, devise it is a kind of there is high lift-drag ratio, maximum lift coefficient high and zero liter 12% lower thickness aerofoil profile of resistance coefficient.The full working scope mentioned in text refers to lifting airscrew aerofoil profile when actually used Whole conditions of work.Refer to work bar of the excursion of Mach number from 0.3 to 0.6 for aerofoil profile proposed by the present invention Part.

The aerofoil profile that the present embodiment is proposed is named as NPU-HA-1273, upper and lower according to the family of aerofoil sections that related optimization process is obtained Surface geometry coordinate expressions are respectively：

Wherein subscript up and low represent the upper and lower surface of aerofoil profile respectively, and C is aerofoil profile chord length, and coefficient is as shown in the table：

The geometric expression formula coefficient of NPU-HA-1273 aerofoil profiles

And by numerical computations, above-mentioned coefficient is respectively provided with the aerofoil profile that is obtained in the range of no more than 0.5% of fluctuating Preferable performance.

Corresponding NPU-HA-1273 airfoil geometries feature is as shown in the table：

Aerofoil profile title	Maximum gauge	Maximum gauge position	Maximum camber	Maximum camber position
					NPU-HA-1273	0.119775C	0.294C	-0.023500C	0.231C

The main feature of the aerofoil profile includes：

1st, leading-edge radius reduces, and to reduce shock strength, and then reduces resistance, increases lift-drag ratio；

2nd, aerofoil profile bottom thickness increased, to reduce torque.

In order to illustrate that the aerofoil profile that the present embodiment is proposed has preferable performance, below with OA312 --- a kind of external promotion Resistance than and the rotor-blade airfoil of high-drag diverging Mach number relative thickness 12% aerofoil profile as a comparison, com-parison and analysis its aeroperformances.

Applicant is contrasted by way of numerical computations and wind tunnel test：

Calculating shows, the maximum lift coefficient of aerofoil profile, and the index such as lift-drag ratio has exceeded OA312 aerofoil profiles, only resistance hair comprehensively Scattered Mach number is slightly less than OA312 aerofoil profiles, but zero-lift drag coefficient of the aerofoil profile in Ma0.77 is less than OA312 aerofoil profiles.Calculate knot Fruit see the table below shown.

Designing airfoil and the aeroperformance for contrasting aerofoil profile

Wherein, Cl is lift coefficient, and Ma is Mach number, and K is lift-drag ratio, and Mdd is drag divergence Mach number, and Cm0 is zero liter Moment coefficient, Cd0 is zero-lift drag coefficient.

By result of calculation as can be seen that under the conditions of multi-state, designing airfoil fully meets design objective, with promotion resistance Than, high-drag diverging Mach number, maximum lift coefficient high, and moment coefficient is smaller, zero lift drag is smaller during Ma=0.77.

In Northwestern Polytechnical University NF-3 low-speed wind tunnels and NF-6 high-speed wind tunnels, Airfoil Testing model is machined, carried out The low-speed wind tunnel test static high of rotor-blade airfoil.And be compared with contrast aerofoil profile OA312.Fig. 3 shows, during Ma=0.6, design Wing section lift coefficient is comprehensively higher than contrast aerofoil profile；During Ma=0.6, designing airfoil lift-drag ratio is comprehensively higher than contrast aerofoil profile.

Although embodiments of the invention have been shown and described above, it is to be understood that above-described embodiment is example Property, it is impossible to limitation of the present invention is interpreted as, one of ordinary skill in the art is not departing from principle of the invention and objective In the case of above-described embodiment can be changed within the scope of the invention, change, replace and modification.

Claims (2)

1. the thickness rotor-blade airfoil of high-lift Low-torque characteristic 12% under the conditions of a kind of full working scope, it is characterised in that：In the aerofoil profile Lower surface geometric coordinate (x, y) expression formula is respectively：

$\frac{y_{up}}{C}=0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}\left(1-\frac{x}{C}\right)\·\underset{i=0}{\overset{6}{\mathrm{\Σ}}}\left(A_{{\mathrm{up}}_i}\·\frac{6!}{i!\left(6-i\right)!}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{6-i}\right)$

$\frac{y_{low}}{C}=-0.0025\left(\frac{x}{C}\right)+{\left(\frac{x}{C}\right)}^{0.5}\left(1-\frac{x}{C}\right)\·\underset{i=0}{\overset{6}{\mathrm{\Σ}}}\left(A_{{\mathrm{low}}_i}\·\frac{6!}{i!\left(6-i\right)!}{\left(\frac{x}{C}\right)}^i{\left(1-\frac{x}{C}\right)}^{6-i}\right)$

Wherein subscript up and low represent the upper and lower surface of aerofoil profile respectively, and C is aerofoil profile chord length, and coefficient is：

$A_{{\mathrm{up}}_0}=0.182*(1\±0.5\%),A_{{\mathrm{up}}_1}=0.343*(1\±0.5\%),A_{{\mathrm{up}}_2}=0.0425*(1\±0.5\%),$

$A_{{\mathrm{up}}_3}=0.350*(1\±0.5\%),A_{{\mathrm{up}}_4}=0.103*(1\±0.5\%),A_{{\mathrm{up}}_5}=0.238*(1\±0.5\%),$

$A_{{\mathrm{up}}_6}=-0.0545*(1\±0.5\%);$

$A_{{\mathrm{low}}_0}=-0.118*(1\±0.5\%),A_{{\mathrm{low}}_1}=-0.0694*(1\±0.5\%),A_{{\mathrm{low}}_2}=-0.100*(1\±0.5\%),$

$A_{{\mathrm{low}}_3}=-0.150*(1\±0.5\%),A_{{\mathrm{low}}_4}=2.33*(1\±0.5\%),A_{{\mathrm{low}}_5}=-0.242*(1\±0.5\%),$

$A_{{\mathrm{low}}_6}=-2.50*(1\±0.5\%).$

2. the thickness rotor-blade airfoil of high-lift Low-torque characteristic 12% under the conditions of a kind of full working scope according to claim 1, it is special Levy and be：Coefficient is preferred：

$A_{{\mathrm{up}}_0}=0.1821118,A_{{\mathrm{up}}_1}=0.3436739,A_{{\mathrm{up}}_2}=0.0425914,A_{{\mathrm{up}}_3}=0.3505050,$

$A_{{\mathrm{up}}_4}=0.1031169,A_{{\mathrm{up}}_5}=0.2385890,A_{{\mathrm{up}}_6}=-0.0545979;$

$A_{{\mathrm{low}}_0}=-0.118319,A_{{\mathrm{low}}_1}=-0.069490,A_{{\mathrm{low}}_2}=-0.1000549,A_{{\mathrm{low}}_3}=-0.1507907,$

$A_{{\mathrm{low}}_4}=2.3304491,A_{{\mathrm{low}}_5}=-0.2426400,A_{{\mathrm{low}}_6}=-\mathrm{2.5073795.}$