CN102642613A

CN102642613A - Low-resistance fairing of corrugate sheath

Info

Publication number: CN102642613A
Application number: CN201210146223XA
Authority: CN
Inventors: 王勇; 柴建忠
Original assignee: Xian Aircraft Design and Research Institute of AVIC
Current assignee: Xian Aircraft Design and Research Institute of AVIC
Priority date: 2012-05-11
Filing date: 2012-05-11
Publication date: 2012-08-22
Anticipated expiration: 2032-05-11
Also published as: CN102642613B

Abstract

The invention belongs to the technical field of airplane design, and relates to a low-resistance fairing of a corrugate sheath, which is improved on a plane fairing part. The fairing consists of a fairing head part, a fairing back part, a fairing corrugate sheath, a resilient surface rubber, a plane body surface and a through hole, wherein the fairing head part is fixedly riveted or bonded on the plane body surface, the through hole is arranged at the most front end of the fairing head part, i.e. near an airflow stationary point, the through hole is communicated with an inner cavity of the fairing, the fairing corrugate sheath is arranged in the position with the biggest cross section area of the fairing, the fairing corrugate sheath is bonded between the fairing head part and the fairing back part, and the resilient surface rubber is bonded on the outer surface of a wave crest position of the corrugate sheath. The low-resistance fairing of the corrugate sheath disclosed by the invention can be balanced between pressure drag and frictional drag, the shape of the fairing is self-adaptively changed according to flight speed, flow separation on the fairing under a high-speed condition is restrained, and the vortex intensity at the tail part of the fairing is improved, so that the differential pressure between the front and the back of the fairing is reduced and the plane flight resistance is reduced.

Description

Radiation fins low-resistance fairing

Technical field:

The invention belongs to the airplane design technical field, relate to a kind of the improved radiation fins low-resistance of aircraft radome parts fairing.

Background technology

Existing subsonic aircraft extensively adopts Fig. 1, fairing profile shown in Figure 2, to reduce the flight resistance of aircraft.Fairing generally according to following current to layout, adopt the head of raindrop type, the afterbody of wedge shape; Generally about 10 degree, this fairing can well reduce pressure drag to the air-flow angle of diffusion of afterbody in certain particular speed range, still; When the increase along with flying speed, after certain speed, the fairing overdraught can separate; Form the turbulent region of afterbody, i.e. whirlpool, the pressure in whirlpool district is less than the pressure in anterior incoming flow district; Thereby difference of pressure before and after forming, pressure direction is pressure drag backward backward.The slenderness ratio of this fixed fairing is invariable, and the drag reduction advantage is only in the certain speed scope.According to the aerodynamic force characteristics on the fairing, good fairing hopes that slenderness ratio can regulate according to aircraft flight speed, and avoiding the appearance in afterbody whirlpool district, and the fairing of existing aircraft does not possess this characteristics.

Summary of the invention

The objective of the invention is to propose the radiation fins low-resistance fairing that a kind of slenderness ratio of aircraft radome can be regulated according to aircraft flight speed.Technical solution of the present invention is, described fairing is by the fairing head, the fairing rear portion; The fairing radiation fins, surface elasticity rubber, body surface; Through hole is formed, the fixing riveted joint of fairing head or be bonded on the airframe surface, and at the fairing head is to stay a through hole near the air-flow stationary point foremost; Through hole and fairing inner chamber connect; At area place, the maximum cross section of fairing a fairing radiation fins is set, fairing radiation fins front end is bonded on the aft end face of fairing head, and the rear end of fairing radiation fins is connected the fairing rear portion; The rear end of fairing radiation fins is connected the front end at fairing rear portion; The gap of 1-5mm is left at fairing rear portion and the position that body surface suits mutually, and body surface slides in the drive lower edge of fairing radiation fins to make the fairing rear portion, and surface elasticity rubber is bonded in the outside face of radiation fins crest location.

The described fairing radiation fins that is provided with at area place, the maximum cross section of fairing, its length is the 8-15% of whole fairing total length.

Advantage that the present invention has and beneficial effect,

The present invention increases the elastic corrugated shape god cover that contracts at existing fairing the maximum cross-section area place; The outside face of radiation fins crest location be bonded with can guarantor's type elasticity rubber [4]; Can change the fairing slenderness ratio automatically according to differential pressure conditions before and after the fairing; Thereby little area and the little friction drag of soaking arranged when taking into account the aircraft low-speed operations, suitable slenderness ratio and little pressure drag are arranged during high-speed flight, thereby improve the aircraft drag characteristic of each flying speed.

Radiation fins low-resistance fairing of the present invention; Can between pressure drag, friction drag, weigh; According to the shape of flying speed adaptively changing fairing, suppress the burbling on the fairing under the big speed conditions, improve the vortex strength degree of fairing afterbody; Thereby pressure reduction reduces before and after making fairing, reduces the flight resistance of aircraft.

A lot of fairings is arranged on the aircraft, and all fairings all adopt this technology, will play considerable drag-reduction effect, and are of great advantage for 1ift-drag ratio, the increase voyage of lifting aircraft.

The present invention is traditional fairing segmentation, increases the unitized construction of the flexible radiation fins of a cover, plasticity rubber, and is simple in structure, operability is very strong.

Description of drawings

Fig. 1 is existing aircraft typical case fairing front view;

Fig. 2 is existing aircraft radome generalized section;

Fig. 3 is that fairing master of the present invention looks scheme drawing;

Fig. 4 is that fairing of the present invention elevation profile connects scheme drawing;

Fig. 5 is that the elevation profile of fairing radiation fins extended state of the present invention connects scheme drawing.

The specific embodiment

Below in conjunction with accompanying drawing the present invention is elaborated.

Described fairing is by fairing head 1, fairing rear portion 2, and fairing radiation fins 3, surface elasticity rubber 4, body surface 5, through hole 6 is formed.The fixing riveted joint of fairing head 1 or be bonded on the airframe surface 5, at fairing head 1 is to stay a through hole 6, through hole and the perforation of fairing inner chamber near the air-flow stationary point foremost.Fairing radiation fins 3 front ends are bonded on the aft end face of fairing head 1, and the rear end of fairing radiation fins [3] is connected with fairing rear portion 2, and fairing radiation fins 3 vertically has good retractility, has good support rigidity in other directions.Surface elasticity rubber 4 is bonded in the radiation fins outside, and bonding position is the crest location of radiation fins.

Its principle of work of described fairing is: when air speed was 0, fairing radiation fins 3 was in free state, and it is minimum that the slenderness ratio of whole fairing keeps; Length is minimum, soaks the area minimum, when aircraft flight; Through hole [6] can guarantee that the pressure in the chamber is consistent with near the pressure the stationary point, is maximum pressure, and the pressure of fairing rear end can be smaller; In the chamber with the difference of pressure effect of fairing rear end under; Can spur scalable fairing radiation fins [3], change the slenderness ratio of fairing, reach new force balance.When air speed was very high, the pressure drag that the burbling on the fairing is brought was the principal element of resistance, and the external and internal pressure difference of this moment is bigger; Can drive ripple and be with bigger amount of tension; Thereby largely change the slenderness ratio of fairing, suppress burbling, reduce pressure drag.

The fairing that is 800mm with existing total length is an example, makes improvements, and fairing adopts raindrop type head, wedge shape afterbody, being the maximum cross section apart from fairing front end 300mm place, fairing is divided into two parts, i.e. fairing head 1, fairing rear portion 2.Fairing head 1 fixedly is riveted on the airframe surface 5, fairing head 1 be to stay a through hole 6 near the air-flow stationary point foremost, through-hole diameter is 2mm.Fairing radiation fins 3 front ends are bonded on the aft end face of fairing head 1, and the rear end of fairing radiation fins 3 is connected with fairing rear portion 2, and fairing radiation fins 3 vertically has good retractility, has good support rigidity in other directions.Surface elasticity rubber 4 is bonded in radiation fins 3 outsides, and bonding position is the crest location of radiation fins 3, to guarantee the outside face fairing of fairing.

Radiation fins low-resistance fairing principle of work is: when air speed was 0, the fairing radiation fins was in free state, and it is minimum that the slenderness ratio of whole fairing keeps, and length is minimum; Soak the area minimum, the pressure in the cavity is consistent with local outside pressure, and when aircraft flight arrived 350km/h, the fairing local air flow separated; Afterbody forms eddy zone, and the pressure at place, stationary point this moment is 1.26 times external atmosphere pressure, and pressure also is 1.26 times external atmosphere pressure in the chamber, and fairing rear portion eddy zone pressure is 0.73 times external atmosphere pressure; Under the inside and outside differential pressure effect, radiation fins has extended 76mm, has effectively slowed down the burbling of fairing; Suppressed trailing vortex intensity, simultaneously, elasticity rubber is along with radiation fins stretches together; Play the effect of good guarantor's type, guaranteed fairing outside face fairing streamline, reduced pressure drag.

Described dome structure is simple, easy operating, and it can be weighed between pressure drag, friction drag, according to the shape of flying speed adaptively changing fairing, has stronger practicality.

Claims

1. radiation fins low-resistance fairing is characterized in that: described fairing is by fairing head [1], fairing rear portion [2]; Fairing radiation fins [3], surface elasticity rubber [4], body surface [5]; Through hole [6] is formed; The fixing riveted joint of fairing head [1] or be bonded on the airframe surface [5], at fairing head [1] is to stay a through hole [6], through hole and the perforation of fairing inner chamber near the air-flow stationary point foremost; At the maximum cross-section area place of fairing a fairing radiation fins [3] is set; Fairing radiation fins [3] front end is bonded on the aft end face of fairing head [1], and the rear end of fairing radiation fins [3] is connected the front end of fairing rear portion [2], and the gap of 1-5mm is left at fairing rear portion [2] and the position that body surface [5] suits mutually; Body surface slides in the drive lower edge of fairing radiation fins [3] to make fairing rear portion [2], and surface elasticity rubber [4] is bonded in the outside face of radiation fins crest location.

2. a kind of radiation fins low-resistance fairing according to claim 1 is characterized in that: the described fairing radiation fins [3] that is provided with at the maximum cross-section area place of fairing, its length is 8-15% of whole fairing total length.