Light polyethylene cable net film captive balloon system

Abstract

The invention discloses a light polyethylene cable net film captive balloon system which comprises a cable film overpressure balloon suspended by a captive cable. A main air bag of the cable membrane overpressure balloon is made of a polyethylene film material, a polyethylene film is tied into a bulge shape by using warp and circumferential reinforcing ribs made of PBO fiber material ropes, and the reinforcing ribs are bound at cross nodes. Warp and circumferential rope cages are bound outside the main air bag structure, and the rope cages are connected with hanging ropes. Aiming at the configuration of the polyethylene film tethered balloon, the invention provides a design scheme of a cable net film capable of resisting higher internal and external pressure difference, the suspension problem that a pod and a tethered cable are not suitable for being directly connected with a balloon body due to a light film is solved, and the empennage structure of the polyethylene film tethered balloon is designed to provide flight stability; the weight of the captive balloon body is greatly reduced, so that the load weight is increased or the flight height is increased.

Description

Technical Field

[0001] The present invention relates to the field of tethered balloon design in an aerostat system, including the design of a tethered balloon envelope and an inflatable tail wing, and also describes a load suspension mode and a tethering method. Background Art

[0002] A tethered balloon is a lighter-than-air, unpowered balloon aircraft with an air bag filled with lighter-than-air gas, which generates upward buoyancy. A system with a tethered balloon as the core is called a tethered balloon system. The tethered balloon system includes a tethered balloon sphere, tethered cable assembly, mooring facilities, and ground-based integrated support facilities. The tethered balloon relies on buoyancy to suspend in the air. The sphere is connected to the ground mooring facilities through a tether. The height of the sphere is adjusted by adjusting the length of the tether, thereby providing a quasi-static aerial platform for other equipment.

[0003] The sphere of the tethered balloon mainly includes a polyethylene film sphere and various flexible connectors. The main airbag is filled with helium and other lighter-than-air gases to provide the required buoyancy for the launch system and is the buoyancy source for the balloon to float and fly. The auxiliary airbag of the sphere is located on the lower surface of the bottom of the sphere. The air is supplemented or discharged through the valve installed at the bottom of the sphere to adjust the internal pressure of the sphere. The tail wing on the pod is an important component for adjusting the flow field around the sphere to improve the stability of the sphere. The mooring cable is an important component of the tethered balloon. The upper side of the cable is connected to the sphere through a gathering point, and the lower side is connected to the ground anchoring facilities. It is used for the mooring, anchoring and lifting operations of the balloon, so that the sphere can achieve a fixed height and long-term residence. The rigid structure of the sphere mainly includes the nose cone, load hanger and other metal structural parts. The nose cone is located at the head of the sphere and is a rigid structural part that connects the sphere to the anchoring facilities when the balloon is anchored.

[0004] The spherical load bracket is located in the middle and lower part of the sphere and is the main load-bearing structure of the balloon load. Therefore, it is required to be lightweight and strong while being able to be in close contact with the sphere to increase the sway stability of the sphere. The mooring facility is the main equipment to ensure the anchoring and suspension of the balloon. It also provides power and control means for the collection and release of the balloon and the guidance of the mooring cable. It is also the main link in the power signal transmission channel between the ground and the sphere.

[0005] In order to maintain a certain rigidity, the tethered balloon needs to withstand a large internal and external pressure difference, which causes a large stress in the circumference of the main balloon. At present, tethered balloons mostly use polyarylate fiber composite materials with a thickness of about 200μm and a surface density of nearly 350g / m2 to withstand film stress. This makes the tethered balloon itself heavier, and also limits the flight height under the same volume and the same load weight. If a low-density polyethylene film material is used, with a thickness of 38μm and a surface density of only 36g / m2, the weight of the balloon can be reduced by nearly 9 times. The reduced mass can be converted into an increase in the hanging load and an increase in the flight altitude. Alternatively, the geometric dimensions of the tethered balloon can be reduced by 3 times and the volume by 27 times while carrying the same load and the same altitude. The reduction in the size of the balloon will greatly reduce the processing cycle and production costs, and also facilitate the field pressure maintenance and release work.

[0006] However, if a lightweight polyethylene film material is used as the main material of the tethered balloon bladder, the polyethylene film needs to be able to withstand an internal and external pressure difference of more than 500Pa. If the polyethylene film spiral body design is directly adopted, the in-plane stress will greatly exceed the film strength and cause the film to be damaged. In addition, the main bladder made of polyethylene cannot be directly used as a towing point for loads or tethered cables, and the tail cannot withstand the pressure difference by using only a partition like the tail of a traditional tethered balloon. These technical difficulties have limited the design and use of tethered balloons made of polyethylene film materials to small balloons in the past, and cannot be expanded to large-sized tethered balloons, let alone comparable to the load capacity and flight altitude of the current mainstream fabric-skinned tethered balloons. Summary of the invention

[0007] The present application proposes a lightweight polyethylene cable net film tethered balloon system. Aiming at the configuration of the polyethylene film tethered balloon, a cable net film design scheme capable of withstanding a relatively high internal and external pressure difference is proposed to solve the suspension problem caused by the lightweight film that the pod and the tethered cable are not suitable to be directly connected to the balloon body. The tail wing structure of the polyethylene film tethered balloon is designed to provide flight stability, thereby achieving a significant reduction in the weight of the tethered balloon body to increase the load weight or raise the flight altitude.

[0008] The embodiment of the present application provides a lightweight polyethylene cable net film tethered balloon system, including a cable membrane super-pressure balloon suspended by a tethering cable;

[0009] The main airbag of the cable membrane super pressure balloon is made of polyethylene film material, and PBO fiber ropes are used as warp and circumferential reinforcement ribs to squeeze the polyethylene film into a bulge shape, and the reinforcement ribs are bound at the cross nodes;

[0010] Warp and circumferential rope cages are tied outside the main airbag structure, and the rope cages are connected to the suspension ropes.

[0011] In one embodiment of the present application, a partition is welded along the circumference inside the main airbag to form vertical chambers distributed along the axial direction, and each chamber is provided with an independent inflation port.

[0012] In one embodiment of the present application, auxiliary airbag partitions are welded to both ends of the main airbag, and flanges are installed at the head and tail to control the air that is filled in or exhausted.

[0013] In one embodiment of the present application, the main airbag is a teardrop-shaped rotating body structure, and the generatrix equation includes: the head is a semi-ellipse with the major axis along the length direction of the main airbag; the middle part is a parabola, the vertex is located at the end of the minor axis of the ellipse, and is tangent to the vertex of the minor axis of the ellipse and converges at the vertex of the parabola; the tail generatrix is ​​an arc.

[0014] In one embodiment of the present application, the tail wing includes: a spherical membrane made of polyethylene film; reinforcing ribs for restraining the spherical membrane; and longitudinally extending partitions welded in the spherical membrane cavity, where the longitudinal direction of the tail wing refers to the direction from the root of the tail wing to the end of the tail wing; multiple partitions are arranged horizontally in the spherical membrane cavity to form a wing surface shape.

[0015] In one embodiment of the present application, the structure of the tail wing is a longitudinal stack of columns that are bounded by multiple circles of circumferential reinforcing ribs, and the longitudinal reinforcing ribs are connected at multiple designated points between longitudinally adjacent columns.

[0016] In one embodiment of the present application, a set of warp and circumferential reinforcements are provided on the basis of the existing warp and circumferential reinforcements as external reinforcements; the bottom pod is connected to the external reinforcements through hanging ropes and / or rope cages.

[0017] In one embodiment of the present application, the pod is connected to the nodes of the rope cage in the circumferential direction using multiple suspension ropes and is suspended below the belly of the balloon; the mooring cable is connected to the pod bracket.

[0018] In one embodiment of the present application, the pod is in the shape of an elongated strip parallel to the axis of the balloon, so that the middle portion of the balloon is in a straightened state.

[0019] In one embodiment of the present application, the rope cage is bound to the reinforcing rib cross nodes at several node positions.

[0020] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects:

[0021] The use of lightweight polyethylene film as the membrane material of the tethered balloon greatly reduces the weight of the balloon. Since the balloon has a partition inside, it can be launched without forming. At the same time, it has the advantages of long continuous hovering time, high flight altitude, wide detection range, strong survivability, good maneuverability and high cost-effectiveness. It can be widely used in military and civilian fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 A schematic diagram of the cable net membrane tethered balloon system of the present application;

[0024] Figure 2 Designing embodiments for the three-dimensional shape of the mooring system;

[0025] Figure 3 The force curves of the tethered balloon membrane in the longitudinal and circumferential directions;

[0026] Figure 4 The force distribution of the longitudinal and circumferential reinforcement ribs of the tethered balloon membrane;

[0027] Figure 5 It is the plane film cutting pattern of the main airbag of the tethered balloon;

[0028] Figure 6 This is a schematic diagram of the design of the polyethylene tethered balloon tail fin;

[0029] Figure 7 It is the tail shape of a polyethylene tethered balloon;

[0030] Figure 8 A schematic diagram of dividing the interior of the main airbag into compartments and attaching a set of reinforcing ribs to the outside of the balloon;

[0031] Fig. 9 Schematic diagram of the shape change of the main airbag after the two side points are tied during application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0033] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0034] Figure 1The schematic diagram of the cable-net film tethered balloon system of the present application is shown in FIG. The patented tethered balloon system is based on the cable-membrane super-pressure balloon and includes a sphere, mooring facilities, tethered cables, payload, ground control, etc. The present invention provides a set of non-traditional polyethylene film tethered balloon design solutions, mainly including the polyethylene film main airbag structure design, the polyethylene film tail wing structure design, and the pod and tethered cable suspension method design.

[0035] With respect to the polyethylene main airbag 11 structure, this patent proposes using PBO fiber material ropes to stretch the polyethylene film into a bulging shape in two orthogonal directions, the warp and circumferential directions, so as to reduce the local curvature radius of the film to withstand the pressure difference between the inside and outside of the main airbag.

[0036] Regarding the meridian and circumferential directions mentioned on the main airbag. The main airbag is specifically an axially symmetrical structure, with the axial direction horizontal, the left and right ends as poles, and the meridian lines intersecting at the poles. The circumferential line is a closed curve where a surface perpendicular to the axial direction intersects with the surface of the main airbag.

[0037] The edges of the main airbag are welded together to form a sealing structure, and sleeves are welded at the weld position for the reinforcement ribs to penetrate and position. The longitudinal and circumferential reinforcement ribs are bound at the intersection nodes to limit the position of the reinforcement ribs and the length of each section.

[0038] The main airbag partition is welded inside the main airbag along the circumferential direction, and a bottom vent hole is reserved. The top of each chamber is provided with an inflation port for helium to be filled.

[0039] The auxiliary airbag partitions are welded at the front and rear ends of the main airbag, such as the head auxiliary airbag 12 and the tail auxiliary airbag 13. Hard flange structures are installed at the head and tail, such as the head flange 14 and the tail flange 15, for controlling the filling and exhausting of air to control the pressure difference inside the balloon. The flange includes an air port and a helium port.

[0040] The polyethylene film tail 16 is in an inverted Y layout to enhance rolling stability. The polyethylene film tail is fixedly connected to the outer rope cage through ropes. At the same time, each bubble of the polyethylene film tail is fixedly connected through a common point.

[0041] For the tail structure of polyethylene tethered balloons, this patent also proposes stacking bubbles restrained by circumferential reinforcement ribs, and connecting longitudinal reinforcement ribs at designated points between adjacent bubbles to reduce the stress on the tail film. At the same time, a partition is used inside the bubble to form the shape of the wing surface.

[0042] In view of the suspension method of polyethylene tethered balloons, this patent proposes to bundle a set of longitudinal and circumferential rope cages on the outside of the main airbag of the cable membrane structure. The outer rope cage is not connected to the balloon membrane, but is bound to the cross nodes of the reinforcing ribs at certain node positions. The pod 17 below the tethered balloon can adopt a "king" structure, for example, on which the flight control, energy, measurement and control, and security control components required for the balloon flight are arranged. Structurally, a suspension rope 18 is used to connect the outer rope cage and suspend it under the belly of the tethered balloon.

[0043] For example, in the example of a group of rope cages being put outside the main airbag, the binding position of the outer rope cage and the cross node of the reinforcing ribs on the main airbag is the node of the meridian reinforcing ribs on the top of the balloon.

[0044] For another example, when the pod is suspended under the belly of the main airbag by ropes, multiple ropes are used to connect to the nodes of the outer rope cage in the circumferential direction to limit lateral rolling. At the same time, multiple ropes are used to connect the front and rear bottom nodes of the main airbag and the pod frame to limit the front and rear swing of the hanger.

[0045] The mooring cable 19 is connected to the hanger and supplies power to the onboard system through the cable. The bottom of the mooring cable is connected to the winch on the ground anchoring vehicle 20 to achieve the ascent and descent of the moored balloon system. For example, the mooring cable connecting the balloon to the ground anchoring vehicle is connected to a "W"-shaped pod bracket.

[0046] Figure 2 This is an example of a three-dimensional design of a tethered system. This example assumes that the volume of the polyethylene tethered balloon is 540m 3 The main airbag is a teardrop-shaped rotating body structure, and its surface presents longitudinal reinforcing ribs 21, circumferential reinforcing ribs 22 and a bulge 23.

[0047] The contour line of the main airbag's axial maximum cross-section is smoothed to be the mother line, ignoring the bulge. The teardrop-shaped mother line equation is generally composed of three segments. The head 24 is a semi-ellipse, whose semi-major axis is along the length direction of the tethered balloon and the short semi-axis is arranged along the height direction of the balloon. The middle part 25 mother line is a parabola, the vertex is located at the end of the short semi-axis of the ellipse, and it is tangent to the ellipse and converges at the vertex of the parabola. The tail 26 mother line is a circular arc, tangent to the end of the parabola.

[0048] The generatrix equations of the teardrop-shaped body of revolution are:

[0049]

[0050] y(X)a1+c(parabola segment)

[0051]

[0052] Among them, x and y are the axial coordinate and radius respectively, a, b, a1, c, x r, and r are all shape parameters. For example, the specific values ​​are a=-7.494; b=6.915; a1=-0.0054; c=6.9150; x r =33.5310; r = 0.75. As an example, it is calculated that the main airbag is 22.18m long and has a maximum diameter of 7.34m. The tail wing adopts an inverted Y-shaped layout.

[0053] As an example, the polyethylene tethered balloon has 16 bulges along the warp direction, that is, 15 circumferential reinforcing ribs. There are 24 warp reinforcing ribs. The warp lengths of each bulge are [4.14, 1.57, 1.16, 1.08, 1.08, 1.16, 1.16, 1.24, 1.24, 1.32, 1.49, 1.32, 1.57, 1.74, 2.48] m. The fully inflated polyethylene tethered balloon is shown in Figure 1. Figure 2 The spherical membrane is subjected to the longitudinal and circumferential forces as shown in Figure 3 As shown in Figure 2, it can be concluded that the bulges at both ends of the balloon can be appropriately extended in the longitudinal direction due to the small force. At the same time, the membrane stress of the balloon reaches the maximum value at the maximum diameter in the middle, which is close to 3.5MPa. The circumferential and longitudinal reinforcement tensions are shown in Figure 2. Figure 4 As shown in the figure, the maximum circumferential tension is close to 85kg. The reinforcement ribs still use 3mm diameter PBO fiber ropes, and a single rope can withstand a tension of 800kg, which can meet the needs of circumferential reinforcement ribs. The plane film cutting shape of each bulge after unfolding is fitted to obtain the plane film cutting pattern of the main airbag of the tethered balloon as shown in the figure. Figure 5 As shown. The surface area of ​​a single membrane reaches 26.94m 2 , the mass is only 0.97kg.

[0054] The outer contour in the figure is the final plane cut film shape of the tethered balloon; the edge shape 52 of the balloon film required by the simulation calculation is similar to a wave shape and is not suitable for processing and manufacturing. Therefore, the first busbar 51 is fitted on the basis of the wave shape to facilitate processing. The second busbar 53 is the meridian reinforcement busbar after the surface of the tethered balloon is bulged under the action of the circumferential reinforcement ribs 55; the shape of the third busbar 54 is the shape of the balloon busbar if the bulge configuration is not adopted, but a smooth simple rotating body structure. It can be concluded that after the balloon is bulged due to the reinforcement ribs, the balloon needs more balloon film material, that is, the first busbar 51 has a lot more balloon film material than the third busbar 54.

[0055] The design of polyethylene tethered balloon tail is shown below: Figure 6 The basic design concept of the tail wing is to stack columns bounded by circles of circumferential reinforcing ribs 61, and at the same time, the upper and lower adjacent columns (such as Figure 6The top large bubble, the middle large bubble, and the bottom large bubble are connected with longitudinal reinforcing ribs 63 at designated points 62. That is to say, the conventional tail wing is constrained by the interlayer line, while the polyethylene cable membrane tail wing is constrained by the point of the reinforcing ribs.

[0056] The tail wing is provided with a plurality of longitudinal reinforcing ribs, and the longitudinal reinforcing ribs are also used to consolidate with the main airbag reinforcing ribs at the root of the tail wing. The longitudinal direction of the tail wing refers to the direction from the root of the tail wing to the end of the tail wing. Therefore, it can be understood that the circumferential direction of the tail wing refers to the direction substantially perpendicular to the longitudinal direction. Preferably, the circumferential section of the tail wing is parallel to the axial direction of the main airbag.

[0057] The bottom of the tail wing leaves space for the main airbag bulge to expand, so that the bottom of the tail wing conforms to the main airbag bulge in the longitudinal direction. For example, for the polyethylene tethered balloon tail wing, a wider NACA0024 symmetrical airfoil is selected. Install it on the second and third bulges from the end of the main airbag. The installation method is that the tail wing reinforcement ribs and the main airbag reinforcement ribs are consolidated at the bottom. At the same time, space is left at the bottom of the tail wing after the second and third bulges of the main airbag are fully expanded.

[0058] In addition, in order to maintain the flat shape of the tail wing, the longitudinal force is smaller than the lateral force, and a partition 64 is further installed in the longitudinal direction of the tail wing to form the flat shape of the tail wing. The shape of the partition is a rectangle, an isosceles trapezoid or an isosceles triangle.

[0059] The deformed tail wing after being subjected to a pressure difference of 300Pa is shown in Figure 7 The maximum stress on the longitudinal partition is only 0.01MPa, and the maximum stress on the tail wing membrane is 2.5MPa. Figure 7 is the shape of the tail after deformation. The initial shape is Figure 6 After the tail wing is deformed, the film is bulged under the action of the reinforcement ribs, and the overall shape of the tail wing is no longer regular.

[0060] In order to achieve non-shaped release, the polyethylene tethered balloon can adopt the following two designs at the same time, as shown in the schematic diagram Figure 8 shown.

[0061] Design 1, the polyethylene tethered balloon has a set of warp and circumferential reinforcement ribs 81 on the basis of the existing warp and circumferential reinforcement ribs, and the two sets of reinforcement ribs are fixed at several intersections 82. The fixed points are the nodes at the warp reinforcement ribs at the top of the balloon in the figure, represented by protruding dots. R1-R8 and L1-L8 represent the circular chambers counted from the middle of the balloon to the right and left respectively. The bottom pod is not directly connected to the balloon film and the reinforcement ribs bound to the sleeve to avoid tearing the polyethylene balloon film. Or,

[0062] Design 2, the interior of the main airbag of the polyethylene tethered balloon is divided into a circumferential cross-section partition 83 in the circumferential direction to restrict the free flow of helium and prevent the balloon from becoming unstable from a horizontal lying posture.

[0063] The auxiliary airbags at both ends are provided with inflation holes 84, 85 respectively.

[0064] In one embodiment, a bottom auxiliary airbag 86 is arranged along the length direction at the lower part of the main airbag, and the internal chambers are connected. A long strip pod 87 is arranged below the bottom auxiliary airbag.

[0065] The geometry and force of the polyethylene tethered balloon were simulated when it was released in a non-shaped manner. The results are as follows: Fig. 9 As shown in the figure, (a) state 1, non-formed release on the ground, helium is filled at the top of the balloon; (b) state 2, the balloon gradually expands during the launch; (c) state 3, the balloon gradually expands during the launch, and the balloon membranes at both ends gradually unfold; (d) state 4, nearly fully expanded. The balloon gradually expands during the launch. Because the tethered balloon is designed with a circumferential partition inside to limit the flow of helium, and a long strip pod parallel to the balloon axis is used, the middle part is always in a straightened state.

[0066] The operation method of polyethylene tethered balloon is as follows:

[0067] Connect the mooring cable to the hanger. Then lay the polyethylene film tethered balloon flat on the ground along the meridian, connect the hanger to the polyethylene outer rope cage, and connect the three tail wings. Fill each chamber of the main airbag with helium. The proportion of helium filling must be strictly controlled to ensure that the height of each chamber of the main airbag is consistent and can be kept level with the bottom pod. During the helium filling process, the left and right sides of the main airbag are towed by a winch trolley to prevent the impact of gusts during release. After the main airbag is inflated, cut the traction rope between the winch trolley and the main airbag, and the tethered balloon will be launched.

[0068] During the ascent, the balloons gradually collide and the tail gradually expands and takes shape. After reaching the ceiling altitude, air is pumped into the tail to shape it. After the balloon's attitude stabilizes, the payload can begin to work.

[0069] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0070] It will be understood by those skilled in the art that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, parts and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, parts, components and / or combinations thereof. It should be understood that when a component is "connected" to another component, it may be directly connected to the other component, or there may be intermediate components. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0071] Those skilled in the art will understand that unless otherwise defined, all terms (including technical, technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.

[0072] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A lightweight polyethylene cable net film tethered balloon system, characterized in that: It includes a cable-membrane super-pressure balloon suspended by a mooring cable; The main airbag of the cable membrane super pressure balloon is made of polyethylene film material, and PBO fiber ropes are used as warp and circumferential reinforcement ribs to squeeze the polyethylene film into a bulge shape, and the reinforcement ribs are bound at the cross nodes; Warp and circumferential rope cages are tied outside the main airbag structure, and the rope cages are connected to the suspension ropes.

2. A lightweight polyethylene cable net film tethered balloon system as claimed in claim 1, characterized in that: The main airbag has a partition layer welded along the circumference inside to form vertical chambers distributed along the axial direction, and each chamber is provided with an independent inflation port.

3. A lightweight polyethylene cable net film tethered balloon system as claimed in claim 1, characterized in that: Auxiliary airbag partitions are welded at both ends of the main airbag, and flanges are installed at the head and tail to control the air filled in or exhausted.

4. A lightweight polyethylene cable net film tethered balloon system as claimed in claim 1, characterized in that: The main airbag is a teardrop-shaped rotating body structure, and the generatrix equation includes: the head is a semi-ellipse with the major axis along the length direction of the main airbag; the middle part is a parabola, the vertex is located at the end of the minor axis of the ellipse, and is tangent to the vertex of the minor axis of the ellipse and converges at the vertex of the parabola; the tail generatrix is ​​an arc.

5. A lightweight polyethylene cable net film tethered balloon system as claimed in claim 1, characterized in that: The rear wing includes: Ball membrane made of polyethylene film; A reinforcing rib, used to hold the spherical membrane; And a longitudinally extending partition welded in the spherical membrane cavity, wherein the longitudinal direction refers to the direction from the tail root to the tail end; a plurality of partitions are arranged transversely in the spherical membrane cavity.

6. The polyethylene film airship inflatable tail wing according to claim 1, characterized in that: The structure of the tail wing is a longitudinal stack of columns that are bounded by multiple circles of circumferential reinforcing ribs, and the longitudinal reinforcing ribs are connected at multiple designated points between adjacent longitudinal columns.

7. A lightweight polyethylene cable net film tethered balloon system as claimed in claim 1, characterized in that: On the basis of the existing warp and circumferential reinforcement ribs, another set of warp and circumferential reinforcement ribs are provided as external reinforcement ribs; The bottom pod is connected to the external stiffeners by suspension ropes and / or rope cages.

8. A lightweight polyethylene cable net film tethered balloon system as claimed in claim 1, characterized in that: The gondola is connected to the nodes of the rope cage in the circumferential direction by using multiple strands of suspension ropes and is suspended below the belly of the balloon; the mooring cable is connected to the gondola bracket.

9. A lightweight polyethylene cable net film tethered balloon system as claimed in claim 1, characterized in that: The gondola is in the shape of a long strip parallel to the axis of the balloon, so that the middle part of the balloon is in a straightened state.

10. The lightweight polyethylene cable net film tethered balloon system according to claim 1, characterized in that: The rope cage is bound to the reinforcing rib intersection nodes at several node positions.

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