RU2283798C2 - Load-bearing panel of spacecraft solar battery (versions) - Google Patents

Abstract

FIELD: rocketry and space engineering; structural members of spacecraft solar batteries.

SUBSTANCE: proposed load-bearing panel of solar battery has frame and load-bearing upper and lower bases. Mounted tightly in between said bases and frame is cellular filler; load-bearing partitions are mounted perpendicularly relative to bases. Each version of invention provides drain holes in side surfaces of each honeycomb cell of filler and in load-bearing partitions for communication of interior of honeycomb cells. According to first version of invention, drain holes for communication of interiors of honeycomb cells with external medium are made in at least one member of frame; according to second version of invention, drain holes are made in lower base of panel smoothly over area of its surface; according to third version of invention, drain holes are made in at least one member of frame and in lower base of panel smoothly over area of its surface. Total areas of drain holes in said structural members of load-bearing panel are determined taking into account total volume of gas medium in honeycomb cells, drainage coefficients of drain holes ands maximum pressure differential in launch vehicle flight trajectory acting on panel bases.

EFFECT: enhanced structural strength with no increase of mass; facilitated procedure of manufacture; enhanced operational reliability.

4 cl, 4 dwg

Description

The invention relates to the field of aerogasdynamics of aircraft (LA) and can be used in rocket science in the design and creation of panels of the solar battery (SB) of spacecraft (SC), made by a three-layer carrier scheme.

Known and widely used in aviation in the manufacture of aircraft elements (fuselage, plumage, wing, etc.), panels made according to a three-layer load-bearing scheme, containing a frame (frame), bearing upper and lower bases, between which there is a filler in the form of honeycombs [ one].

Designed for the perception and transmission of distributed loads acting on the elements of the aircraft, the panels made according to a three-layer scheme with honeycomb core provide greater rigidity and high bearing capacity. When loading the panel, shear and lightweight honeycomb perceives lateral shear and protects thin bearing layers from loss of stability during longitudinal compression.

The disadvantages of this technical solution include the increased weight of the frame elements and the bearing bases of the panels due to significant pressure drops acting on the panel elements along the flight path of the aircraft when the aircraft altitude changes.

The spacecraft SB panels used in rocket science are known for the installation of sensitive elements (photovoltaic converters) on the spacecraft power supply system on them. The panels are also made in a three-layer load-bearing pattern and contain a frame that carries upper and lower bases, between which a filler in the form of honeycombs is sealed, as well as power partitions sealed perpendicular to the bases to increase the stiffness of the panel [2]. To reduce the weight of the construction of the SB panels, the frame, bearing bases and partitions are made of lightweight materials.

Bearing panels SB SC used in rocket science, as well as panels used in aviation, provide greater rigidity and high load-bearing capacity of a three-layer structure of a SB panel with honeycomb core.

The disadvantages of this technical solution include the reduced structural strength of the SB load-bearing panels and the possibility of losing its general and local stability when deviating from the panel manufacturing and operation technology due to more significant aerodynamic loads acting on the elements of the spacecraft SB panels, as compared to aviation loads. In this case, the external pressure acting on the SC SC panel along the flight path of the launch vehicle (LV) varies over a wider range: from atmospheric (at Earth level when the launch of the LV) to practically zero when it is launched into interplanetary space, and the pressure inside the sealed panel along the flight path, the pH remains atmospheric.

The technical solution [2] was adopted by the authors as a prototype of the SC SC panel.

The objective of the invention is to increase the structural strength of the supporting panels of the spacecraft SB without increasing their mass when the spacecraft is launched by a launch rocket into interplanetary space.

The problem is solved in such a way (option 1) that in the support panel of the spacecraft satellites, containing the frame, the upper and lower bases, between which a filler in the form of honeycombs is sealed, power partitions sealed perpendicular to the bases, according to the invention, in the side surfaces of each filler cell and through partitions, through drainage holes are made, communicating the internal volumes of the cells with each other, and in the frame, at least in one frame element, drainage holes are made, communicating the internal volumes of the cells with the external environment, while the total effective area of the drainage holes in the combs, partitions and frame is determined from the ratios:

Where

S ₁ [cm ² ] is the total area of drainage holes in the end surface of the cells;

S ₂ [cm ² ] is the total area of drainage holes in the frame;

V [m ³ ] is the total volume of the gaseous medium in cells;

μ ₁ - flow coefficient of drainage holes in cells and partitions;

μ ₂ - flow coefficient of drainage holes in the frame;

ΔР [kgf / cm ² ] - maximum along the flight path of the LV differential pressure of the gas medium acting on the base of the panel;

a, b - coefficients depending on the parameters of the launch vehicle trajectory approximating the curve of the effective area of the drainage holes in the frame on the maximum differential pressure path acting on the base of the panels.

The problem is also solved in such a way (option 2) that, in the support panel of the SB KA, containing a frame, bearing upper and lower bases, between which a filler in the form of honeycombs is sealed, power partitions sealed perpendicular to the bases, according to the invention, in the side surfaces of each cell the filler and the partitions made drainage holes that communicate the internal volumes of the honeycomb with each other, and in the lower base of the panel evenly made over the surface of the surface drainage holes that communicate the inner the volume of cells with the external environment, while the total effective area of drainage holes in the cells, partitions and lower base is determined from the ratios:

Where

S ₁ [cm ² ] is the total area of drainage holes in the end surface of the cells;

S ₃ [cm ² ] is the total area of the drainage holes in the lower base;

V [m ³ ] is the total volume of the gaseous medium in cells;

μ ₁ - flow coefficient of drainage holes in cells and partitions;

μ ₃ - flow coefficient of drainage holes in the lower base;

ΔР [kgf / cm ² ] - maximum along the flight path of the LV differential pressure of the gas medium acting on the base of the panel;

a, b - coefficients depending on the parameters of the launch vehicle trajectory, approximating the curve of the dependence of the effective area of the drainage holes in the base of the panels on the maximum differential pressure path acting on the base of the panel.

The problem is also solved in such a way (option 3) that, in the support panel of the spacecraft SB, containing the frame, the upper and lower bases, between which a filler in the form of honeycombs is sealed, power partitions sealed perpendicular to the bases, according to the invention, in the side surfaces of each cell through the filler and the partitions, through drainage holes are made, communicating the internal volumes of the honeycombs with each other, and in the frame, in at least one frame element, and in the lower base of the panel uniformly over its area over awns performed drainage port communicating with the internal volume of the cells external environment, wherein the total effective area of the drainage holes in the cells, the partitions, and the lower base frame is determined from the relations:

Where

S ₁ [cm ² ] is the total area of drainage holes in the end surface of the cells;

S ₂ , S ₃ [cm ² ] - the total area of the drainage holes in the frame and lower base, respectively;

V [m ³ ] is the total volume of the gaseous medium in cells;

μ ₁ - flow coefficient of drainage holes in cells and partitions;

μ ₂ , μ ₃ - flow rate of drainage holes in the frame and the lower base of the panel, respectively;

ΔP [kgf / cm ² ] - maximum along the flight path of the LV differential pressure of the gas medium acting on the base of the panel;

a, b - coefficients depending on the parameters of the launch vehicle trajectory, approximating the curve of the dependence of the effective area of the drainage holes in the frame and the lower base of the panel on the maximum differential pressure path acting on the base of the panel.

The technical results of the invention are:

- reduction of pressure drops acting on the bases and sensitive elements of the SB panel with the minimum allowable pressure drops acting on the walls of the aggregate cells;

- determination of the effective area of drainage holes in the combs, frame, bearing bases and partitions of the panel;

- determination of the influence of the trajectory parameters (number M, flight altitude H) on the effective area of the drainage holes.

The invention is illustrated by the diagrams of the SC SB panel and a graph of the change in excess pressure acting on its elements.

Figure 1, 2 and 3 shows a diagram of the panel of the SC SC, made respectively in options 1, 2 and 3, and its fragments are highlighted, where:

1 - frame;

2 - upper base;

3 - lower base;

4 - placeholder;

5 - partitions;

6 - drainage holes;

7 - sensitive elements.

Here, arrows indicate the direction of flow of the gas medium in the honeycombs of the panel aggregate and its outflow into the external environment.

Figure 4 shows the dependence of the maximum along the flight path of the LV differential pressure ΔР (ΔР = Rvn-Rnar) of the gas medium acting on the base of the panels, on the relative effective area of the passage sections of the drainage holes μ · S / V, where:

Rvn - pressure of the gaseous medium inside the panel (in aggregate honeycombs);

Rnar is the pressure of the gaseous medium outside the panel.

The carrier panel SB KA (figure 1, 2, 3) contains a frame 1, bearing the upper base 2 and the lower base 3, as well as power partitions 5 mounted perpendicular to these bases. Between the bases hermetically placed filler 4 in the form of honeycombs. Sensitive elements 7 of the spacecraft power supply system are installed on the upper base 2.

In the lateral surfaces of each honeycomb honeycomb 4 and power partitions 5, in contrast to the prototype, in each embodiment, drainage holes 6 are made, communicating the internal volumes of the honeycomb with each other and with the external environment (see view A and section along BB).

In option 1 (FIG. 1), the internal volumes of the cells communicate with the external environment through drainage holes 6 made in frame 1, in at least one of its elements.

In option 2 (figure 2), the internal volumes of the cells communicate with the external environment through drainage holes 6 made in the bearing lower base 3, evenly spaced over the area of its base.

In option 3 (FIG. 3), the internal volumes of the cells communicate with the external environment through drainage holes 6 made in the frame 1, in at least one of its elements, as well as in the supporting lower base 3, evenly distributed over the area of its base.

Due to the uniform arrangement of the drainage openings over the area of the base of the panel, a uniform or close to uniform distribution of pressure in the honeycomb cells of the aggregate and, consequently, pressure differences acting on the base of the panel is ensured. This eliminates the concentration of stresses at the junction of the elements of the panel from uneven pressure drops, which simplifies the manufacturing technology of panels and increases the reliability of its operation in the presence of latent defects in its manufacture, for example, when non-gluing individual elements of the honeycomb core with bearing bases.

The choice of panel drainage option is determined by the permissible operating loads acting on the base of the panels along the LV flight path, taking into account the structural and technological features of the panel manufacturing.

The total effective area of the drainage holes in the frame 1, in the honeycomb cells of the aggregate 4, the partitions 5 and the lower base 3 for a given flight path of the LV is determined by the relations (1), (2) and (3), for options 1, 2 and 3, respectively, with taking into account the coefficients a, b included in these relations, depending on the parameters of the LV trajectory.

Formulas (1), (2) and (3) contain a mathematical description of the dependence of the relative total effective area of the drainage holes μ · S / V on the maximum pressure drop ΔР along the flight path of the LV and are obtained from the analysis of the gas medium flow in a system of gas-dynamic interconnected containers, formed by drained honeycomb aggregate 4 with power partitions 5, the upper base 2 and lower base 3 with its subsequent outflow into the external environment.

In rocket science, frame 1 is made of carbon fiber, bearing bases 2 and 3, and also power partitions 5 are made of titanium. Aggregate 4 in the form of honeycombs is made of aluminum alloy and hermetically attached to the upper base 2 and lower base 3 of the panel using, for example, VKV-9 aviation glue. Also, the sensitive elements 7 SB are attached to the upper base 2.

The carrier panel SB KA operates as follows.

Since in the lateral surfaces of each honeycomb honeycomb 4 and panel elements (FIGS. 1, 2 and 3), in contrast to the prototype, drainage holes 6 are made when the spacecraft is flying as part of the LV head unit, as well as in the spacecraft’s autonomous flight, after the fairings are reset of the head block, the gas medium flows between the aggregate honeycombs 4, the power partitions 5 and its outflow through the drainage holes in the frame 1 and the lower base 6 into the external medium (see section on explosives). The flow of the gas medium occurs with an insignificant delay in the equalization of pressure in the honeycomb aggregate 4.

In this case, the outflow of the gas medium from the cells of the aggregate 4 into the external medium occurs at a subsonic speed with no locking in the cells of the aggregate 4, since the total effective area μ ₂ · S _{2 of the} drainage holes 6 in frame 1 and μ ₃ · S ₃ is in the lower base 3 are made greater than or equal to the total effective area μ ₁ · S ₁ in the honeycombs of the aggregate 4 with power partitions 5 (μ ₂ · S ₂ ≥ μ ₁ · S ₁ , μ ₃ · S ₃ ≥ μ ₁ · S ₁ ).

During the flight of the spacecraft as part of the LV head block, the maximum pressure difference ΔР (Fig. 4), which acts on the bases of panels 2 and 3, is realized in accordance with formulas (1), (2) and (3). In this case, the gas medium from the honeycomb aggregate 4 flows into a closed volume under the head fairing, the maximum allowable pressure drop in which, compared with the external along the flight path of the launch vehicle, is determined by the well-known technical solution using the compartment drainage system [3].

In the autonomous flight of the spacecraft inside the panel of the hull, the internal pressure P _VN is set close to atmospheric (static ambient atmosphere). The pressure differences ΔP between the cells of the aggregate 4, as well as the internal pressure Rv in the cells of the filler 4 and the external environment Rnar acting on the upper base 2 and lower base 3 of the panel, are close to zero.

Thus, the pressure drops acting on the panel elements and the sensitive elements of the spacecraft power system installed on it are reduced. Thus, the structural strength of the spacecraft satellites is increased without increasing the mass of the spacecraft, which leads to the achievement of the task.

In addition, due to the reduction in pressure drops acting on the panel elements, the manufacturing and installation technology of the SB SC panel is simplified and its operation reliability is increased.

The calculations performed for the panel of the hull designed for the Yamal spacecraft [2], launched by the Proton rocket, showed that the pressure drops ΔP acting on the panel base, compared with the prototype, decrease by an order of magnitude and practically approach zero.

Currently, the technical solution has been tested experimentally and is being implemented on spacecraft developed by the enterprise.

The technical solution can be used for various types of spacecraft: near-Earth, interplanetary, automatic, manned and other spacecraft.

The technical solution can also be applied in aviation, for example, using the SB panel as part of an airplane wing element. In this case, the effective area of the drainage holes in the panel elements is determined taking into account the maximum pressure drops acting on the wing elements along the flight path of the aircraft.

Literature

1. Aviation. Encyclopedia. M .: TsAGI, 1994, p. 529.

2. At the turn of two centuries (1996-2001). Ed. Acad. Yu.P. Semenova. M .: RSC Energia named after SP Korolev, 2001, p. 834.

3. Patent RU 2145563 C1.

Claims (3)

1. The supporting panel of the solar battery of the spacecraft, containing the frame, the upper and lower bases, between which a placeholder in the form of honeycombs is sealed and power partitions perpendicular to the bases, characterized in that through drainage holes are made in the lateral surfaces of each placeholder cell and power partitions, communicating the internal volumes of the cells with each other, and in at least one element of the frame there are drainage holes communicating the internal volumes of the cells with the external environment, while the total the effective area of drainage holes in the honeycombs, power partitions and frame is determined from the relations μ ₁ · S ₁ / V = a · ΔP ^-b , μ ₂ · S ₂ / V≥μ ₁ · S ₁ / V, where S ₁ - the total area of the drainage holes in the side surfaces of the honeycomb and power partitions, cm ² ; S ₂ - the total area of drainage holes in the frame, cm ² ; V is the total volume of the gaseous medium in cells, m ³ ; μ ₁ is the flow coefficient of drainage holes in the side surfaces of the cells and power partitions; μ ₂ - flow coefficient of drainage holes in the frame; ΔР is the maximum differential pressure of the gas medium along the flight path of the launch vehicle, acting on the base of the panel, kgf / cm ² ; a, b - coefficients depending on the parameters of the launch vehicle trajectory, approximating the curve of the effective area of the drainage holes in the frame on the maximum differential pressure path acting on the base of the panel. 2. The supporting panel of the solar battery of the spacecraft, containing the frame, the upper and lower bases, between which the placeholder is sealed in the form of honeycombs and power partitions perpendicular to the bases, characterized in that drainage holes are made in the lateral surfaces of each placeholder cell and power partitions, communicating internal volumes of cells between each other, and in the lower base of the panel drainage holes are made uniformly over its surface area, communicating internal volumes of cells with an external medium , The total effective area of the drainage holes in the cells, power and partitions the lower base panel is defined by the relations μ ₁ · S ₁ / V = a · ΔP ^-b , μ ₃ · S ₃ / V≥μ ₁ · S ₁ / V, where S ₁ - the total area of the drainage holes in the side surfaces of the honeycomb and power partitions, cm ² ; S ₃ - the total area of the drainage holes in the lower base of the panel, cm ² ; V is the total volume of the gaseous medium in cells, m ³ ; μ ₁ is the flow coefficient of drainage holes in the side surfaces of the cells and power partitions; μ ₃ - flow coefficient of drainage holes in the lower base of the panel; ΔР is the maximum differential pressure of the gas medium along the flight path of the launch vehicle, acting on the base of the panel, kgf / cm ² ; a, b - coefficients depending on the parameters of the launch vehicle trajectory, approximating the curve of the effective area of the drainage holes in the lower base of the panel on the maximum differential pressure path acting on the base of the panel. 3. The supporting panel of the solar battery of the spacecraft, containing the frame, the upper and lower bases, between which the placeholder is sealed in the form of honeycombs and power partitions perpendicular to the bases, characterized in that through drainage holes are made in the lateral surfaces of each placeholder cell and power partitions, communicating the internal volumes of the honeycombs with each other, and in at least one frame element and in the lower base of the panel, drainage holes are made uniformly over the surface area thereof, with the total internal volume of the cells with the external environment, while the total effective area of the drainage holes in the cells, power partitions, frame and lower base of the panel is determined from the ratios μ ₁ · S ₁ / V = a · ΔP ^-b , μ ₂ · S ₂ / V≥μ ₁ · S ₁ / V, μ ₃ · S ₃ / V≥μ ₁ · S ₁ / V, where S ₁ - the total area of the drainage holes in the side surfaces of the honeycomb and power partitions, cm ² ; S ₂ , S ₃ - the total area of the drainage holes in the frame and the lower base of the panel, respectively, cm ² ; V is the total volume of the gaseous medium in cells, m ³ ; μ ₁ is the flow coefficient of drainage holes in the side surfaces of the cells and power partitions; μ ₂ , μ ₃ - flow rates of drainage holes in the frame and the lower base of the panel, respectively; ΔР is the maximum differential pressure of the gas medium along the flight path of the launch vehicle, acting on the base of the panel, kgf / cm ² ; a, b - coefficients depending on the parameters of the launch vehicle trajectory, approximating the curve of the dependence of the effective area of the drainage holes in the frame and the lower base of the panel on the maximum differential pressure path acting on the base of the panel.

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