CN101560929B - Variable incidence scramjet engine outboard cowl - Google Patents

Abstract

The variable inclination scramjet outer fairing of the present invention comprises side walls and a fixed lower wall surface, side walls are arranged on both sides of the fixed lower wall surface, and the rotary shaft provided on the lip below the fixed lower wall surface is hingedly connected with an adjustable The lower wall surface, the adjustable lower wall surface is powered by the drive mechanism to deflect around the rotary shaft, and the deflection position of the adjustable lower wall surface is defined by the limit locking mechanism. In the variable inclination scramjet outer fairing of the present invention, an adjustable lower wall deflecting around the lip of the fixed lower wall is arranged below the fixed lower wall of the scramjet outer cowling, and the inclination of the adjustable lower wall is adjusted , realize the change of the aerodynamic performance of the aircraft, and then obtain the optimal aerodynamic performance under different flight states.

Description

A scramjet outer fairing with variable inclination angle

technical field

The invention relates to a technology for configuration design of a hypersonic aircraft with a scramjet engine as a power system, in particular to a high aerodynamic performance outer fairing of a scramjet engine.

Background technique

A hypersonic vehicle is one that travels in the atmosphere and across the atmosphere at speeds of Mach 5 or higher. When the aircraft flies at hypersonic speed, the wave resistance and frictional resistance increase sharply, which leads to the increase of aerodynamic resistance and the decrease of engine thrust margin, resulting in a serious thrust-drag matching problem. In order to reduce drag and increase lift, and ensure the overall performance of the aircraft, the fuselage and engine are generally designed with a high degree of integration, that is, the front of the fuselage is integrated with the engine inlet, and the rear of the fuselage is integrated with the exhaust nozzle of the engine. One.

43A Hypersonicvehicle technology development.Acta Astronautica.2006.59：181-191)、正在研制的X-51飞行器(参见Graham W，Hyper reality，Aviation Week & Space Technology，2008：6

64)、还是各国研发的其他飞行器(如Timothy F.O’Brien.and M J Lewis，Rocket-BasedCombined-Cycle Engine Integration on an Osculating ConeWaverider Vehicle.Journal of Aircraft.2001.38(6)：1111123和Lobbia M.Suzuki K.Numerical Investigation of

Derived HypersonicTransport Configurations.AAA 2003-3804，2003等)均采用这种配置方案。在这种方案中，飞行器前体一般采用乘波体的构型设计方案，除提供飞行器所需的部分升力和俯仰力矩外，还需充当发动机进气道的预压缩面。后体一般采用单壁扩张喷管的配置形式，主要用以提供飞行器的推力，同时也要产生升力和俯仰力矩(见K G Bowcuttetal，Advancementsin Multidisciplinary DesignOptimization Applied to Hypersonic Vehicles to Achieve Closure，AIAA-2008-2591，2008)。Hypersonic aircraft powered by scramjet engines can generally be divided into three parts: the front body, the engine, and the rear body. Whether it is the X-43A aircraft that has been tested in the United States (see Voland R T. Huebner L D. and McClinton C R .

43A Hypersonic vehicle technology development. Acta Astronautica.2006.59: 181-191), the X-51 aircraft under development (see Graham W, Hyper reality, Aviation Week & Space Technology, 2008: 6

64), or other aircraft developed by various countries (such as Timothy F.O'Brien.and M J Lewis, Rocket-Based Combined-Cycle Engine Integration on an Osculating ConeWaverider Vehicle.Journal of Aircraft.2001.38(6): 111 1123 and Lobbia M. Suzuki K. Numerical Investigation of

Derived HypersonicTransport Configurations. AAA 2003-3804, 2003, etc.) all adopt this configuration scheme. In this scheme, the aircraft precursor generally adopts the configuration design scheme of the waverider. In addition to providing part of the lift and pitching moment required by the aircraft, it also needs to serve as the pre-compression surface of the engine inlet. The rear body generally adopts the configuration form of a single-wall expansion nozzle, which is mainly used to provide the thrust of the aircraft, and also to generate lift and pitching moment (see K G Bowcutt et al, Advancements in Multidisciplinary Design Optimization Applied to Hypersonic Vehicles to Achieve Closure, AIAA-2008-2591 , 2008).

Among the three components of the above-mentioned aircraft, the aircraft front body (waverider body) and the rear body are hot research issues in recent years, and there are many related documents, such as (Pan and Yan, Aerodynamic study of three waveriders ba sed on a new optimization process, AIAA-2008-170, 2008) and (D Kliche et al, Multidisciplinary Analysis and Evaluation of Superosnic Combustion Ramjets, AIAA-2008-2602, 2008), etc., their research goals are mainly to analyze and optimize the design of precursors and The shape of the rear body achieves the purpose of improving the lift-to-drag ratio of the aircraft or increasing the thrust. The research on the engine part of the aircraft is currently mainly focused on the inner runner part of the engine, including the design of the inlet, combustion chamber, isolation section, etc., and a large number of related documents and patents can also be consulted. However, for the outer fairing of the engine, especially the research on the configuration design of the outer fairing to improve the aerodynamic performance, no relevant documents or patents have been found. In terms of proportion, the length of the engine part generally accounts for more than 1/3 of the length of the entire hypersonic aircraft. Therefore, if this part can be effectively used, the aerodynamic performance of the entire aircraft can be improved to a large extent.

The flight state of a hypersonic vehicle generally includes two states: acceleration and cruise. When the aircraft is in accelerated flight, it is necessary to increase the net thrust of the engine as much as possible, or to minimize the drag of the aircraft. When in the cruising flight state, it is necessary to increase the lift-to-drag ratio of the aircraft under the condition of ensuring that the engine thrust matches the resistance of the aircraft to obtain a greater flight range. Obviously, different flight states lead to different aircraft configuration requirements. From the perspective of the overall composition of the aircraft, compared with the front body and the rear body of the aircraft, the outer fairing part of the engine undertakes relatively few functions and is weakly coupled with other components. Some interfere. The present invention proposes based on the above background.

Contents of the invention

Based on the above background, the purpose of the present invention is to provide a different flight state for the aircraft, apply the concept of deformable aircraft, and realize the change of the aerodynamic performance of the aircraft by changing the angle of the lower wall surface of the outer fairing of the engine, and then in different flight states. for optimum aerodynamic performance.

In order to achieve the above object, the variable inclination scramjet outer fairing of the present invention comprises a side wall and a fixed lower wall surface, the side walls are arranged on both sides of the fixed lower wall surface, and the rotary shaft arranged on the lip below the fixed lower wall surface An adjustable lower wall is hingedly connected, and the adjustable lower wall is powered by a driving mechanism to deflect around the rotary shaft, and the deflection position of the adjustable lower wall is defined by a limit locking mechanism.

Further, the fixed lower wall surface and the adjustable lower wall surface have the same shape, wherein the fixed lower wall surface and the adjustable lower wall surface are plane or curved surfaces.

Further, when the adjustable lower wall surface is a curved surface, the convex surface of the adjustable lower wall surface is installed upward on the rotary shaft.

Further, the shape of the side wall is a quadrangular plane, and the lower edge of the side wall is a straight line that slopes downward starting from the lip of the fixed lower wall, and the angle of inclination does not exceed 8°.

Further, when the adjustable lower wall surface is a plane or a curved surface, the lowest deflection position of the bottom surface of the adjustable lower wall surface is not lower than the plane formed by the lower edges of the two side walls.

Further, the driving device is an elastic pull device provided at the tail of the fixed lower wall, and the elastic pull device provides power to the adjustable lower wall, so that the adjustable lower wall deflects toward the bottom edge of the side wall or moves toward the bottom edge of the side wall. Fixed lower wall orientation deflection.

Further, the elastic pulling device is a strong elastic device or a small explosive driving device.

Further, the position-limiting locking mechanism includes a guide rail provided on the side wall and a sliding guide rod slidingly fitted with the guide rail, the guide rail extends from the fixed lower wall facing the bottom edge of the side wall and ends at the bottom edge of the side wall , the sliding guide rod is arranged on the adjustable lower wall surface, and erected in the guide rails on the two side walls, when the sliding guide rod moves to the cut-off position of the guide rail, both ends are clamped in the grooves at the cut-off position of the guide rail.

In the variable inclination scramjet outer fairing of the present invention, an adjustable lower wall deflecting around the lip of the fixed lower wall is arranged below the fixed lower wall of the scramjet outer cowling, and the inclination of the adjustable lower wall is adjusted , realize the change of the aerodynamic performance of the aircraft, and then obtain the optimal aerodynamic performance under different flight states. When the aircraft is in the state of accelerated flight, the movable lower wall has no deflection and coincides with the fixed lower wall. At this time, the frontal area of the aircraft is relatively minimum, and the inclination angle of the adjustable lower wall is relatively small, which is beneficial to reduce the differential pressure resistance and excitation of the aircraft. wave resistance. When the aircraft is in the cruising flight state, the movable lower wall deflects downward (clockwise) at a certain angle (the specific deflection value is determined by environmental conditions such as flight altitude, flight Mach number, and flight angle of attack). As the area increases, the movable lower wall can generate additional lift by compressing the incoming flow. Although the drag increases at the same time, the lift-to-drag ratio can be effectively improved, which is beneficial to the increase of the flight range of the aircraft.

Description of drawings

Fig. 1 is the structural representation of scramjet outer fairing of the present invention;

Figure 2 is a two-dimensional configuration diagram of a hypersonic vehicle;

Fig. 3 is a pressure distribution contour map of the configuration in Fig. 2;

Fig. 4a is the schematic diagram of deflecting 2° of the movable lower wall surface of the outer fairing of the present invention;

Fig. 4b is a schematic diagram of a 4° deflection of the movable lower wall of the outer fairing of the present invention;

Fig. 4c is a schematic diagram of a 6° deflection of the movable lower wall of the outer fairing of the present invention;

Figure 4d is a schematic diagram of an 8° deflection of the movable lower wall of the outer fairing of the present invention;

Fig. 5 is a schematic diagram of the side wall of the present invention.

Detailed ways

As shown in Figure 1, the scramjet outer fairing with variable inclination includes side wall 2 and fixed lower wall surface 3, the side walls 2 are arranged on both sides of the fixed lower wall surface 3, and the lower part of the fixed lower wall surface 3 is arranged on its lip The rotary shaft 1 is hingedly connected with an adjustable lower wall 4, which is powered by a driving mechanism to deflect around the rotary shaft 1, and the deflection position of the adjustable lower wall 4 is defined by a limit locking mechanism.

As shown in Figure 5, the side wall 2 is provided with a guide rail 21, and the adjustable lower wall 4 is provided with a sliding guide rod 41 that can slide in the guide rail 21, and the sliding guide rod 41 is erected in the guide rail 21 on the two side walls 2 , the adjustable lower wall 4 is connected to the fixed lower wall 3 through a spring-pull device 5, the spring-pull device 5 can eject or pull up the adjustable lower wall 4 downwards or upwards, and the spring-pull device 5 gives the adjustable lower wall 4 With the downward power, the sliding guide rail 41 on the adjustable lower wall 4 moves downward along the guide rail 21, so that the adjustable lower wall 4 moves downward. When the sliding guide rod 41 moves to the bottom position of the side wall 2, it is locked. In the groove 22 provided on the side wall 2, the adjustable lower wall surface 4 is fixed at this position; the elastic pull device 5 gives the upward pulling force to the adjustable lower wall surface 4, and the adjustable lower wall surface 4 can return to the fixed lower wall surface 3 overlapping positions.

The main design idea of the present invention is shown in Figure 1 (here taking the fairing on the lower wall of the curved surface as an example), which includes three parts: side wall 2, fixed lower wall 3 and adjustable lower wall 4, wherein the fixed and adjustable lower wall 3 , 4 overlap at the lip portion, and the two side walls 2 are planes perpendicular to the lower wall surfaces 3, 4, generally trapezoidal in shape (or any quadrangle, subject to actual design requirements). The lower end line of the side wall 2 is generally a straight line inclined downward (the inclination angle is generally not more than 8 degrees). The adjustable lower wall 4 can be rotated on the line formed by the two ends of the lip (such as the lip is a straight line, that is, the lip is the axis), and when the lower walls 3 and 4 are planes, the maximum deflection position does not exceed the lower end line of the side wall 2 , when the lower wall surfaces 3 and 4 are curved surfaces, the deflection position of the side opposite to the lip does not exceed the straight line formed by connecting the lower end points of the two side walls 2 . When the movable lower wall 4 has no deflection, it coincides with the fixed lower wall 3 .

Outer fairing principle analysis of the present invention:

When the aircraft is in the state of accelerated flight, the movable lower wall has no deflection and coincides with the fixed lower wall. At this time, the frontal area of the aircraft is relatively minimum, and the inclination angle of the lower wall is relatively small, which is conducive to reducing the pressure difference resistance and shock wave resistance of the aircraft. . When the aircraft is in the cruising flight state, the movable lower wall deflects downward (clockwise) at a certain angle (the specific deflection value is determined by environmental conditions such as flight altitude, flight Mach number, and flight angle of attack). As the area increases, the movable lower wall can generate additional lift by compressing the incoming flow. Although the drag increases at the same time, the lift-to-drag ratio can be effectively improved, which is beneficial to the increase of the flight range of the aircraft.

Outer cowling practice effect test of the present invention:

The effectiveness of the solution of the present invention is tested in the following manner. Fig. 2 shows a two-dimensional configuration diagram of a hypersonic vehicle.

Numerical calculations are used to analyze this configuration. The calculation conditions are flight altitude 25km, flight Mach number 6, flight angle of attack 2 degrees, engine inlet adopts extrapolation conditions, and engine outlet is treated as a fixed wall (mainly to investigate the lift and drag of the aircraft) . The pressure distribution contour map obtained by numerical calculation is shown in Fig. 3.

Furthermore, on the basis of the configuration shown in Figure 2, the engine outer fairing is deflected. From the perspective of numerical calculation, deflecting the aforementioned movable lower wall is equivalent to deflecting the lower wall of the engine cowling (at hypersonic and Under the condition of small rotation angle, there is basically no flow in the gap between the two walls, so the gap between the movable lower wall and the trailing edge of the fixed lower wall can also be treated as the wall during calculation). After the movable lower wall is rotated clockwise by 2, 4, 6, and 8 degrees, the shapes of the obtained aircraft are shown in Figures 4a, 4b, 4c, and 4d, respectively.

Using the same numerical calculation conditions (including incoming flow conditions and calculation grid scale) to analyze the above four shapes, the calculation results are shown in Table 1-Table 3. (When the deflection angle in the table is 0, it means no deflection, which is the shape shown in Figure 2.

Table 1 Comparison of lift coefficients under different movable lower wall deflection angles

Table 2 Comparison of drag coefficients under different movable lower wall deflection angles

Table 3 Comparison of lift-to-drag ratio under different movable lower wall deflection angles

As can be seen from Table 2, when the deflection angle of the movable lower wall is 0 (no deflection, the movable lower wall and the fixed lower wall coincide), the drag coefficient of the aircraft is the smallest, which is conducive to the accelerated flight of the aircraft. With the increase of the inclination angle of the movable lower wall, it can be seen from Table 1-Table 3 that the lift coefficient, drag coefficient and lift-to-drag ratio of the aircraft all increase, but the increase of the lift coefficient is more obvious, so the lift-to-drag ratio increases significantly. The maximum is about 3 times that without deflection. Therefore, if cruise flight is carried out in this state, the flight range of the aircraft can be effectively increased. In addition, as the inclination angle of the movable lower wall gradually increases, the drag coefficient of the aircraft increases obviously. At this time, the lift-to-drag ratio of the aircraft increases slowly (continuing to increase the inclination may lead to a decrease in the lift-to-drag ratio). Therefore, the The rotation angle should not be too large, generally no more than 8 degrees, and the inclination angle of the lower edge of the two side walls should not exceed this angle, so as to minimize the frictional resistance brought by the side walls.

The present invention is only applicable to hypersonic vehicles powered by scramjet engines; the hypersonic vehicles involved in the present invention can adopt sharp leading edges or blunted leading edges, and the design and calculation methods are the same; for hypersonic missiles and other engines occupying For an aircraft with a relatively large size of the entire aircraft, the aerodynamic performance of the aircraft can be improved more effectively by adopting the present invention.

It should be pointed out that any modification made under the conception of the present invention according to the specific embodiments of the present invention shall not deviate from the spirit of the present invention and the scope of protection described in the claims.

Claims (8)

1. external cowling of scramjet engine, comprise sidewall and fixing lower wall surface, fixedly the both sides of lower wall surface are provided with sidewall, it is characterized in that, fixedly the turning axle that is provided with on its lip of the below of lower wall surface is hingedly connected with adjustable lower wall surface, this adjustable lower wall surface provides power around described turning axle deflection by driving mechanism, and limits adjustable lower wall surface inflection point by limitation locking mechanism.

2. external cowling of scramjet engine as claimed in claim 1 is characterized in that, the shape of described fixedly lower wall surface and adjustable lower wall surface is identical, and wherein, described fixedly lower wall surface and adjustable lower wall surface are plane or curved surface.

3. external cowling of scramjet engine as claimed in claim 2 is characterized in that, the extreme lower position of the bottom surface deflection of described adjustable lower wall surface is not less than the plane that sidewall lower edge that the both sides of described fixedly lower wall surface are provided with forms.

4. external cowling of scramjet engine as claimed in claim 1 is characterized in that, described adjustable lower wall surface is a curved surface, and the crowning of adjustable lower wall surface upwards is installed on the described turning axle.

5. external cowling of scramjet engine as claimed in claim 1 is characterized in that, described sidewall be shaped as quadrangular plan, the lower edge of this sidewall is to be the downward-sloping straight line of starting point with fixing lower wall surface lip, its angle of inclination is no more than 8 °.

6. external cowling of scramjet engine as claimed in claim 1, it is characterized in that, described driving mechanism is the aft mounted bullet drawing device of described fixedly lower wall surface, this bullet drawing device provides power to described adjustable lower wall surface, makes adjustable lower wall surface to the base deflection of described sidewall or to the deflection of described fixedly lower wall surface direction.

7. external cowling of scramjet engine as claimed in claim 6 is characterized in that, described bullet loads and is changed to strong elastic device or small blasting drive unit.

8. external cowling of scramjet engine as claimed in claim 1, it is characterized in that, described limitation locking mechanism comprises guide rail that is provided with on the sidewall and the sliding guide that is slidingly matched with guide rail, this guide rail extends and terminates in place, sidewall base to the base of described sidewall from described fixedly lower wall surface, sliding guide is arranged on the described adjustable lower wall surface, and be erected in the described guide rail on the two side, the two ends when the place that sliding guide moves to guide rail fix at guide rail in the groove at place.

Images