Method for simulating external heat flow of light inlet of large-aperture space camera

Abstract

The invention relates to the technical field of thermal control of spacecrafts, in particular to an external heat flow simulation method for a light inlet of a large-aperture space camera. The external heat flow simulation method for the light inlet of the large-aperture space camera comprises the following steps that a simulation analysis model of a simulation space camera is established, and a simulation light shield of the simulation space camera is of a non-full size; establishing a ground test analysis model of the test space camera based on the simulation analysis model; and simulating the test external heat flow of the light inlet of the test space camera based on the ground test analysis model. The size limitation of a large-aperture space camera and a full-size light shield is broken through, and the simulation of the external heat flow of the light inlet of the large-aperture space camera is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of spacecraft thermal control, and particularly relates to a method for simulating external heat flux at the light entrance of a large-aperture space camera. Background Art

[0002] Thermal control is one of the important technologies to ensure the imaging quality of a space camera. Thermal deformation caused by changes in external heat flux during on-orbit operation is the key factor leading to changes in the imaging performance of the camera, and corresponding thermal control measures are required to ensure the temperature level and temperature gradient of the camera. Whether the external heat flux can be accurately simulated in ground tests determines the effectiveness of the ground verification of the thermal control of the space camera.

[0003] For a large-aperture space camera in a geostationary orbit, an inclined cut sunshade is generally designed at the light entrance to prevent direct sunlight from entering the internal optical system of the camera, thereby avoiding temperature disturbances to the opto-mechanical structure of the camera and high-temperature damage to components such as detectors. The length of the sunshade is related to the aperture of the camera and the sunlight avoidance strategy, and can reach more than ten meters. However, for the ground thermal test of a large-aperture space camera, due to the total length of the camera and the sunshade reaching more than ten meters, limited by the size of the space environment simulator, it is impossible to conduct tests with a full-size sunshade. In addition, the number of electric heaters used to simulate the absorption of external heat flux by the full-size sunshade and the workload brought by arranging welding wires are huge, and it is not easy to implement a longer full-size sunshade for future larger-aperture space cameras. Therefore, how to break through the size limitations of large-aperture space cameras and full-size sunshades and achieve the simulation of external heat flux at the light entrance of large-aperture space cameras has become an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present invention aims to provide a method for simulating external heat flux at the light entrance of a large-aperture space camera, which breaks through the size limitations of large-aperture space cameras and full-size sunshades and realizes the simulation of external heat flux at the light entrance of large-aperture space cameras.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows: The present invention provides a method for simulating external heat flux at the light entrance of a large-aperture space camera, including the following steps: establishing a simulation analysis model of a simulated space camera, wherein the simulated sunshade of the simulated space camera is non-full-size; establishing a ground test analysis model of a test space camera based on the simulation analysis model; and simulating the test external heat flux at the light entrance of the test space camera based on the ground test analysis model.

[0006] Further, a simulation analysis model of the simulated space camera is established, wherein the simulated sunshade of the simulated space camera is non-full-size, specifically including: establishing the simulation analysis model according to the full-size of the simulated sunshade, and calculating the simulated external heat flux of the light inlet of the simulated space camera; loading simulation heat loads on the simulation partitions according to the simulation partitions of the simulated sunshade and the corresponding simulation heat fluxes of the simulation partitions to obtain the simulated external heat flux; changing the full-size of the simulated sunshade to the non-full-size, and the length of the non-full-size is greater than the diameter of the light inlet of the simulated space camera.

[0007] Further, establishing the simulation analysis model according to the full-size of the simulated sunshade and calculating the simulated external heat flux of the light inlet of the simulated space camera specifically include: establishing the simulation analysis model with the full-size of the simulated sunshade based on the main body of the actual space camera, the space environment conditions and the actual operating orbit conditions; calculating the transient absorbed external heat flux on the outer surface of the simulated sunshade, the temperature distribution on the inner surface of the simulated sunshade, and the first external heat flux from the simulated sunshade at the light inlet based on the simulation analysis model.

[0008] Further, before loading the simulation heat loads on the simulation partitions according to the simulation partitions of the simulated sunshade and the corresponding simulation heat fluxes of the simulation partitions to obtain the simulated external heat flux, the method further includes: dividing the outer surface of the simulated sunshade according to the principle of similar heat flux density of the transient absorbed external heat flux on the outer surface of the simulated sunshade, and multiplying the heat flux density by the area of the simulation partition to obtain the corresponding simulation heat flux of the simulation partition.

[0009] Further, loading the simulation heat loads on the simulation partitions according to the simulation partitions of the simulated sunshade and the corresponding simulation heat fluxes of the simulation partitions to obtain the simulated external heat flux specifically includes: removing the actual operating orbit conditions from the simulation analysis model; loading the simulation heat loads on the simulation partitions according to the simulation partitions and the corresponding simulation heat fluxes of the simulation partitions, and calculating the second external heat flux from the simulated sunshade at the light inlet; judging the difference between the second external heat flux and the first external heat flux; if the difference between the second external heat flux and the first external heat flux does not meet the first threshold, adjusting the simulation partitions of the sunshade and the simulation heat loads loaded on the corresponding simulation partitions until the first threshold is met.

[0010] Further, change the full size of the simulation light shield to the non-full size, where the length of the non-full size is greater than the diameter of the light incident port of the simulation space camera, specifically including: removing the space environmental conditions in the simulation analysis model, calculating the third external heat flux from the simulation light shield at the light incident port according to the test boundary conditions; judging the difference between the third external heat flux and the second external heat flux; if the difference between the third external heat flux and the second external heat flux does not meet the second threshold, adjust the simulation heat load corresponding to the simulation partition of the simulation light shield according to the simulation partition to compensate for the external heat flux error generated by changing the full size of the simulation light shield to the non-full size.

[0011] Further, establish a ground test analysis model of the test space camera based on the simulation analysis model, specifically including: dividing corresponding test partitions on the test light shield in the ground test analysis model according to the simulation partitions of the simulation light shield; pasting thin-film electric heaters on the test partitions according to the simulation heat fluxes corresponding to the simulation partitions of the simulation light shield to load test heat loads on the test partitions.

[0012] Further, simulate the test external heat flux of the light incident port of the test space camera based on the ground test analysis model, specifically including: controlling the thin-film electric heaters to load test heat loads on the test partitions of the test light shield through a programmable power supply system to achieve the test heat fluxes corresponding to the test partitions; obtaining the test external heat flux of the light incident port of the test space camera; comparing the test external heat flux and the simulation external heat flux to determine the test error.

[0013] Further, before controlling the thin-film electric heaters to load test heat loads on the test partitions through a programmable power supply system to achieve the test heat fluxes corresponding to the test partitions, the method further includes: ensuring that the temperature boundaries of the multi-layer inner surfaces of the test light shield on the side close to the light incident port of the test space camera are close to the temperature boundaries of the multi-layer inner surfaces of the simulation test shield on the side of the light incident port of the simulation space camera.

[0014] Further, before controlling the thin-film electric heaters to load test heat loads on the test partitions through a programmable power supply system to achieve the test heat fluxes corresponding to the test partitions, the method further includes: arranging temperature measurement sensors on the test partitions and arranging heat flux meters at the light incident port of the test space camera.

[0015] Compared with the prior art, the method for simulating the external heat flux of the light inlet of a large-aperture space camera provided by the present invention first establishes a simulation analysis model of a simulated space camera, where the simulated sunshade of the simulated space camera is non-full-size. Then, a ground test analysis model of a test space camera is established based on the simulation analysis model. Finally, the test external heat flux of the light inlet of the test space camera is simulated based on the ground test analysis model. After creatively using a non-full-size sunshade to establish a simulation analysis model, the present invention establishes a ground test analysis model of a test space camera based on the simulation analysis model, solving the problem that the total length of a high-orbit large-aperture space camera and its sunshade is too long, and the size of the ground space environment simulator is limited and cannot be used for ground thermal test verification. It provides an economical, practical and engineering-realizable method for simulating external heat flux for the same type of space cameras and future space cameras with even larger apertures. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 is a flowchart of a method for simulating the external heat flux of the light inlet of a large-aperture space camera provided by an embodiment of the present invention; Figure 2 is Figure 1 a schematic diagram of a simulated space camera in the simulation method shown; Figure 3 is Figure 1 a schematic diagram of a test space camera in the simulation method shown; Figure 4 is a ground test schematic diagram of an experimental space camera using Figure 3 the one shown; Figure 5 is Figure 1 a schematic diagram of the arrangement of heat flux meters in the external heat flux simulation method shown.

[0017] DESCRIPTION OF THE REFERENCE NUMERALS: 1. Simulated sunshade; 2. Simulated space camera; 3. Simulated satellite platform; 1'. Test sunshade; 11'. Heat flux meter; 2'. Test vacuum camera; 3'. Test satellite platform; 4'. Light inlet; 5'. Test external heat flux; 6'. Loading platform; 7'. Vacuum tank door; 8'. Heat sink. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many details are described to enable a better understanding of the present invention. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present invention are not shown or described in the specification, in order to avoid the core part of the present invention being overwhelmed by excessive description. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0019] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in an obvious manner by those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0021] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0022] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0023] As Figure 1 shown, the method for simulating the external heat flux of the light entrance of a large-aperture space camera provided by the present invention includes the following steps: S10: Establish a simulation analysis model of the simulation space camera, where the simulation light shield of the simulation space camera is non-full-size; S20: Based on the simulation analysis model, establish a ground test analysis model of the test space camera; S30: Based on the ground test analysis model, simulate the test external heat flux of the light entrance of the test space camera. It can be seen that the method for simulating the external heat flux of the light entrance of a large-aperture space camera provided by the present invention uses a non-full-size simulation light shield to replace the full-size light shield, solves the problem that the total length of the large-aperture space camera and the light shield is too long and is limited by the size of the space environment simulator and cannot be verified by ground thermal tests, breaks through the size limitations of the large-aperture space camera and the full-size light shield, realizes the simulation of the external heat flux of the light entrance of the large-aperture space camera, and provides an economical and practical and engineerable external heat flux simulation method for the same type of space camera and future larger-aperture space cameras. When no additional tooling is added to the corresponding established ground test analysis model, first establish the simulation analysis model by simulation and then establish the ground test analysis model, which effectively ensures the simulation accuracy of the external heat flux of the ground thermal test.

[0024] Furthermore, as Figure 2 shown, in the method for simulating the external heat flux of the light entrance of a large-aperture space camera provided by the embodiment of the present invention, S10: Establish a simulation analysis model of the simulation space camera, where the simulation light shield of the simulation space camera is non-full-size, and specifically includes: Establish a simulation analysis model according to the full-size of the simulation light shield, calculate the simulation external heat flux of the light entrance of the simulation space camera; Load the simulation heat load on the simulation partition according to the simulation partition of the simulation light shield and the corresponding simulation heat flux of the simulation partition to obtain the simulation external heat flux; Change the full-size of the simulation light shield to non-full-size, and the length of the non-full-size is greater than the diameter of the light entrance of the simulation space camera.

[0025] It can be seen that the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention first establishes a simulation analysis model. In the simulation analysis model, a non-full-size sunshade is used to simulate the transient non-uniformly distributed external heat flux at the light entrance, solving the problem of simulating the external heat flux at the light entrance of the high-orbit large-aperture space camera. When establishing the simulation analysis model, the full-size simulation sunshade is partitioned by simulation analysis, so multiple simulation partitions are formed on the simulation sunshade, and local equivalent heat loads are used for the full-size simulation sunshade to simulate the corresponding simulation heat fluxes on multiple simulation partitions. At the same time, the non-uniformly distributed transient external heat flux received at the light entrance of the simulation sunshade and the effect of the temperature boundary fluctuations on the multi-layer inner surface of the simulation sunshade are simulated, thereby establishing a simulation analysis model of the simulation space camera.

[0026] Furthermore, in the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention, when establishing a simulation analysis model with the simulation sunshade being full-size and calculating the simulation external heat flux at the light entrance of the simulation space camera, it specifically includes: establishing a simulation analysis model with a full-size simulation sunshade based on the main body of the actual space camera, the space environmental conditions it is in, and the actual operating orbit conditions; calculating the transient absorbed external heat flux on the outer surface of the simulation sunshade, the temperature distribution on the inner surface of the simulation sunshade, and the first external heat flux from the simulation sunshade at the light entrance based on the simulation analysis model.

[0027] Establish a simulation analysis model according to the actual operating conditions of the space camera, and correspondingly establish a simulation analysis model for the full-size simulation sunshade. The actual operating conditions of the space camera include the main body of the actual space camera, the space environmental conditions where the actual space camera is located, and the actual operating orbit conditions of the actual space camera. After the simulation analysis model is established, calculate the transient absorbed external heat flux on the outer surface (the side facing the sun irradiation) of the simulation sunshade, the temperature distribution on the inner surface (the side facing away from the sun and facing the light entrance of the simulation space camera), and the first external heat flux transiently arriving at the light entrance from the simulation sunshade through the simulation analysis model.

[0028] Furthermore, in the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention, before loading the simulation heat load on the simulation partition according to the simulation partition of the simulation sunshade and the simulation heat flux corresponding to the simulation partition to obtain the simulation external heat flux, it further includes: partitioning the outer surface of the simulation sunshade based on the principle of similar heat flux density of the transient absorbed external heat flux on the outer surface of the simulation sunshade, and multiplying the heat flux density by the area of the simulation partition to obtain the simulation heat flux corresponding to the simulation partition. Calculate the transient absorbed external heat flux on the outer surface of the simulation sunshade according to the simulation analysis model, partition the simulation sunshade according to the principle of similar heat flux density to obtain the simulation partition, and multiply the heat flux density by the area of the simulation partition to obtain the simulation heat fluxes of each simulation partition.

[0029] Furthermore, in the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention, simulation thermal loads are loaded on the simulation partitions according to the simulation partitions of the simulation sunshade and the corresponding simulation heat fluxes of the simulation partitions to obtain the simulation external heat flux, which specifically includes: removing the actual operating orbit conditions in the simulation analysis model; loading the simulation thermal loads on the simulation partitions according to the simulation partitions and the corresponding simulation heat fluxes of the simulation partitions, and calculating the second external heat flux from the simulation sunshade at the light entrance; judging the difference between the second external heat flux and the first external heat flux; if the difference between the second external heat flux and the first external heat flux does not meet the first threshold, adjusting the simulation partitions of the sunshade and the simulation thermal loads loaded on the corresponding simulation partitions until the first threshold is met.

[0030] Based on the simulation analysis model, the orbit conditions are removed, and thermal load conditions are loaded according to the simulation partitions of the full-size simulation sunshade and the simulation heat fluxes of each simulation partition. The interval duration between the thermal load loading control period and the external heat flux calculation position points of the actual orbit of the actual space camera is matched. The load loading control period can generally be set to several seconds to 1 minute, and the period is very short. The control period is set as a divisor of the external heat flux calculation position point duration to ensure that the value at the calculation point is accurate.

[0031] On the premise that the temperature difference between the simulation partitions on the inner surface of the simulation sunshade for obtaining the first external heat flux and the second external heat flux respectively is less than 5°C, the difference between the first external heat flux and the second external heat flux received by the light entrance of the simulation sunshade is less than 5%. If it does not meet the requirement, return and continue to adjust the simulation partitions of the simulation sunshade and the simulation thermal loads loaded on the simulation partitions in the simulation analysis model until the above conditions are met. The first threshold here can be 5%.

[0032] Furthermore, in the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention, the full size of the simulation sunshade is changed to a non-full size, and the length of the non-full size is greater than the diameter of the light entrance of the simulation space camera, which specifically includes: removing the space environment conditions in the simulation analysis model, and calculating the third external heat flux from the simulation sunshade at the light entrance according to the test boundary conditions; judging the difference between the third external heat flux and the second external heat flux; if the difference between the third external heat flux and the second external heat flux does not meet the second threshold, adjusting the simulation heat loads corresponding to the simulation partitions of the simulation sunshade according to the simulation partitions to compensate for the external heat flux error caused by changing the full size of the simulation sunshade to a non-full size.

[0033] To solve the problem of the ground thermal test of a large-aperture space camera, the embodiments of the present invention use a non-full-size light-shield to simulate the transient arriving external heat flux at the light inlet of the test light-shield in the ground test analysis model, reducing the size limitation of the total length of the actual space camera on the ground space environment simulator. To improve the simulation accuracy of the ground thermal test, a simulation analysis model is established in the simulation stage, and then a ground test analysis model is established according to the simulation analysis model of the non-full-size simulation light-shield.

[0034] On the simulation analysis model, the full-size simulation light-shield is changed to the non-full-size light-shield used in the test. The length of the non-full-size simulation light-shield is greater than the light inlet diameter of the simulation space camera. The simulation partitions of the simulation light-shield remain unchanged, only the space environment conditions in the simulation analysis model are removed, and then the transient arriving external heat flux at the light inlet of the simulation light-shield is calculated according to the test boundary conditions (see the environmental boundaries such as the stage 6' and the heat sink 8' included in Figure 4 . Compare whether the difference between the second external heat flux and the third external heat flux is less than 5%. If not satisfied, adjust the thermal load applied to the simulation partitions on the simulation light-shield, and preferably adjust the thermal load applied to the simulation partitions on the simulation light-shield far from the light inlet. The simulation light-shield is partitioned using the simulation analysis model, and the non-full-size actual light-shield is simulated using local equivalent thermal loads, simultaneously simulating the non-uniformly distributed transient external heat flux received at the light inlet of the actual light-shield and the effect of the temperature boundary fluctuations on the multi-layer inner surface of the actual light-shield, effectively ensuring the simulation accuracy of the external heat flux in the thermal test.

[0035] Furthermore, in the external heat flux simulation method for the light inlet of the large-aperture space camera provided by the embodiments of the present invention, a ground test analysis model of the test space camera is established based on the simulation analysis model, specifically including: dividing corresponding test partitions on the test light-shield in the ground test analysis model according to the simulation partitions of the simulation light-shield; pasting thin-film electric heaters on the test partitions according to the simulation heat fluxes corresponding to the simulation partitions of the simulation light-shield to apply test thermal loads on the test partitions.

[0036] According to the simulation partitions of the simulation sunshade in the simulation analysis model and the thermal loads applied on the simulation partitions, corresponding test partitions are demarcated on the non-full-scale test sunshade in the ground thermal test, and thin-film electric heaters are pasted on the test partitions. By pasting thin-film heaters on the outer surface of the test sunshade to simulate the transient absorbed external heat flux received on the test partitions of the test sunshade, the multi-layer inner surface temperature of the test sunshade is indirectly controlled, and at the same time, it serves as the temperature boundary for the thermal test of the test space camera. To reduce the ground test error, the length of the non-full-scale test sunshade is greater than the diameter of the light entrance of the test space camera. For the error of the transient absorbed external heat flux caused by using a non-full-scale test sunshade instead of a full-scale test sunshade, compensation is preferentially carried out by adjusting the thermal loads of each test partition on the side of the test sunshade far from the light entrance. It should be noted that except for the difference in length between the non-full-scale test sunshade and the actual sunshade, its structural form, material composition, etc. are the same as the actual ones.

[0037] Furthermore, in the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiment of the present invention, the test external heat flux of the light entrance of the test space camera is simulated based on the ground test analysis model, which specifically includes: controlling the thin-film electric heater to apply test thermal loads on the test partitions of the test sunshade through the programmable power supply system to achieve the test heat flux corresponding to the test partitions; obtaining the test external heat flux of the light entrance of the test space camera; comparing the test external heat flux and the simulation external heat flux to determine the test error. No additional tooling is added to the established ground test analysis model, effectively ensuring the simulation accuracy of the external heat flux in the ground thermal test. The programmable power supply system is used to apply transient thermal loads to each test partition, and test thermal loads are simulated and loaded on the test partitions.

[0038] By comparing the simulation analysis model and the test analysis model, the test partitions of the non-full-scale test sunshade and the thermal loads applied on the corresponding test partitions are determined. In the ground test, temperature measurement sensors are arranged on the multi-layer inner surface, and a heat flux meter is arranged at the light entrance of the test sunshade. The simulation external heat flux and the test external heat flux are compared to determine the test error. Through the test error, the effectiveness of the test can be judged, and whether the test results can achieve the correctness and effectiveness of the test verification design can be determined. The simulation model can also be corrected to obtain more accurate simulated prediction temperatures.

[0039] Furthermore, in the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiment of the present invention, before controlling the thin-film electric heater to apply test thermal loads on the test partitions through the programmable power supply system to achieve the test heat flux corresponding to the test partitions, it further includes: arranging temperature measurement sensors on the test partitions and arranging a heat flux meter at the light entrance of the test space camera. During the test, temperature measurement sensors are pasted on the multi-layer inner surface of the test sunshade to measure the temperatures in different regions, and a heat flux meter is set at the light entrance of the test sunshade to measure the transient arriving external heat flux received by the light entrance of the test sunshade.

[0040] Further, in the external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention, before realizing the test heat flux corresponding to the test partition by controlling the thin-film electric heater to load the test heat load in the test partition through the programmable power supply system, it further includes: ensuring that the temperature boundaries of the multi-layer inner surfaces of the test light-shielding cover on the side close to the light entrance of the test space camera are close to the temperature boundaries of the multi-layer inner surfaces of the simulation test cover on the side of the light entrance of the simulation space camera.

[0041] The external heat flux absorbed by the test light-shielding cover is simulated by pasting thin-film electric heaters on the multi-layer outer surfaces of the test light-shielding cover, indirectly controlling the transient arriving external heat flux received at the light entrance of the test light-shielding cover and the temperature boundaries of the multi-layer inner surfaces. For the external heat flux error caused by using a non-full-size test light-shielding cover instead of a full-size one, the heat loads of each test partition on the side of the test light-shielding cover far from the light entrance are adjusted for compensation, and it is ensured that the temperature boundaries of the multi-layer inner surfaces of the light-shielding cover on the side close to the light entrance are basically the same as the actual ones. In addition, the heat capacity and thermal conductivity of the material of the non-full-size test light-shielding cover are the same as those of the actual light-shielding cover, and the changes in the inner surface temperature of the test light-shielding cover and the transient absorbed external heat flux received at the light entrance can be ensured to be basically the same as the actual operating conditions.

[0042] The external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention is described in combination with specific examples. As Figure 2 shown, a large-aperture simulation analysis model involved in the embodiments of the present invention includes a simulation light-shielding cover 1, a simulation space camera 2, and a simulation satellite platform 3. As Figure 3 shown, a half-size test light-shielding cover 1', a simulation space camera 2', and a simulation satellite platform 3' for ground thermal tests. The external heat flux simulation method for the light entrance of the large-aperture space camera provided by the embodiments of the present invention specifically includes the following steps: 1) Establish a simulation analysis model according to the actually used full-size simulation light-shielding cover. The simulation analysis model includes a simulation space camera, space environmental conditions, and actual operating orbit conditions. Calculate the transient absorbed external heat flux on the outer surface (the side facing the sun irradiation) of the simulation light-shielding cover and the temperature distribution on the inner surface (the side facing away from the sun and facing the light entrance of the simulation space camera) of the simulation light-shielding cover. Establish a heat flux meter model at the light entrance of the simulation space camera and calculate the transient arriving external heat flux from the simulation light-shielding cover. The position of the heat flux meter model is the same as that of the thermal test, as Figure 5 shown.

[0043] 2) Calculate the transient absorbed external heat flux on the outer surface of the simulated sunshade according to the simulation analysis model. Divide the simulated sunshade into zones according to the principle of similar heat flux density to obtain the simulated zones. Multiply the heat flux density by the area of the simulated zone to obtain the external heat flux of each simulated zone. Remove the orbital conditions from the simulation analysis model, and apply the heat load conditions according to the simulated zones of the simulated sunshade and the external heat flux of each simulated zone. The time interval between the calculation position points of the external heat flux of the simulated zones on the actual orbit can be 30 min, and the loading control period of the heat load is set at 10 min. During actual operation, the change in the external heat flux of the actual sunshade before and after entering and leaving the earth's shadow area is drastic, and during this period, the loading control period of the heat load can be controlled at 3 min.

[0044] 3) Compare whether the difference between the first external heat flux and the second external heat flux, which is the transient arriving external heat flux received by the light inlet of the simulated sunshade from the simulated sunshade, is less than 5% when the temperature difference between the simulated zones on the inner surface of the simulated sunshade before and after removing the orbital conditions is less than 5°C. If not satisfied, adjust the simulated zones of the simulated sunshade and the heat load of the corresponding simulated zones in the simulation analysis model. For example, after removing the orbital conditions, a total of 178 simulated zones are divided on the multi-layer outer surface of the simulated sunshade. The maximum temperature difference between the simulated zones on the inner surface of the simulated sunshade is 3.4°C, and the maximum difference between the first external heat flux and the second external heat flux, which is the transient arriving external heat flux at the light inlet of the simulated sunshade, is 3.1%.

[0045] 4) Then, based on the simulation analysis model, change the full-size simulated sunshade to a half-size test sunshade for testing. The length of the test sunshade is about 1.1 times the diameter of the light inlet of the test space camera. The simulated zones of the half-size simulated sunshade remain unchanged, with a total of 98 simulated zones. Remove the environmental conditions, and calculate the transient arriving external heat flux at the light inlet of the simulated sunshade according to the test boundary conditions (including environmental boundaries such as the stage 6' and the heat sink 8'). The ground heat test plan is as Figure 4 shown, and the test boundary conditions are set according to Figure 4 the settings.

[0046] 5) Check whether the difference between the second external heat flux and the third external heat flux, which is the transient arriving external heat flux received by the light inlet of the simulated sunshade from the simulated sunshade, is less than 5%. If not satisfied, adjust the heat load applied to the simulated zones of the simulated sunshade in the simulation analysis model, and preferably adjust the heat load applied to the simulated zones on the simulated sunshade far from the light inlet. After analysis, the maximum difference between the first external heat flux and the second external heat flux is 3.5%. The heat load applied to the simulated zones on the side of the simulated sunshade close to the light inlet remains unchanged, and the heat load applied to each simulated zone on the side of the simulated sunshade far from the light inlet is increased. A total of 40 simulated zones have their applied heat loads changed; 6) Divide the test zones on the multi-layer outer surface of the half-scale test baffle in the ground thermal test and paste thin-film electric heaters on the corresponding test zones according to the simulation zones of the simulation baffle in the simulation analysis model and the thermal loads applied on the corresponding simulation zones. Control the thin-film electric heaters on each test zone through the programmable power supply system to simulate the applied thermal loads. In the ground test, paste temperature sensors on the multi-layer inner surface of the test baffle to measure the regional temperatures of different test zones, and set a heat flux meter at the light inlet of the test baffle to measure the transient arriving external heat flux received at the light inlet, as Figure 5 shown. Compare the test analysis model with the simulation analysis model, and the maximum difference between the transient arriving external heat flux at the light inlet, i.e., the test external heat flux and the simulation external heat flux, is 4.7%.

[0047] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in the disclosure of the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and no limitation is made herein.

[0048] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for simulating external heat flow at a large-aperture space camera light entrance, characterized in that: The following steps are involved: Establishing a simulation analysis model of a simulated space camera, wherein the simulated light shield of the simulated space camera is non-full-size; Establishing a ground test analysis model of the test space camera based on the simulation analysis model; The test external heat flow at the light entrance of the test space camera is simulated based on the ground test analysis model.

2. The external heat flow simulation method according to claim 1, characterized in that: A simulation analysis model of a simulated space camera is established, wherein the simulated light shield of the simulated space camera is not full-size, specifically including: Establishing the simulation analysis model in full size according to the simulated light shield, and calculating the simulated external heat flux of the light entrance of the simulated space camera; Loading a simulated heat load on the simulated partition according to the simulated partition of the simulated light shield and the simulated heat flow corresponding to the simulated partition to obtain the simulated external heat flow; The full size of the simulated light shield is changed to the non-full size, and the length of the non-full size is greater than the diameter of the light entrance of the simulated space camera.

3. The external heat flow simulation method according to claim 2, characterized in that: The simulation analysis model is established in full size according to the simulated light shield, and the simulated external heat flux of the light entrance of the simulated space camera is calculated, specifically including: The simulation analysis model having the simulated light shield in full size is established based on the main body of the actual space camera, the space environment conditions and the actual running orbit conditions; The transient absorbed external heat flux on the outer surface of the simulated light shield, the temperature distribution on the inner surface of the simulated light shield, and the first external heat flux from the simulated light shield at the light entrance are calculated based on the simulation analysis model.

4. The external heat flow simulation method according to claim 3, characterized in that: Before loading a simulated heat load on the simulated partition according to the simulated partition of the simulated light shield and the simulated heat flow corresponding to the simulated partition to obtain the simulated external heat flow, the method further includes: The outer surface of the simulated light shield is divided into the simulated partitions based on the principle of similar heat flux density of transiently absorbed external heat flux on the outer surface of the simulated light shield, and the simulated heat flux corresponding to the simulated partition is obtained by multiplying the heat flux density with the area of ​​the simulated partition.

5. The external heat flow simulation method according to claim 4, characterized in that: According to the simulated partitions of the simulated light shield and the simulated heat flows corresponding to the simulated partitions, a simulated heat load is loaded on the simulated partitions to obtain the simulated external heat flows, specifically comprising: removing the actual running track condition in the simulation analysis model; Loading a simulated heat load on the simulated partition according to the simulated partition and the simulated heat flow corresponding to the simulated partition, calculating a second external heat flow from the simulated light shield at the light entrance; determining a difference between the second external heat flow and the first external heat flow; If the difference between the second external heat flux and the first external heat flux does not meet the first threshold, the simulation partition of the light shield and the simulation heat load loaded on the corresponding simulation partition are adjusted until the first threshold is met.

6. The external heat flow simulation method according to claim 5, characterized in that: Changing the full size of the simulated light shield to the non-full size, wherein the length of the non-full size is greater than the diameter of the light entrance of the simulated space camera, specifically includes: The spatial environment condition in the simulation analysis model is removed, and a third external heat flux from the simulation light shield at the light entrance is calculated according to the experimental boundary condition; determining a difference between the third external heat flow and the second external heat flow; If the difference between the third external heat flux and the second external heat flux does not meet the second threshold, the simulated heat load corresponding to the simulated partition is adjusted for the simulated light shield according to the simulated partition to compensate for the external heat flux error caused by changing the full size of the simulated light shield to the non-full size.

7. The external heat flow simulation method according to any one of claims 2 to 6, characterized in that: A ground test analysis model for the test space camera is established based on the simulation analysis model, specifically including: Dividing corresponding test partitions on the test light shield in the ground test analysis model according to the simulation partitions of the simulation light shield; A thin-film electric heater is attached to the test partition according to the simulated heat flow corresponding to the simulated partition of the simulated shading cover, so as to load a test heat load on the test partition.

8. The external heat flow simulation method according to claim 7, characterized in that: The method of simulating the test external heat flow of the light entrance of the test space camera based on the ground test analysis model specifically includes: Controlling the thin-film electric heater to load a test heat load on a test partition of the test light shield through a programmable power supply system to achieve a test heat flow corresponding to the test partition; Acquiring an experimental external heat flux at a light entrance of the experimental space camera; The experimental external heat flow is compared with the simulated external heat flow to determine the experimental error.

9. The external heat flow simulation method according to claim 8, characterized in that: Before controlling the thin-film electric heater to load a test heat load on the test partition through a programmable power supply system to achieve a test heat flow corresponding to the test partition, the method further includes: Ensure that the temperature boundary of the multi-layer inner surface of the test light shield near the light entrance of the test space camera is close to the temperature boundary of the multi-layer inner surface of the simulation test cover near the light entrance of the simulation space camera.

10. The external heat flow simulation method according to claim 8, characterized in that: Before controlling the thin-film electric heater to load a test heat load on the test partition through a programmable power supply system to achieve a test heat flow corresponding to the test partition, the method further includes: A temperature sensor is arranged on the test partition, and a heat flux meter is arranged at the light entrance of the test space camera.

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