An integrated frame for parallel sharing of multiple engines

Abstract

The present invention belongs to a kind of frame. To solve the technical problem that the load-bearing structure of existing high-speed aircraft is difficult to simultaneously meet the functions of high strength, good environmental stability, load-bearing, propellant transportation, etc., an integrated frame with multiple engines in parallel and shared is provided. On the frame, a fuel tank flange, an oxidizer tank flange, a fuel outlet, an oxidizer outlet, a fuel flow channel, an oxidizer flow channel, and a gas flow channel are integrated. The back of the main support can be connected to three engines and the attitude control system to form an integrated frame. The overall structure is compact in volume and lighter in mass, which is beneficial to the lightweight and miniaturization development of the engines. At the same time, the load-bearing performance of the frame structure is ensured. In addition, on the premise of meeting the design requirements of the frame, the manufacturing cost of the product is optimized.

Description

Technical Field

[0001] The present invention belongs to a force transmission frame, and particularly relates to an integrated frame shared by multiple engines in parallel. Background Art

[0002] With the development of high-performance high-speed aircraft, aircraft design requires highly integrated design. The traditional high-speed aircraft structure adopts a design method in which the load-bearing structure and the propellant delivery structure are separated. With the increase of flight speed and flight time, the single-function structure design scheme will pay a relatively high mass cost and it is difficult to meet the requirements of aircraft performance improvement and higher operating environment. Therefore, with the development of high-speed aircraft structures from single function to multi-function integration, the multi-function structure should not only have the characteristics of high strength and good environmental stability, but also take into account functions such as load-bearing and propellant delivery to achieve lightweight and efficient structure design. However, the existing load-bearing structures of high-speed aircraft are difficult to meet these requirements. Summary of the Invention

[0003] In order to solve the technical problem that the existing load-bearing structures of high-speed aircraft are difficult to simultaneously meet the functions of high strength, good environmental stability, load-bearing, propellant delivery, etc., the present invention provides an integrated frame shared by multiple engines in parallel.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An integrated frame shared by multiple engines in parallel, characterized in that it includes a main support and a frame. The main support is located inside the frame, and the main support and the frame are connected by a plurality of mounting supports;

[0006] One fuel tank flange and two oxidizer tank flanges are provided on the front surface of the main support, which are respectively used to connect the fuel tank and the oxidizer tank; three fuel outlets and three oxidizer outlets are provided on the front surface of the main support, which are respectively used to connect the fuel inlets of three engines and the oxidizer inlets of three engines. The fuel tank flange and the three fuel outlets are respectively connected by three independent fuel flow channels, and the two oxidizer tank flanges and the three oxidizer outlets are respectively connected by oxidizer flow channels. The fuel flow channels and the oxidizer flow channels are both located inside the main support;

[0007] The back surface of the main support is used to connect three engines. An air port is provided on the back surface of the main support, and the air port is connected to an external gas cylinder. The air port is respectively connected to six pneumatic valves for controlling the three fuel outlets and the three oxidizer outlets through a plurality of gas flow channels;

[0008] Two attitude control mounting plates are provided on the back surface of the main support, which are used to connect two attitude control systems.

[0009] Further, the frame is a pentagon, and each corner is a rounded structure.

[0010] Further, the five sides of the frame are respectively denoted as the first side, the second side, the third side, the fourth side, and the fifth side. Among them, the first side and the second side are adjacent and have equal side lengths; the third side and the fourth side are opposite and have equal side lengths; the first side is adjacent to the third side, the second side is adjacent to the fourth side; the side length of the fifth side is greater than the other side lengths, and both ends of the fifth side are respectively connected to the third side and the fourth side;

[0011] There are ten mounting supports, and the connection points of the ten mounting supports with the frame are distributed as follows: there are two connection points on both the first side and the second side, one connection point on both the third side and the fourth side, and four connection points on the fifth side;

[0012] The mounting supports are of a bent structure from the main support to the frame.

[0013] Further, the end of the mounting support close to the frame is a round-to-square structure, and the round-to-square part is a filleted structure.

[0014] Further, the oxidizer flow channel includes two first oxidizer flow channels and a second oxidizer flow channel;

[0015] The two oxidizer tank flanges are respectively connected to the second oxidizer flow channel through the two first oxidizer flow channels, and the first oxidizer flow channel is in the shape of an arc with a central angle of 135°;

[0016] The second oxidizer flow channel is respectively connected to three oxidizer outlets.

[0017] Further, the fuel tank flange is located at the uppermost end of the main support, the three oxidizer outlets and the two oxidizer tank flanges are all located at the lowermost part of the main support and are on the same horizontal line, and the two oxidizer tank flanges are respectively located outside both ends of the three oxidizer outlets.

[0018] Further, three thrust chamber flanges are provided on the back of the main support for connecting three engines;

[0019] A plurality of reinforcing ribs are circumferentially arranged on the side surface of the thrust chamber flange, and the structure between adjacent reinforcing ribs is a hollow structure.

[0020] Further, the three thrust chamber flanges are located in the middle of the main support and are on the same straight line;

[0021] One attitude control mounting plate is located between the middle thrust chamber flange and the fuel tank flange, and the other attitude control mounting plate is located between the middle thrust chamber flange and the second oxidizer flow channel.

[0022] Further, the materials of the main support, the frame, and the mounting supports are all titanium alloy.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention proposes an integrated frame for parallel sharing of multiple engines, which integrates fuel tank flange, oxidizer tank flange, fuel outlet, oxidizer outlet, fuel flow channel, oxidizer flow channel, and gas flow channel on the frame. The back of the main support can be connected to three engines and the attitude control system to form an integrated frame. The overall structure is compact in volume and lighter in weight, which is conducive to the lightweight and miniaturization development of the engine. At the same time, the load-bearing performance of the frame structure is ensured. In addition, on the premise of meeting the design requirements of the frame, the manufacturing cost of the product is optimized.

[0025] 2. The frame of the present invention is designed as a pentagon with rounded corners at the edges and corners, making the structure more compact and conducive to eliminating stress concentration.

[0026] 3. Through the rational layout of each flow channel and interface, the present invention further optimizes the load-bearing performance and layout rationality of the entire frame. Verified by mechanical analysis, it can excellently meet the load-bearing performance and can significantly reduce weight and cost.

[0027] 4. The side of the thrust chamber flange of the present invention is provided with reinforcing ribs and the structure between adjacent reinforcing ribs is a hollow structure, which can ensure the structural strength while reducing weight.

[0028] 5. In the present invention, the main components are all made of titanium alloy material, making the overall quality of the frame lighter and the mechanical properties better. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of an embodiment of an integrated frame for parallel sharing of multiple engines of the present invention;

[0030] Figure 2 is a schematic diagram of the mounting support in the embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of the oxidizer tank flange in the embodiment of the present invention;

[0032] Figure 4 is a schematic diagram of the flow channel in the embodiment of the present invention;

[0033] Figure 5 is a schematic diagram of the gas flow channel in the embodiment of the present invention;

[0034] Figure 6 is a schematic diagram of the attitude control mounting plate in the embodiment of the present invention;

[0035] Figure 7 is a schematic diagram of the thrust chamber flange in the embodiment of the present invention;

[0036] Wherein: 1 - main support, 2 - frame, 3 - mounting support, 4 - first side, 5 - second side, 6 - third side, 7 - fourth side, 8 - fifth side, 9 - adapter, 10 - fuel tank flange, 11 - oxidizer tank flange, 12 - attitude control mounting plate, 13 - fuel flow channel, 14 - first oxidizer flow channel, 15 - gas flow channel, 16 - fuel outlet, 17 - oxidizer outlet, 18 - second oxidizer flow channel, 19 - gas port, 20 - thrust chamber flange. Detailed implementation manners

[0037] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Components of the embodiments of the present invention described and illustrated herein can generally be arranged and designed in a variety of different configurations.

[0038] As Figure 1 shown, the present invention provides an integrated frame for parallel sharing of multiple engines, and the overall dimensions can be 950mm * 570mm * 110mm. The following is a specific embodiment of the present invention. According to the results of integrated structure topology optimization and in combination with the connection form between the integrated structure and the overall cabin structure, the integrated frame of the present invention includes a main support 1 and a frame 2. The main support 1 is located inside the frame 2, and the main support 1 and the frame 2 are connected by ten mounting supports 3. Among them, the frame 2 is a pentagon, and all corners are designed with rounded corners. The mounting supports 3 are bent structures from the main support 1 to the frame 2, and the bending part is located between the main support 1 and the frame 2. For the convenience of description, each side of the pentagonal frame 2 is defined respectively. The five sides of the frame 2 are respectively denoted as the first side 4, the second side 5, the third side 6, the fourth side 7 and the fifth side 8. Among them, the first side 4 and the second side 5 are adjacent and have equal side lengths. The third side 6 and the fourth side 7 are opposite and have equal side lengths. The first side 4 is adjacent to the third side 6, the second side 5 is adjacent to the fourth side 7, and the side length of the fifth side 8 is greater than other side lengths and its two ends are respectively connected to the third side 6 and the fourth side 7. Then the distribution of the connection points of the ten mounting supports 3 and the frame 2 is as follows: there are two connection points on both the first side 4 and the second side 5. One connection point is close to the connection of the first side 4 and the second side 5, and the other connection point is respectively located at the centers of the first side 4 and the second side 5. There is one connection point on both the third side 6 and the fourth side 7, and they are respectively close to the connection of the first side 4 and the third side 6 and the connection of the second side 5 and the fourth side 7. There are four connection points on the fifth side 8, and the four connection points are symmetrically arranged about the center of the fifth side 8. As Figure 2, at each installation support 3 near the frame 2, a structure design of circular to square conversion is adopted. The part of the installation support 3 connected to the frame 2 is a square end. There are bolt holes designed on three faces of the square end. The square end is connected to the frame 2 through an adapter 9. The connection of the three faces has strong rigidity. In addition, two open faces are designed at the square end to facilitate the operation of docking bolts. The purpose of chamfering a large fillet at the circular to square conversion is to locally increase the strength and avoid stress concentration.

[0039] As Figure 3 , a fuel tank flange 10 and two oxidizer tank flanges 11 are provided on the frame, which are used to connect the fuel tank and the two oxidizer tanks through bolts. Among them, 12 bolt holes can be designed on the oxidizer tank flange 11 for connecting the oxidizer tank. Due to structural limitations, 9 of the bolt holes can be designed as through holes, and 3 bolt holes can be designed as blind holes, and internal threads are machined in the blind holes.

[0040] As Figure 4 As shown, three types of flow channels are provided in the main support 1, namely a fuel flow channel 13, an oxidizer flow channel, and a gas flow channel 15. Among them, the fuel tank flange 10 is the fuel inlet, and the three engine fuel inlets are respectively connected to three fuel outlets 16 on the main support 1 to supply fuel to three engines. The fuel tank flange 10 is located at the uppermost end of the main support 1. Two fuel outlets 16 are located on one side of the fuel tank flange 10, and the other fuel outlet 16 is located on the other side of the fuel tank flange 10. The fuel outlets 16 on one side of the fuel tank flange 10 and the fuel outlet 16 on the other side are symmetrically arranged with respect to the fuel tank flange 10. The fuel tank flange 10 is connected to the three fuel outlets 16 through three independent fuel flow channels 13. The oxidizer tank flange 11 is the oxidizer inlet, and the three engine oxidizer inlets are respectively connected to three oxidizer outlets 17 on the main support 1 to supply oxidizer to three engines. The three oxidizer outlets 17 and the two oxidizer tank flanges 11 are all located at the lowermost part of the main support 1 and are on the same horizontal line. The two oxidizer tank flanges 11 are located outside the two ends of the three oxidizer outlets 17. The oxidizer flow channel includes two first oxidizer flow channels 14 and a second oxidizer flow channel 18. The first oxidizer flow channel 14 is in the shape of an arc with a central angle of 135°. The oxidizers at the two oxidizer tank flanges 11 respectively enter the second oxidizer flow channel 18 through one first oxidizer flow channel 14. The second oxidizer flow channel 18 is the common oxidizer flow channel for the three oxidizer outlets 17, and reaches the three oxidizer outlets 17 respectively through the second oxidizer flow channel 18. Among them, the fuel flow channel 13, the first oxidizer flow channel 14, and the second oxidizer flow channel 18 can all be designed as pipelines with a square cross-section.

[0041] The parameters of both the fuel flow channel 13 and the oxidizer flow channel can be optimized. The equivalent inner diameter of the main pipe at the outlet of the fuel tank is 20 mm (20 mm in length and 16 mm in width), with a wall thickness of 3 mm. The equivalent inner diameter of the conduit at the outlet of the oxidizer tank is 40 mm, with a wall thickness of 3 mm. The equivalent inner diameter of the oxidizer flow channel is 32 mm, with a wall thickness of 3 mm. According to the engine thrust and specific impulse, the oxidizer flow rate under the rated condition of a single engine is calculated to be 4.15 kg / s, and the fuel flow rate is 2.5 kg / s. Based on the pipeline layout characteristics of the integrated frame in the present invention, the flow resistance of the pipeline in this integrated structure is calculated as shown in Table 1.

[0042] Table 1 Flow Channel and Medium Parameter Table

[0043]

[0044] In other embodiments of the present invention, adjustments can also be made according to the actual situation of the engine.

[0045] The cross-sections of both the oxidizer flow channel and the fuel flow channel 13 are rectangular designs. When manufacturing the frame of the present invention by 3D printing, the problem that it is difficult to ensure the forming of the top arc of the large-diameter circular conduit during horizontal printing is avoided. The large-diameter rectangular cross-section conduit can be realized by means of inclined 3D printing. An equal-area cross-section transition design is adopted from the outlets of the fuel tank and the oxidizer tank to the cross-sections of the oxidizer flow channel and the fuel flow channel 13, which not only considers the isokinetic flow of the propellant but also takes into account the product realization.

[0046] Such as Figure 6 , two attitude control mounting plates 12 are installed on the back of the main support 1. One attitude control mounting plate 12 is close to the fuel tank and is connected to the attitude control system by 2 M5 bolt through-holes and 2 M5 blind holes. The fuel tank flange 10 and the two oxidizer tank flanges 11 are led to the middle of this attitude control mounting plate 12 through the internal flow channels, and a purge gas interface can also be designed in the middle. The other attitude control mounting plate 12 is connected to the attitude control system by 4 M5 bolt through-holes. Similarly, the fuel tank flange 10 and the two oxidizer tank flanges 11 are led to the middle of the mounting plate through the internal flow channels, and a purge gas interface can also be designed in the middle.

[0047] Such as Figure 7 , three thrust chamber flanges 20 are provided on the back of the main support 1 for connecting three engines. An air port 19 is provided on the back of the main support 1. The air port 19 is connected to an external gas cylinder. The air port 19 is respectively connected to six pneumatic valves for controlling three fuel outlets 16 and three oxidizer outlets 17 through multiple gas flow channels 15. Bolt holes are provided on the thrust chamber flanges 20. In order to reduce weight, a step with a diameter of 50 mm and a height of 35 mm is dug at the center of the docking surface of each thrust chamber flange 20, and three reinforcing ribs are provided on the side of each thrust chamber flange 20, and the other parts on the side of the thrust chamber flange 20 are hollowed out.

[0048] In this embodiment, the structural stress environment of the frame is severe. Considering a 1.4-fold load, the maximum stress of the structure is in the order of 800 Mpa. At the same time, the structure is required to be lightweight. In addition, considering the selectability of 3D printing materials, the structural material is selected as titanium alloy (TC4). Compared with stainless steel 1Cr18Ni9Ti, the density of TC4 is 60% of that of 1Cr18Ni9Ti, but the mechanical properties of TC4 are better. The yield strength of titanium alloy TC4 is more than 4 times that of 1Cr18Ni9Ti.

[0049] The frame structure of the present invention is verified. When the three large-thrust orbit control engines of the aircraft work simultaneously, an axial (+X direction) thrust of 60 kN is generated and transmitted to the cabin shell through the integrated frame. At the same time, the instrument equipment is overloaded by 12g (-X direction). The wet weight of the fuel tank is 40 kg, the wet weight of a single oxidizer tank is 32 kg, and the weight of a single engine is 4.5 kg. The load considers a 1.4-fold safety factor. Fixed displacement constraints are applied to the bolt holes of the ten mounting brackets respectively, an overload (-X) of 6720 N (1.4 * 40 * 120 N) is applied to the mating surface of the fuel tank flange 10, an overload (-X) of 5376 N (1.4 * 32 * 198 N) is applied to the mating surfaces of the two oxidizer tank flanges 11 respectively, and at the same time, a thrust (+X) of 28000 N (1.4 * 20000 N) is applied to the mating surfaces of the three main thrust chamber flanges 20 respectively. The finite element mesh uses freely divided tetrahedral ten-node volume elements, the minimum side length of the element is 3 mm, and there are a total of 1447639 elements. Only in the overload condition, the maximum displacement is at the fuel tank flange 10, and the maximum displacement is 1.311 mm. Under the overload condition, the mass of the fuel tank is the largest, the overload force at the fuel tank flange 10 is the largest, and it is reasonable that the maximum displacement appears at the fuel tank flange.

[0050] The present invention combines the topology optimization of the integrated structure to design the flow channels of fuel and oxidizer and the flow channels of the attitude control system and the gas path. Through the calculation of the flow resistance of the flow channels and the design of the rectangular cross-section of the flow channels, the integrated structure meets the overall propellant supply function index. The dry weight of the integrated frame structure is 14.45 kg, with a weight reduction of 31%, meeting the overall requirement of not exceeding 15 kg. When working under two load conditions, the maximum deformation of the integrated frame meets the overall requirement of not exceeding 2 mm. By reasonably chamfering all the places where stress concentration is likely to occur in the structure, the integrated structure meets the yield strength requirement of titanium alloy TC4. Under the two working conditions, when the load considers a 1.4-fold safety factor, the maximum stress of the integrated frame does not exceed the yield strength of the titanium alloy.

[0051] In the field of high-performance aircraft, the present invention installs the aircraft power system together with attitude control modules, oxidizer tanks, fuel tanks, valves, etc. on the airframe. This integrated design can reduce the weight of the aircraft and its envelope, thereby improving the performance and reliability of the aircraft. Additionally, in the aerospace field, the design requirements of high Mach number and highly maneuverable aircraft pose higher demands on design and manufacturing processes. Their components are characterized by large sizes and many complex and irregular structures. 3D printing technology has great advantages in the integrated manufacturing of large-sized parts, the manufacturing of complex and irregular structural parts, and the manufacturing of variable-batch customized structural parts.

[0052] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An integrated frame for parallel sharing of multiple engines, characterized in that: It includes a main support (1) and a frame (2). The main support (1) is located inside the frame (2), and the main support (1) is connected to the frame (2) through a plurality of mounting supports (3). On the front of the main support (1), there is a fuel tank flange (10) and two oxidizer tank flanges (11), which are respectively used to connect the fuel tank and the oxidizer tank. On the front of the main support (1), there are three fuel outlets (16) and three oxidizer outlets (17), which are respectively used to connect the fuel inlets of three engines and the oxidizer inlets of three engines. The fuel tank flange (10) and the three fuel outlets (16) are respectively connected through three independent fuel channels (13). The two oxidizer tank flanges (11) and the three oxidizer outlets (17) are respectively connected through oxidizer channels. The fuel channels (13) and the oxidizer channels are both located inside the main support (1). The back of the main support (1) is used to connect three engines. There is an air port (19) on the back of the main support (1). The air port (19) is connected to an external gas cylinder. The air port (19) is respectively connected to six pneumatic valves for controlling the three fuel outlets (16) and the three oxidizer outlets (17) through a plurality of gas channels (15). There are two attitude control mounting plates (12) on the back of the main support (1), which are used to connect two attitude control systems.

2. The integrated frame for parallel sharing of multiple engines according to claim 1, wherein: The frame (2) is pentagonal, and each corner is a rounded structure.

3. The integrated frame for parallel sharing of multiple engines according to claim 2, characterized in that: The five sides of the frame (2) are respectively denoted as the first side (4), the second side (5), the third side (6), the fourth side (7) and the fifth side (8). Among them, the first side (4) and the second side (5) are adjacent and have equal side lengths. The third side (6) and the fourth side (7) are opposite and have equal side lengths. The first side (4) is adjacent to the third side (6), the second side (5) is adjacent to the fourth side (7), and the side length of the fifth side (8) is greater than the other side lengths and its two ends are respectively connected to the third side (6) and the fourth side (7). There are ten mounting supports (3). The connection points of the ten mounting supports (3) and the frame (2) are distributed as follows: there are two connection points on both the first side (4) and the second side (5), one connection point on both the third side (6) and the fourth side (7), and four connection points on the fifth side (8). The mounting support (3) is a bent structure from the main support (1) to the frame (2).

4. The integrated frame for parallel sharing of multiple engines according to claim 3, characterized in that: One end of the mounting support (3) close to the frame (2) is a round-to-square structure, and the round-to-square part is a rounded corner structure.

5. An integrated frame for parallel sharing of multiple engines according to any one of claims 1 to 4, characterized in that: The oxidizer channel includes two first oxidizer channels (14) and a second oxidizer channel (18). The two oxidizer tank flanges (11) are respectively connected to the second oxidizer channel (18) through two first oxidizer channels (14). The first oxidizer channel (14) is in the shape of an arc with a central angle of 135°. The second oxidizer channel (18) is respectively connected to the three oxidizer outlets (17).

6. The integrated frame for parallel sharing of multiple engines according to claim 5, characterized in that: The fuel tank flange (10) is located at the uppermost end of the main support (1). The three oxidizer outlets (17) and the two oxidizer tank flanges (11) are both located at the lowermost part of the main support (1) and are on the same horizontal line. The two oxidizer tank flanges (11) are respectively located on the outer sides of both ends of the three oxidizer outlets (17).

7. The integrated frame for parallel sharing of multiple engines according to claim 6, characterized in that: Three thrust chamber flanges (20) are provided on the back surface of the main support (1) for connecting three engines; A plurality of reinforcing ribs are circumferentially arranged on the side surface of the thrust chamber flange (20), and the structure between adjacent reinforcing ribs is a hollow structure.

8. The integrated frame for parallel sharing of multiple engines according to claim 7, characterized in that: The three thrust chamber flanges (20) are located in the middle of the main support (1) and are on the same straight line; One attitude control mounting plate (12) is located between the middle thrust chamber flange (20) and the fuel tank flange (10), and the other attitude control mounting plate (12) is located between the middle thrust chamber flange (20) and the second oxidizer flow channel (18).

9. The integrated frame for parallel sharing of multiple engines according to claim 8, characterized in that: The materials of the main support (1), the frame (2) and the mounting support (3) are all titanium alloy.

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