A fixed-wing supersonic aircraft with reduced transonic drag

Abstract

The present application belongs to the field of aircraft design, and particularly relates to a fixed-wing supersonic aircraft with reduced transonic drag. The positions of the wings on both sides of the aircraft along the heading direction are different, which can optimize the cross-sectional area distribution of the whole aircraft, reduce the adverse effects of the shock waves on the left and right wings in the transonic stage, and increase the favorable effects, thereby reducing the transonic drag of the aircraft. Due to the reduction of transonic drag, the aircraft's transonic residual thrust can be increased, the aircraft's acceleration can be improved, and the aircraft's speed maneuverability can be improved; the transonic acceleration fuel consumption can be reduced, and the aircraft's transonic flight range can be increased.

Description

Technical Field

[0001] The present application belongs to the field of aircraft design, and in particular to a fixed-wing supersonic aircraft with reduced transonic drag. Background Art

[0002] by Figure 3 The wing-body assembly shown in the figure is used as an example for explanation. The left and right wings of a traditional supersonic aircraft are symmetrical in configuration, and the left and right wings are at the same position in the front and rear direction of the fuselage. The peak cross-sectional area of ​​the wing is exactly the same in the front and rear direction of the fuselage. After the cross-sectional areas of the fuselage and the left and right wings are superimposed, the peak cross-sectional area of ​​the entire aircraft is large, such as Figure 4 As shown. According to the transonic area law, the transonic wave resistance of the aircraft is large. From the perspective of flow mechanism, the windward surface of the leading edge of the left wing (such as point A) generates positive pressure under the action of the airflow. The positive pressure at this point propagates backward along the Mach cone BAC, not only generating resistance at the leading edge of the wing on this side, but also propagating to the leading edge of the right wing, thereby causing a further increase in resistance; the situation is similar for point D on the leading edge of the right wing. Similarly, for the leeward surface of the trailing edge of the wing (such as point G), negative pressure is generated at this point under the action of the airflow. The negative pressure at this point propagates backward along the Mach cone HGC, not only generating resistance at the trailing edge of the wing on this side, but also propagating to the trailing edge of the right wing, thereby causing a further increase in resistance; the situation is similar for point I on the trailing edge of the right wing. The above adverse interference between the left and right wings leads to increased resistance, reduced transonic residual thrust of the aircraft, weakened the transonic acceleration performance of the aircraft, increased transonic acceleration fuel consumption, reduced the aircraft's transonic speed maneuverability, and was not conducive to improving the aircraft's maneuverability and increasing the range. Summary of the invention

[0003] In order to solve the above problems, the present application provides a fixed-wing supersonic aircraft with reduced transonic drag, including: the distances between the wings on both sides and the front end of the aircraft are different.

[0004] Preferably, the leading edge of the wing is swept backwards and the trailing edge of the wing is swept forwards.

[0005] Preferably, the maximum cross-sectional areas of the wings on both sides are located at different positions in the heading direction.

[0006] Preferably, the wing is a fixed wing.

[0007] Preferably, the wings on both sides have the same shape.

[0008] Preferably, the sweep angle of the wing leading edge is smaller than the cone angle of the Mach cone generated by the wing leading edge.

[0009] Preferably, the position difference of the two side wings along the heading direction of the aircraft satisfies that the positive pressure area generated by the leading edge of one wing propagates along the Mach cone and falls into the negative pressure area generated by the trailing edge of the other wing.

[0010] Preferably, the load-bearing beams of the wings on both sides are symmetrically distributed along the axis of the aircraft.

[0011] Preferably, the wing is a major lift contributing component of the aircraft.

[0012] Preferably, the ratio of the absolute value of the position difference between the wings on both sides along the heading direction of the aircraft to the length of the aircraft along the heading direction is in the range of 0.001 to 0.600.

[0013] The advantages of the present application include: compared with aircraft with symmetrical left and right wings, the present invention adopts asymmetric configuration technology of the front and rear positions of the left and right wings, which can optimize the cross-sectional area distribution of the whole aircraft, reduce the adverse effects of the shock waves of the left and right wings in the transonic stage, increase the favorable effects, and thus reduce the transonic drag of the aircraft. Due to the reduction of transonic drag, the transonic residual thrust of the aircraft can be increased, the acceleration of the aircraft can be improved, and the speed maneuverability of the aircraft can be improved; the fuel consumption of transonic acceleration can be reduced, and the transonic flight range of the aircraft can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a fixed-wing supersonic aircraft for reducing transonic drag according to a preferred embodiment of the present application.

[0015] Figure 2 It is a schematic diagram of the cross-sectional area of ​​the wing-body assembly with asymmetrical front and rear positions of the left and right wings.

[0016] Figure 3 It is a schematic diagram of a traditional wing-body assembly with symmetrical front and rear positions of the left and right wings.

[0017] Figure 4 It is a schematic diagram of the cross-sectional area of ​​the wing-body assembly of the traditional left and right symmetrical wing configuration.

[0018] Figure 5 It is a comparison chart of the total cross-sectional area distribution of a wing-body assembly with a symmetrical configuration of the left and right wings and a wing-body assembly with an asymmetrical configuration of the left and right wings.

[0019] Figure 6 It is the curve of drag coefficient changing with Mach number for a wing-body combination with a symmetrical configuration of left and right wings in front and back positions and a wing-body combination with an asymmetrical configuration of left and right wings in front and back positions at an altitude of 9km and an angle of attack of 0 degrees. DETAILED DESCRIPTION

[0020] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be further described in detail in detail and in detail in conjunction with the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0021] The present application provides a fixed-wing supersonic aircraft with reduced transonic drag, in which the left and right wings are in an asymmetric state, which is mainly reflected in the different positions of the wings on both sides along the heading direction of the aircraft, that is, the distances between the left and right wings and the nose vertex are different, and they are in a front-rear state. Including but not limited to: the left wing is forward and the right wing is backward, the left wing is backward and the right wing is forward; similarly, the asymmetric configuration of the front and rear positions of the left and right horizontal tails, the left and right engine compartments, the left and right canards, and the left and right vertical tails (if it is a double vertical tail aircraft) can also achieve a similar effect of asymmetric front and rear positions of the left and right wings.

[0022] Wherein, the shapes of the wings on both sides are the same, the wings are fixed wings, the sweep angle of the leading edge of the wings is less than the cone angle of the Mach cone generated by the leading edge of the wings, the load-bearing beams of the wings on both sides are symmetrically distributed along the axis of the aircraft, and the wings are the main lift contribution components of the aircraft. Preferably, the ratio of the absolute value of the position difference of the wings on both sides along the heading direction of the aircraft to the length of the aircraft along the heading direction is in the range of: 0.001 to 0.6.

[0023] The reason why the wings on both sides of this application are located at different positions along the heading direction of the aircraft is:

[0024] 1. Make the maximum cross-sectional area of ​​the wings on both sides in different heading directions.

[0025] 2. The positive pressure generated by the leading edge of one wing propagates along the Mach cone and falls into the negative pressure area generated by the trailing edge of the other wing.

[0026] The following is a detailed description with reference to the accompanying drawings:

[0027] The following is Figure 1 The wing-body assembly with a left wing at the rear and a right wing at the front is shown as an example to illustrate the principle of reducing transonic drag. Figure 3 The wing-body assembly with symmetrical left and right wings is shown. Figure 1 In the case shown, the right wing of the wing-body assembly moves forward 1m, the left wing moves backward 1m, and the rest is exactly the same.

[0028] From the perspective of cross-sectional area distribution: Figure 1As shown in the figure, since the left wing is at the rear and the right wing is at the front, the cross-sectional areas of the left and right wings are at different positions in the front and rear directions of the fuselage, thus avoiding the superposition of the peak cross-sectional areas of the wings. Figure 2 As shown in the figure. The asymmetric configuration of the front and rear positions of the left and right wings effectively reduces the maximum cross-sectional area of ​​the entire aircraft and improves the cross-sectional area distribution of the entire aircraft, as shown in the figure. Figure 5 According to the principle of transonic area law, by reducing the maximum cross-sectional area and improving the cross-sectional area distribution, the aircraft's transonic wave resistance can be effectively reduced.

[0029] From the perspective of flow mechanism: Figure 3 The wing shown has a bilaterally symmetrical configuration. Figure 1 In the case shown, the right wing moves forward and the left wing moves backward. The windward surface of the leading edge of the left wing (such as point A) generates positive pressure under the action of the airflow, and the positive pressure at this point propagates backward along the Mach cone BAC. Due to the asymmetric front-to-back position of the left and right wings, the positive pressure at point A propagates to the trailing edge of the right wing, generating forward thrust at the trailing edge of the right wing. For the leeward surface of the trailing edge of the left wing (such as point G), negative pressure is generated at this point under the action of the airflow. The negative pressure at this point propagates backward along the Mach cone HGC. Due to the asymmetric front-to-back position of the left and right wings, the negative pressure at point G can no longer propagate to the trailing edge of the right wing, thus avoiding the interference drag caused by the negative pressure at the trailing edge of the left wing propagating to the trailing edge of the right wing in the symmetrical configuration of the left and right wings.

[0030] pass Figure 3 The conventional left and right wings have a symmetrical front and rear configuration of the wing-body assembly shown in FIG. Figure 1 The comparison of the wing-body assembly with asymmetric configuration of the front and rear positions of the left and right wings shown illustrates the role of the application.

[0031] Figure 3 The main parameters of the wing-body assembly with a conventional left and right wing symmetrically positioned in front and back are as follows:

[0032] Fuselage length: 18m;

[0033] Maximum fuselage diameter: 1.2m;

[0034] Theoretical wing area: S=36㎡;

[0035] Wing leading edge sweep angle: 38°;

[0036] Trailing edge sweep angle: 20°;

[0037] Wing span: L = 9m;

[0038] Relative thickness of wing tip airfoil: 5%;

[0039] Relative thickness of airfoil at exposed root chord: 4.5%;

[0040] The distance between the theoretical root chord of the wing and the nose vertex: 6m;

[0041] Through numerical simulation, we obtained Figure 3 The drag coefficient of the conventional wing-body assembly with symmetrical front and rear left and right wings at an altitude of 9 km and an angle of attack of 0° is as follows: Figure 6 In the transonic range, the zero angle of attack drag coefficients at Mach numbers 1.0 and 1.1 are 0.0756 and 0.07289 respectively.

[0042] If the asymmetric configuration technology of the left and right wings for reducing transonic drag is adopted, Figure 3 Based on the conventional wing-body assembly with symmetrical front and rear positions of the left and right wings, the right wing is moved back 1m and the left wing is moved forward 1m, while the other parameters remain unchanged, forming Figure 1 The left and right wings are shown in an asymmetrical configuration of the wing-body assembly. The main parameters are as follows:

[0043] Fuselage length: 18m;

[0044] Maximum fuselage diameter: 1.2m;

[0045] Theoretical wing area: S=36㎡;

[0046] Wing leading edge sweep angle: 38°;

[0047] Trailing edge sweep angle: 20°;

[0048] Wing span: L = 9m;

[0049] Relative thickness of wing tip airfoil: 5%;

[0050] Relative thickness of airfoil at exposed root chord: 4.5%;

[0051] The distance between the theoretical root chord of the right wing and the nose vertex: 5m;

[0052] The distance between the theoretical root chord of the right wing and the nose vertex: 7m;

[0053] Through the same numerical simulation method, we obtained Figure 1 The drag coefficient of the wing-body assembly with asymmetric front and rear positions of the left and right wings at an altitude of 9 km and an angle of attack of 0° is as follows: Figure 6 In the transonic range, the zero angle of attack drag coefficients at Mach numbers of 1.0 and 1.1 are reduced to 0.06672 and 0.06974, respectively, and the zero angle of attack drag coefficients are reduced by 11.7% and 4.32%, respectively.

[0054] By comparing the transonic zero angle of attack drag coefficients of the wing-body assembly with a symmetrical configuration of the left and right wings in front and back positions and the wing-body assembly with an asymmetrical configuration of the left and right wings in front and back positions, it can be seen that the present invention effectively reduces the maximum cross-sectional area of ​​the entire aircraft and reduces the transonic wave drag, thereby increasing the transonic residual thrust and improving the transonic maneuverability of the aircraft.

[0055] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A fixed-wing supersonic aircraft with reduced transonic drag, characterized in that: include: The distances between the wings on both sides and the front end of the aircraft are different. The leading edge of the wing is swept back, and the trailing edge of the wing is swept forward. The sweep angle of the leading edge of the wing is smaller than the cone angle of the Mach cone generated by the leading edge of the wing. The position difference between the wings on both sides along the heading direction of the aircraft satisfies: the positive pressure generated by the leading edge of one wing propagates along the Mach cone and falls into the negative pressure area generated by the trailing edge of the other wing; the load-bearing beams of the wings on both sides are symmetrically distributed along the axis of the aircraft.

2. The fixed-wing supersonic aircraft with reduced transonic drag according to claim 1, characterized in that: The maximum cross-sectional area of ​​the wings on both sides is located at different locations in the heading direction.

3. The fixed-wing supersonic aircraft with reduced transonic drag according to claim 1, characterized in that: The wing is a fixed wing.

4. The fixed-wing supersonic aircraft with reduced transonic drag according to claim 1, characterized in that: The wings on both sides have the same shape.

5. The fixed-wing supersonic aircraft with reduced transonic drag according to claim 1, characterized in that: The ratio of the absolute value of the position difference between the wings on both sides along the heading direction of the aircraft to the length of the aircraft along the heading direction is in the range of 0.001 to 0.6.

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