Parallel combination and double-knife pushing and punching device

Abstract

The application belongs to the technical field of aircraft design, and relates to a parallel combination body and a double-knife push-pull device. The double-knife push-pull device is arranged in a carrier bracket and can be driven by a driving device in the carrier bracket to extend out of the upper surface of the carrier bracket, so as to lift an aircraft located above the carrier bracket and make the aircraft separate from the carrier bracket. Left and right sides of the carrier bracket are respectively connected with one carrier engine. The double-knife push-pull device comprises two identical push-pull knives. The outer contour of each push-pull knife along a section perpendicular to the extending direction of the push-pull knife is enclosed by an inner side line and an outer side line. The inner side refers to the opposite side of the two push-pull knives, and the inner side lines of the two push-pull knives are straight lines and are parallel to each other. The outer side line comprises a middle horizontal line, and front end arc lines and rear end arc lines at two ends for being connected with the inner side lines. The application realizes safe separation of the parallel combination body in a high-speed flight environment.

Description

Technical Field

[0001] This application belongs to the field of aircraft design technology, and specifically relates to a parallel assembly and a double-blade thrust device. Background Technology

[0002] High Mach number ramjet-powered aircraft typically employ air-launched or ground-launched rockets to propel them to high altitudes and Mach numbers, establishing stable operating conditions for the ramjet engine. The rocket acts as the launch vehicle, and the aircraft as the carried vehicle, forming a combined system. Based on the positional relationship between the carried aircraft and the launch vehicle, combined systems can be categorized into tandem and parallel systems. A tandem system usually refers to a design where the launch vehicle and the carried vehicle are connected in series, while a parallel system usually refers to a design where the launch vehicle and the carried vehicle are connected vertically. In a parallel system, the distance between the wings of the carried aircraft and the center of gravity of the combined system is short, facilitating focal point matching of the combined system's center of gravity. This is particularly important for the launch design of high Mach number aircraft with large lifting surfaces.

[0003] The launch vehicle and the carrier vehicle are combined in parallel. The launch vehicle and the carrier vehicle need to separate at a high Mach number, usually Mach number Ma is greater than 3.0. The shorter the separation time, the higher the safety. Generally, it is required that the normal distance between the launch vehicle and the carrier vehicle be greater than 0.15 times the length of the launch vehicle within 0.5 seconds. That is, the aircraft should separate upwards and move to outside the Mach cone angle of the launch vehicle within 0.5 seconds.

[0004] Therefore, an auxiliary separation device, namely a thrust device, is usually set between the carried aircraft and the carrier. This device can provide the carried aircraft with an initial normal separation velocity, helping it to move to the predetermined safe area in a shorter time, and ultimately achieve the safe separation of the parallel assembly at high Mach numbers.

[0005] Figure 1 The diagram shows a parallel twin-fuselage assembly. The upper part is the aircraft being carried, composed of conventional wings, fuselage, and vertical tail components. The lower part consists of two rocket launchers, each composed of launcher engines, main wings, launcher brackets, thrusters, and auxiliary power units. The lower end of the launcher bracket is fixed to the launcher, and the upper end is fixed to the aircraft being carried via explosive bolts. The thrusters retract into the launcher brackets. Figures 2-4 This demonstrates the separation process of the parallel twin-plane assembly. During separation, the fixed connection between the aircraft and the carrier bracket is released under the action of explosive bolts. Simultaneously, the thrust device ejects from the carrier bracket, applying an upward normal force to the aircraft. This function adds an initial normal velocity to the carried aircraft, supporting its upward acceleration. The lower end of the thrust device is fixedly connected to the motion mechanism inside the bracket, while the upper end is attached to the lower surface of the aircraft but not fixedly connected, only transmitting the normal force. Figure 4After the thrust device reaches its limit position, the aircraft continues to move upward under the action of aerodynamic lift, ultimately achieving the safe separation of the carried aircraft from the carrier.

[0006] Regarding the configuration design of the thruster, conventional high-speed aircraft (Ma < 2.0) typically employ single-blade or double-blade thrusters, as detailed below. Figure 5 and Figure 7 .

[0007] Figure 5 The image shown is a top-view projection of a single-blade thruster. It can be seen that the single-blade thruster is characterized by a symmetrical airfoil with zero relative camber. The relative thickness of the airfoil is generally between 4% and 6%. Too low a relative thickness will result in insufficient load-bearing capacity, while too high a relative thickness will lead to excessive weight and strong separation interference. The total length of the single-blade thruster can be customized according to the structure of the aircraft being launched. When this single-blade thruster is applied to the separation of high-speed parallel assemblies at Mach numbers above 3.0, the following problems arise:

[0008] 1) High-speed aircraft typically employ a large sweep and low aspect ratio configuration, resulting in inferior roll control compared to aircraft with a large aspect ratio configuration. They are also more sensitive to roll moment during assembly separation. Figure 6 For example, the single-blade thrust device is prone to being installed off-center from the plane of symmetry P. The additional rolling moment M generated at the center of gravity Q is about 10% of the efficiency of the roll control surface. If the yaw gust at the moment of separation is superimposed, it is particularly easy to cause insufficient roll control capability, which will have an adverse effect on the separation of the assembly.

[0009] 2) The high-speed aircraft being transported are generally smaller in size and tonnage. Compared with the double-blade type, the stress at the thrust point is more concentrated when using a single-blade type thrust device, which will lead to an increase in the structural weight coefficient of the aircraft being transported during the design process.

[0010] In summary, the single-blade push-impact device configuration is not suitable for high Mach number separation in parallel assemblies.

[0011] Figure 7 The diagram shows a conventional double-blade thruster, consisting of two identical thrust blades. The top-view projection characteristics of either thrust blade are similar to those of a single-blade type, exhibiting a symmetrical airfoil with a relative thickness typically between 2% and 4%. Both thrust blades bear the same thrust force. The spacing between the two thrust blades initially narrows in the downstream direction, then becomes uniformly straight, and finally widens. Applying this thruster to the separation of high-speed parallel assemblies at Mach numbers above 3.0 will lead to the following problems:

[0012] When supersonic airflow passes between the two blades of the aforementioned double-blade thruster, a flow "congestion" effect occurs. According to the basic principles of fluid mechanics, supersonic airflow decelerates and experiences pressure increases in the contraction section, and accelerates and experiences pressure decreases in the expansion section. Fluid mechanics simulations revealed that the inlet section of a conventional symmetrical airfoil double-blade thruster is a high-pressure zone, while the outlet section is a low-pressure zone. This interferes with the carried aircraft. The area where the carried aircraft contacts the thruster is a high-pressure zone in the front section and a low-pressure zone in the rear section, resulting in a large additional pitching moment. This can easily cause pitching divergence and separation failure during high-speed separation of the combined aircraft. Summary of the Invention

[0013] To address the aforementioned issues, this application provides a parallel assembly and a double-blade pusher device to improve the separation success rate of the parallel assembly.

[0014] The first aspect of this application provides a double-blade thrust device, which is disposed in a carrier bracket and can be driven by a drive device in the carrier bracket to extend out of the upper surface of the carrier bracket, so as to lift the aircraft located above the carrier bracket and detach it from the carrier bracket. The left and right sides of the carrier bracket are respectively connected to a carrier engine.

[0015] The double-blade punching device includes two identical punching blades. Each punching blade is formed by an inner line and an outer line along its cross-sectional outer contour perpendicular to its extension direction. The inner side refers to the side opposite to the two punching blades. The inner lines of the two punching blades are straight lines and parallel to each other. The outer lines include a horizontal line in the middle and front and rear arcs at both ends for connecting with the inner lines.

[0016] Preferably, the relative curvature of each push punch is 2% to 4%.

[0017] Preferably, the relative curvature of each push punch is 3%.

[0018] Preferably, the projection distance of the front end arc on the inner line is 0.4L, and the projection distance of the rear end arc on the inner line is 0.15L, where L is the length of the inner line.

[0019] The second aspect of this application provides a parallel assembly including two carrier engines and an aircraft carried by the carrier engines. The two carrier engines are arranged side by side and connected by a carrier bracket. The carrier bracket has a receiving groove in the middle, and a double-blade thrust device as described above is provided in the receiving groove. The double-blade thrust device can rise from the receiving groove when the carrier engines and the aircraft separate at high speed to lift the aircraft located above the carrier bracket.

[0020] Preferably, the conditions for high-speed separation are that the flight Mach number of the parallel assembly is greater than 3 and the flight angle of attack of the parallel assembly is 4°.

[0021] This application reduces the aerodynamic interference between the auxiliary separation thrust device and the launch vehicle, and achieves safe separation of the parallel assembly in a high-speed flight environment. Attached Figure Description

[0022] Figure 1 This is a top view of a two-body parallel composite structure.

[0023] Figure 2 yes Figure 1 The cross-sectional view of the two-body parallel assembly AA shown.

[0024] Figure 3 This is a schematic diagram of the separation process of a two-body parallel assembly.

[0025] Figure 4 This is a schematic diagram of the structure when the two parallel bodies are completely separated.

[0026] Figure 5 This is a top view of a single-blade pusher device.

[0027] Figure 6 yes Figure 5 The diagram shows an eccentric thrusting action of a single-blade type thrusting device.

[0028] Figure 7 This is a top view of a double-blade pusher device.

[0029] Figure 8 This is a top view of a preferred embodiment of the double-blade punching device of this application.

[0030] Figure 9 This is a schematic diagram comparing the pitching moments of the aircraft carried by the combined system of this application and existing combined systems during the initial separation phase.

[0031] Among them, 1-double blade thrust device, 2-carrier bracket, 3-aircraft, 4-carrier engine, 5-main wing, 6-thrust device, 11-inner line, 12-outer line. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0033] The first aspect of this application provides a double-blade thrusting device for assisting in the separation of parallel assemblies at high speeds. (See reference...) Figure 1 and Figure 3 The existing thrust device 6 is installed inside the carrier bracket 2 and can be driven by the drive device inside the carrier bracket 2 to extend out of the upper surface of the carrier bracket 2, so as to lift the aircraft 3 located above the carrier bracket 2 and detach it from the carrier bracket 2. The left and right sides of the carrier bracket 2 are respectively connected to a carrier engine 4.

[0034] This application configures the punching device 6 as a double-blade punching device, and the structure of the double-blade punching device 1 is as follows: Figure 8 As shown, it includes two identical pusher blades. The outer contour of each pusher blade along its cross-section perpendicular to its extension direction is formed by an inner line 11 and an outer line 12. The inner side refers to the side of the two pusher blades facing each other. The inner lines 11 of the two pusher blades are straight lines and parallel to each other. The outer line 12 includes a horizontal line in the middle, and front and rear arcs located at both ends for connecting with the inner lines 11.

[0035] Compared to Figure 7The pusher device shown in this application has two pusher blades. The length L, height H, relative thickness D, and spacing S of the pusher blades remain basically unchanged to ensure that the load-bearing capacity remains unchanged. The two pusher blades are arranged side by side in the flow direction to form a double-blade pusher device. The main difference is in the cross-sectional shape. The top view projection of the pusher blades in this application is an airfoil shape, which makes the inner side of the double-blade pusher device a straight line, increases the airfoil camber, and makes the airfoil mid-curve curve outward. In some optional embodiments, the relative camber of each pusher blade is 2% to 4%. The relative camber refers to the ratio of the maximum camber f to the chord length c. The maximum camber f is the maximum vertical distance from the mid-curve line to the airfoil chord line (the straight line connecting the leading edge and the trailing edge). The mid-curve line is the line connecting the midpoints of all vertical distances between the upper and lower surfaces of the airfoil, that is, the curve formed by the midpoints of the upper and lower surfaces in the vertical direction. The chord length c is the length of the airfoil chord line, that is, the straight-line distance from the leading edge to the trailing edge of the airfoil.

[0036] In some alternative implementations, the relative curvature of each push punch is 3%.

[0037] In some alternative embodiments, the projection distance of the front end arc on the inner line 11 is 0.4L, and the projection distance of the rear end arc on the inner line 11 is 0.15L, where L is the length of the inner line 11.

[0038] The thrust configuration provided in this application has a flat inner side, which allows for more uniform airflow. The high-pressure zone at the inlet is small, and the separation process causes less aerodynamic interference to the lower surface of the aircraft being transported. Figure 9 The pitching moment curves during the separation process of the launch vehicle and the carried aircraft are given. The horizontal axis represents the angle of attack of the combined aircraft, and the vertical axis represents the pitching moment. Figure 9 It can be seen that:

[0039] 1) In the range of angle of attack of the combined body from -4° to +12°, compared with the configuration using a conventional thrust device, the pitching moment of the aircraft carried by this application is significantly reduced, which is closer to the configuration without a thrust device, indicating that the interference pitching moment generated by this application on the aircraft is smaller.

[0040] 2) At the moment of separation, the typical angle of attack of the combined vehicle is 4°. The pitch moment disturbance increment of the carried aircraft is reduced from +0.01175 to +0.00363 (a positive value indicates pitching up). This application reduces the pitching disturbance moment coefficient experienced by the carried aircraft by 69.1%.

[0041] 3) At the moment of separation, the typical angle of attack of the combined body is 4°. The pitch moment of the aircraft carried by this application is close to 0, making it easier to trim in terms of aircraft attitude control.

[0042] In summary, the inner straight airfoil-shaped double-blade thrust device configuration for high-speed separation of the parallel assembly provided in this application is more conducive to the realization of high-speed separation of the assembly.

[0043] The second aspect of this application provides a parallel assembly including two carrier engines 4 and an aircraft 3 carried by the carrier engines 4. The two carrier engines 4 are arranged side by side and connected by a carrier bracket 2. The carrier bracket 2 has a receiving groove in the middle. The receiving groove is provided with a double-blade thrust device 1 as described above. The double-blade thrust device 1 can rise from the receiving groove when the carrier engine 4 and the aircraft 3 separate at high speed to lift the aircraft 3 located above the carrier bracket 2.

[0044] In some alternative implementations, the high-speed separation condition is that the flight Mach number of the parallel assembly is greater than 3 and the flight angle of attack of the parallel assembly is 4°.

[0045] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A double-blade punching device, characterized in that, The double-blade thrust device (1) is installed inside the carrier bracket (2) and can be driven by the drive device inside the carrier bracket (2) to extend out of the upper surface of the carrier bracket (2) to lift the aircraft (3) located above the carrier bracket (2) and detach it from the carrier bracket (2). The left and right sides of the carrier bracket (2) are respectively connected to a carrier engine (4). The double-blade pusher device (1) includes two identical pusher blades. Each pusher blade is formed by an inner line (11) and an outer line (12) along its cross-sectional outer contour perpendicular to its extension direction. The inner side refers to the side opposite to the two pusher blades. The inner lines (11) of the two pusher blades are straight lines and parallel to each other. The outer line (12) includes a horizontal line in the middle and front and rear arcs at both ends for connecting with the inner lines (11).

2. The double-blade punching device as described in claim 1, characterized in that, The relative curvature of each pusher is 2% to 4%.

3. The double-blade punching device as described in claim 2, characterized in that, The relative curvature of each pusher is 3%.

4. The double-blade punching device as described in claim 1, characterized in that, The projection distance of the front end arc on the inner line (11) is 0.4L, and the projection distance of the rear end arc on the inner line (11) is 0.15L, where L is the length of the inner line (11).

5. A parallel assembly, characterized in that, It includes two carrier engines (4) and an aircraft (3) carried by the carrier engines (4). The two carrier engines (4) are arranged side by side and connected by a carrier bracket (2). The carrier bracket (2) has a receiving groove in the middle. The receiving groove is provided with a double-blade thrust device (1) as described in claim 1. The double-blade thrust device (1) can rise from the receiving groove when the carrier engine (4) and the aircraft (3) separate at high speed to lift the aircraft (3) located above the carrier bracket (2).

6. The parallel assembly as described in claim 5, characterized in that, The conditions for high-speed separation are that the flight Mach number of the parallel assembly is greater than 3 and the flight angle of attack of the parallel assembly is 4°.

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