A method for simulating external heat flux at the light entrance of a large-aperture space camera

Abstract

The present invention relates to the field of spacecraft thermal control technology, and in particular to a method for simulating external heat flow at the light entrance of a large-aperture space camera. This method comprises the following steps: 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-based test analysis model of a test space camera based on the simulation analysis model; and simulating the test external heat flow at the light entrance of the test space camera based on the ground-based test analysis model. This method overcomes the size limitations of large-aperture space cameras and full-size light shields, enabling simulation of external heat flow at the light entrance of a large-aperture space camera.

Description

Technical Field

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

[0002] Thermal control is a key technology for ensuring the imaging quality of space cameras. Thermal deformation caused by changes in external heat flux during on-orbit is a key factor influencing camera imaging performance. Appropriate thermal control measures are required to maintain the camera's temperature level and temperature gradient. Accurate simulation of external heat flux during ground-based testing determines the effectiveness of ground-based verification of thermal control for space cameras.

[0003] For large-aperture space cameras in geostationary orbit, a beveled sunshade is typically designed at the light entrance to prevent direct sunlight from entering the camera's optical system, thereby avoiding temperature disturbances in the camera's optomechanical structure and high-temperature damage to components such as detectors. The length of the sunshade is related to the camera's aperture and sunlight avoidance strategy, and can reach over ten meters. However, for ground-based thermal testing of large-aperture space cameras, the combined length of the camera and sunshade is over ten meters, making it impossible to conduct tests using a full-size sunshade due to the size of the space environment simulator. Furthermore, the number of electric heaters and the amount of wire bonding required to simulate the absorption of external heat flux using a full-size sunshade are enormous, making it difficult to implement a longer full-size sunshade for future larger-aperture space cameras. Therefore, overcoming the size limitations of large-aperture space cameras and full-size sunshades to simulate heat flux outside the light entrance of large-aperture space cameras has become an urgent issue. Summary of the Invention

[0004] In view of this, the present invention aims to provide a method for simulating the external heat flow of the light entrance of a large-aperture space camera, breaking through the size limitations of large-aperture space cameras and full-size light shields, and realizing the simulation of the external heat flow of the light entrance of a large-aperture space camera.

[0005] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0006] The present invention provides a method for simulating the external heat flow of a light entrance of a large-aperture space camera, comprising the following steps: establishing a simulation analysis model of a simulation space camera, wherein a simulation light shield of the simulation space camera is non-full-size; establishing a ground test analysis model of an experimental space camera based on the simulation analysis model; and simulating the experimental external heat flow of the light entrance of the experimental space camera based on the ground test analysis model.

[0007] Furthermore, a simulation analysis model of a simulation space camera is established, wherein the simulation light shield of the simulation space camera is non-full-size, specifically including: establishing the simulation analysis model according to the simulation light shield as full-size, and calculating the simulated external heat flux of the light entrance of the simulation space camera; loading a simulated heat load on the simulation partition according to the simulation partition of the simulation light shield and the simulated heat flow corresponding to the simulation partition to obtain the simulated external heat flow; changing the full size of the simulation light shield to the 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.

[0008] Furthermore, the simulation analysis model is established according to the full-size simulation light shield, and the simulated external heat flux of the light entrance of the simulated space camera is calculated, specifically including: establishing the simulation analysis model with the full-size simulation light shield 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 simulation light shield, the temperature distribution on the inner surface of the simulation light shield, and the first external heat flux from the simulation light shield at the light entrance based on the simulation analysis model.

[0009] Furthermore, 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 also includes: dividing the outer surface of the simulated light shield into the simulated partitions based on the principle of similar heat flux density of the transiently absorbed external heat flow on the outer surface of the simulated light shield, and multiplying the heat flux density by the area of the simulated partition to obtain the simulated heat flow corresponding to the simulated partition.

[0010] Furthermore, a simulated heat load is loaded 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, specifically including: removing the actual operating track conditions in the simulation analysis model; loading a simulated heat load on the simulation partition according to the simulation partition and the simulated heat flow corresponding to the simulation partition, and calculating the second external heat flow from the simulated light shield at the light entrance; judging the difference between the second external heat flow and the first external heat flow; if the difference between the second external heat flow and the first external heat flow does not meet the first threshold, adjusting the simulated partition of the light shield and the simulated heat load loaded on the corresponding simulation partition until the first threshold is met.

[0011] Furthermore, 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, specifically including: removing the space environment conditions in the simulation analysis model, and calculating the third external heat flux from the simulated light shield at the light entrance according to the experimental 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 simulated heat load corresponding to the simulation partition of the simulated light shield according to the simulation 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.

[0012] Furthermore, 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; and pasting a thin film electric heater on the test partition according to the simulation heat flow corresponding to the simulation partition of the simulation light shield to load the test heat load on the test partition.

[0013] Furthermore, based on the ground test analysis model, the test external heat flow of the light entrance of the test space camera is simulated, specifically including: controlling the thin film electric heater to load the test heat load on the test partition of the test light shield through the programmable power supply system to realize the test heat flow corresponding to the test partition; obtaining the test external heat flow of the light entrance of the test space camera; comparing the test external heat flow and the simulated external heat flow to determine the test error.

[0014] Furthermore, before the thin-film electric heater is controlled by a programmable power supply system to load a test heat load in the test partition to realize the test heat flow corresponding to the test partition, the method also includes: ensuring that the temperature boundary of the multi-layer inner surface of the test light shield on the side of 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 on the side of the light entrance of the simulation space camera.

[0015] Furthermore, before controlling the thin-film electric heater to load the test heat load in the test partition through the programmable power supply system to realize the test heat flow corresponding to the test partition, the method also includes: arranging a temperature sensor on the test partition and arranging a heat flux meter at the light entrance of the test space camera.

[0016] Compared with the prior art, the method for simulating external heat flow at the light entrance of a large-aperture space camera provided by the present invention first establishes a simulation analysis model of the simulated space camera, wherein the simulated light shield of the simulated space camera is non-full-size. Then, a ground test analysis model of the experimental space camera is established based on the simulation analysis model. Finally, the experimental external heat flow at the light entrance of the experimental space camera is simulated based on the ground test analysis model. The present invention creatively uses a non-full-size light shield to establish a simulation analysis model, and then establishes a ground test analysis model of the experimental space camera based on the simulation analysis model. This solves the problem that the combined length of a high-orbit large-aperture space camera and its light shield is too long, while the size of a ground space environment simulator is limited and cannot be used for ground thermal test verification. This provides an economical, practical, and engineering-implementable external heat flow simulation method for similar space cameras and future larger-aperture space cameras. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 A flow chart of a method for simulating external heat flow at the light entrance of a large-aperture space camera provided by an embodiment of the present invention;

[0019] Figure 2 for Figure 1 Schematic diagram of the simulated space camera in the simulation method shown;

[0020] Figure 3 for Figure 1 Schematic diagram of the experimental space camera in the simulation method shown;

[0021] Figure 4 To adopt Figure 3 Schematic diagram of the ground test of the experimental space camera shown;

[0022] Figure 5 for Figure 1 Schematic diagram of the arrangement of heat flow meters in the external heat flow simulation method shown.

[0023] Description of reference numerals:

[0024] 1. Simulated light shield; 2. Simulated space camera; 3. Simulated satellite platform; 1', experimental light shield; 11', heat flux meter; 2', experimental vacuum camera; 3', experimental satellite platform; 4', light inlet; 5', experimental external heat flux; 6', loading platform; 7', vacuum tank door; 8', heat sink. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 use associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present invention to be better understood. 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, or methods. In some cases, some operations related to the present invention are not shown or described in the specification. This is to avoid the core part of the present invention being overwhelmed by too much description. For those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0026] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other to form various implementation methods. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various orders in the description and the drawings are only for the purpose of clearly describing a certain embodiment and are not intended to be a required order, unless otherwise specified that a certain order must be followed.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are 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 cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0030] like Figure 1 As shown, the method for simulating external heat flow at the light entrance of a large-aperture space camera provided by the present invention includes the following steps: S10: establishing a simulation analysis model of a simulated space camera, wherein the simulated light shield of the simulated space camera is non-full-size; S20: establishing a ground test analysis model of a test space camera based on the simulation analysis model; and S30: simulating the test external heat flow at the light entrance of the test space camera based on the ground test analysis model. It can be seen that the method for simulating external heat flow at the light entrance of a large-aperture space camera provided by the present invention uses a non-full-size simulated light shield instead of a full-size light shield, solving the problem that the combined length of the large-aperture space camera and the light shield is too long to be verified by ground thermal testing due to the size limitation of the space environment simulator. This method breaks through the size limitation of the large-aperture space camera and the full-size light shield, realizes the simulation of external heat flow at the light entrance of the large-aperture space camera, and provides an economical, practical, and engineering-implementable external heat flow simulation method for similar space cameras and future larger-aperture space cameras. When no additional tooling is added to the corresponding established ground test analysis model, the simulation analysis model is first established by simulation and then the ground test analysis model is established, which effectively ensures the simulation accuracy of the external heat flow of the ground thermal test.

[0031] Furthermore, if Figure 2 As shown, in the external heat flow simulation method of the light entrance of a large-aperture space camera provided by an embodiment of the present invention, S10: establishing a simulation analysis model of a simulated space camera, wherein the simulated light shield of the simulated space camera is non-full-size, specifically including: establishing a simulation analysis model according to the simulated light shield as full-size, and calculating the simulated external heat flow 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; changing the full size of the simulated light shield to a 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.

[0032] It can be seen that the external heat flow simulation method for the light entrance of a large-aperture space camera provided by an embodiment of the present invention first establishes a simulation analysis model. In the simulation analysis model, a non-full-size light shield is used to simulate the transient non-uniformly distributed external heat flow at the light entrance, thereby solving the external heat flow simulation problem of the light entrance of a high-orbit large-aperture space camera. When establishing the simulation analysis model, the full-size simulated light shield is partitioned using simulation analysis, thereby forming multiple simulation partitions on the simulated light shield, and the full-size simulated light shield is subjected to local equivalent thermal loads to simulate the corresponding simulated heat flows on the multiple simulation partitions. At the same time, the effects of the non-uniformly distributed transient external heat flow received at the light entrance of the simulated light shield and the temperature boundary fluctuations of the multi-layer inner surface of the simulated light shield are simulated, thereby establishing a simulation analysis model of the simulated space camera.

[0033] Furthermore, in the external heat flux simulation method for the light entrance of a large-aperture space camera provided in an embodiment of the present invention, a simulation analysis model is established with the simulated light shield as full size, and the simulated external heat flux of the light entrance of the simulated space camera is calculated, specifically including: establishing a simulation analysis model with the simulated light shield as full size based on the main body of the actual space camera, the space environment conditions in which it is located, and the actual operating orbit conditions; calculating 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 based on the simulation analysis model.

[0034] A simulation analysis model was established based on the actual operating conditions of the space camera, and a corresponding simulation analysis model was established for a full-scale simulated sunshade. The actual operating conditions of the space camera include the actual space camera body, the space environment conditions in which the actual space camera is located, and the actual operating orbit conditions of the actual space camera. After the simulation analysis model was established, the transient external heat flux absorbed by the outer surface of the simulated sunshade (the side facing the sun), the temperature distribution on the inner surface of the simulated sunshade (the side facing away from the sun and facing the light entrance of the simulated space camera), and the first external heat flux transiently received by the light entrance from the simulated sunshade.

[0035] Furthermore, in the external heat flow simulation method for the light entrance of a large-aperture space camera provided in an embodiment of the present invention, before loading a simulated heat load on the simulated partitions of the simulated light shield according to the simulated partitions of the simulated light shield and the simulated heat flows corresponding to the simulated partitions to obtain the simulated external heat flows, the method further includes: dividing the outer surface of the simulated light shield into simulated partitions based on the principle of similar heat flux density of transient external heat flows absorbed on the outer surface of the simulated light shield, and multiplying the heat flux density by the area of the simulated partitions to obtain the simulated heat flows corresponding to the simulated partitions. The transient external heat flows absorbed on the outer surface of the simulated light shield are calculated according to a simulation analysis model, the simulated light shield is partitioned according to the principle of similar heat flux density to obtain simulated partitions, and the heat flux density is multiplied by the area of the simulated partitions to obtain the simulated heat flows of each simulated partition.

[0036] Furthermore, in the external heat flow simulation method for the light entrance of a large-aperture space camera provided in an embodiment of the present invention, a simulated heat load is loaded 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 a simulated external heat flow, specifically including: removing the actual operating orbit conditions in the simulation analysis model; loading the simulated heat load on the simulated partition according to the simulated partition and the simulated heat flow corresponding to the simulation partition, and calculating the second external heat flow from the simulated light shield at the light entrance; judging the difference between the second external heat flow and the first external heat flow; if the difference between the second external heat flow and the first external heat flow does not meet the first threshold, adjusting the simulated partition of the light shield and the simulated heat load loaded on the corresponding simulation partition until the first threshold is met.

[0037] Based on the simulation analysis model, orbital conditions were removed. Heat load conditions were applied according to the simulated partitions of the full-scale simulated sunshade and the simulated heat flow of each partition. The heat load control period was matched to the duration of the external heat flow calculation points on the actual orbit of the actual space camera. The load load control period can generally be set to a short period of several seconds to 1 minute. The control period is set to a divisor of the duration of the external heat flow calculation point to ensure accurate values at the calculation point.

[0038] Under the premise that the temperature difference between the simulated subareas on the inner surface of the simulated light shield, which respectively generate the first and second external heat flows, is less than 5°C, the difference between the first and second external heat flows received by the simulated light shield at the light inlet must be less than 5%. If this condition is not met, the simulation analysis model will continue to adjust the simulated subareas of the simulated light shield and the simulated heat loads applied to these subareas until the above condition is met. The first threshold here can be 5%.

[0039] Furthermore, in the external heat flow simulation method for the light entrance of a large-aperture space camera provided in an embodiment of the present invention, the full size of the simulated light shield 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 simulated space camera. Specifically, the method includes: removing the space environment conditions in the simulation analysis model, and calculating the third external heat flow from the simulated light shield at the light entrance according to the experimental boundary conditions; judging the difference between the third external heat flow and the second external heat flow; if the difference between the third external heat flow and the second external heat flow does not meet the second threshold, adjusting the simulated heat load corresponding to the simulated partition of the simulated light shield according to the simulation partition to compensate for the external heat flow error caused by changing the full size of the simulated light shield to the non-full size.

[0040] To address ground-based thermal testing of large-aperture space cameras, the present invention employs a non-full-scale sunshade to simulate the transient external heat flux at the light entrance of the test sunshade in the ground-based test analysis model. This reduces the overall length of the actual space camera's limitations on the size of the ground-based space environment simulator. To improve the accuracy of ground-based thermal testing, the simulation analysis model is established during the simulation phase, and then the ground-based test analysis model is established based on the simulation analysis model of the non-full-scale simulated sunshade.

[0041] In the simulation analysis model, the full-size simulation light shield is changed to the non-full-size light shield used in the experiment. The length of the non-full-size simulation light shield is larger than the diameter of the light entrance of the simulation space camera. The simulation partition of the simulation light shield remains unchanged. Only the space environment conditions in the simulation analysis model are removed, and then the experimental boundary conditions (see Figure 4 The transient external heat flux arriving at the light entrance of the simulated light shield is calculated based on the environmental boundaries (including the stage 6', heat sink 8', etc.). The difference between the second external heat flux and the third external heat flux is compared to see if it is less than 5%. If not, the heat load loaded on the simulated partition of the simulated light shield is adjusted, with priority given to adjusting the heat load loaded on the simulated partition of the simulated light shield away from the light entrance. The simulated light shield is partitioned using a simulation analysis model, and the local equivalent heat load is simulated for the actual light shield that is not full-size. At the same time, the non-uniformly distributed transient external heat flux received at the light entrance of the actual light shield is simulated, as well as the effect of the temperature boundary fluctuation of the multi-layer inner surface of the actual light shield, effectively ensuring the simulation accuracy of the external heat flux of the thermal test.

[0042] Furthermore, in the external heat flow simulation method of the light entrance of a large-aperture space camera provided in an embodiment 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; and pasting a thin-film electric heater on the test partition according to the simulated heat flow corresponding to the simulation partition of the simulation light shield to load the test heat load on the test partition.

[0043] The non-full-scale test light shield used in the ground thermal test was divided into corresponding test zones based on the simulated zones and the heat loads applied to the simulated zones in the simulation analysis model. Thin-film electric heaters were attached to the outer surface of the test light shield to simulate the transient external heat flux received by the test zones, indirectly controlling the temperature of the multiple internal surfaces of the test light shield and serving as the temperature boundary for the thermal testing of the test space camera. To minimize ground test errors, the length of the non-full-scale test light shield was greater than the diameter of the light entrance of the test space camera. Errors in transient external heat flux caused by using the non-full-scale test light shield in place of the full-scale test light shield were primarily compensated by adjusting the heat loads on the test zones on the side of the test light shield away from the light entrance. It should be noted that, except for the length, the non-full-scale test light shield's structure and material composition were consistent with the actual light shield.

[0044] Furthermore, in the method for simulating the external heat flow at the light entrance of a large-aperture space camera provided by an embodiment of the present invention, the test external heat flow at the light entrance of the test space camera is simulated based on a ground test analysis model, specifically including: controlling the thin-film electric heater to load the test heat load in the test partition of the test light shield through a programmable power supply system to achieve the test heat flow corresponding to the test partition; obtaining the test external heat flow at the light entrance of the test space camera; comparing the test external heat flow with the simulated external heat flow to determine the test error. No additional tooling is added to the corresponding established ground test analysis model, effectively ensuring the simulation accuracy of the external heat flow of the ground thermal test. Transient heat load is applied to each test partition through a programmable power supply system, and the loading of the test heat load is simulated on the test partition.

[0045] By comparing the simulation analysis model with the experimental analysis model, the test partitions of the non-full-scale test light shield and the heat loads applied to the corresponding test partitions were determined. During the ground test, temperature sensors were placed on multiple internal surfaces and heat flux meters were placed at the light entrance of the test light shield. The simulated external heat flux was compared with the experimental external heat flux to determine the test error. The test error can be used to determine the validity of the test and whether the test results meet the accuracy and effectiveness of the test verification design. The simulation model can also be modified to obtain more accurate simulation temperature predictions.

[0046] Furthermore, in the method for simulating external heat flux at the light entrance of a large-aperture space camera provided in an embodiment of the present invention, before a programmable power supply system is used to control a thin-film electric heater to load a test heat load in a test partition and achieve a test heat flux corresponding to the test partition, the method further includes: arranging temperature sensors on the test partition and arranging a heat flux meter at the light entrance of the test space camera. During the experiment, temperature sensors are attached to the multi-layer inner surface of the test light shield to measure the temperature of different areas, and a heat flux meter is placed at the light entrance of the test light shield to measure the transient external heat flux received by the light entrance of the test light shield.

[0047] Furthermore, in the external heat flow simulation method of the light entrance of a large-aperture space camera provided in an embodiment of the present invention, before the test heat load is loaded in the test partition by controlling the thin-film electric heater through a programmable power supply system to realize the test heat flow corresponding to the test partition, it also includes: ensuring that the temperature boundary of the multi-layer inner surface of the test light shield on the side of 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 on the side of the light entrance of the simulation space camera.

[0048] By attaching thin-film electric heaters to the multi-layer outer surfaces of the test light shield to simulate the external heat flux absorbed by the test light shield, the transient external heat flux received at the light inlet of the test light shield and the temperature boundary of the multi-layer inner surface are indirectly controlled. The external heat flux error caused by using a sub-scale test light shield instead of a full-scale test light shield is compensated by adjusting the thermal load of each test partition on the side of the test light shield away from the light inlet, and ensuring that the temperature boundary of the multi-layer inner surface of the light shield near the light inlet is basically consistent with the actual temperature. In addition, the heat capacity and thermal conductivity of the sub-scale test light shield material are consistent with those of the actual light shield. Therefore, the changes in the test light shield's inner surface temperature and the changes in the transient external heat flux received at the light inlet are basically consistent with actual operating conditions.

[0049] The external heat flow simulation method of the large-aperture space camera light entrance provided by the embodiment of the present invention is described with reference to a specific example. Figure 2 As shown, a large-aperture simulation analysis model involved in an embodiment of the present invention includes a simulation sunshade 1, a simulation space camera 2, and a simulation satellite platform 3. Figure 3 The half-size test light shield 1', simulated space camera 2', and simulated satellite platform 3' for ground thermal testing are shown. The method for simulating the external heat flow of a large-aperture space camera light entrance provided by the embodiment of the present invention specifically includes the following steps:

[0050] 1) Establish a simulation analysis model based on the full-size simulation sunshade actually used. The simulation analysis model includes the simulation space camera, space environment conditions and actual operation orbit conditions. Calculate the transient external heat flux absorbed by the outer surface of the simulation sunshade (the side facing the sun) and the temperature distribution of the inner surface of the simulation sunshade (the side facing away from the sun and facing the light entrance of the simulation space camera). Establish a heat flux meter model at the light entrance of the simulation space camera and calculate the transient external heat flux from the simulation sunshade. The position of the heat flux meter model is consistent with the thermal test, such as Figure 5 shown.

[0051] 2) Calculate the transient external heat flux absorbed by the outer surface of the simulated sunshade based on the simulation analysis model, and partition the simulated sunshade according to the principle of similar heat flux density to obtain simulated partitions. Multiply the heat flux density by the area of the simulated partition to obtain the external heat flux of each simulated partition. Remove the track conditions based on the simulation analysis model, and apply the heat load conditions according to the simulated partitions of the simulated sunshade and the external heat flux of each simulated partition. The interval between the external heat flux calculation position points of the simulated partitions on the actual track can be 30 minutes, and the heat load loading control cycle is set to 10 minutes. During actual operation, the external heat flux of the actual sunshade changes dramatically before and after entering and exiting the ground shadow area. During this period, the heat load loading control cycle can be controlled to 3 minutes.

[0052] 3) Compare the temperature differences between the simulated zones on the inner surface of the simulated light shield before and after the removal of the track condition. When the temperature difference is less than 5°C, check whether the difference between the transient external heat fluxes (i.e., the first and second external heat fluxes) received by the light inlet of the simulated light shield is less than 5%. If this is not the case, adjust the simulated zones of the simulated light shield and the heat loads of the corresponding zones in the simulation analysis model. For example, after removing the track condition, the simulated light shield's multi-layered outer surface is divided into 178 zones. The maximum temperature difference between the simulated zones on the inner surface of the simulated light shield is 3.4°C, and the maximum difference between the transient external heat fluxes (i.e., the first and second external heat fluxes) received by the light inlet of the simulated light shield is 3.1%.

[0053] 4) Based on the simulation analysis model, the full-size simulated light shield was then replaced with a half-size experimental light shield for testing. The length of the experimental light shield was approximately 1.1 times the diameter of the light entrance of the test space camera. The simulation partitions of the half-size simulated light shield remained unchanged, with a total of 98 simulation partitions. The environmental conditions were removed, and the transient heat flux from the light entrance of the simulated light shield was calculated according to the test boundary conditions (including the environmental boundaries such as the stage 6' and the heat sink 8'). The ground thermal test plan is as follows: Figure 4 As shown, the test boundary conditions are as follows Figure 4 set up.

[0054] 5) The transient external heat fluxes received from the simulated light shield at the light inlet, namely the second and third external heat fluxes, differ by less than 5%. If this is not the case, the heat loads applied to the simulated light shield's simulated partitions in the simulation analysis model are adjusted, with priority given to the simulated partitions away from the light inlet. Analysis shows that the maximum difference between the first and second external heat fluxes is 3.5%. The heat load applied to the simulated partitions near the light inlet of the simulated light shield remains unchanged, while the heat loads applied to the simulated partitions away from the light inlet of the simulated light shield are increased. A total of 40 simulated partitions have their heat loads adjusted.

[0055] 6) According to the simulated partitions of the simulated light shield in the simulation analysis model and the heat loads applied to the corresponding simulated partitions, the multi-layer outer surface of the half-scale test light shield of the ground thermal test is divided into test partitions and thin-film electric heaters are attached to the corresponding test partitions. The thin-film electric heaters on each test partition are controlled by a programmable power supply system to simulate the applied heat load. In the ground test, temperature sensors are attached to the multi-layer inner surface of the test light shield to measure the regional temperature of different test partitions, and a heat flux meter is set on the light inlet of the test light shield to measure the transient external heat flux received at the light inlet, such as Figure 5 Comparing the experimental analysis model with the simulation analysis model, the maximum difference between the transient external heat flux at the light entrance, that is, the experimental external heat flux and the simulated external heat flux, is 4.7%.

[0056] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved. This is not limited herein.

[0057] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for simulating external heat flow at the light entrance of a large-aperture space camera, characterized by: 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 not full-size, specifically including: Establishing the simulation analysis model according to the full-scale simulation light shield, and calculating the simulated external heat flux at the light entrance of the simulated space camera, specifically comprising: establishing the simulation analysis model with the full-scale simulation light shield based on the main body of the actual space camera, the space environment conditions in which it is located, and the actual operating orbit conditions, and calculating the transient absorbed external heat flux on the outer surface of the simulation light shield, the temperature distribution on the inner surface of the simulation light shield, and the first external heat flux from the simulation light shield at the light entrance based on the simulation analysis model; 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, specifically including: removing the actual operating 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 simulation 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, and if the difference between the second external heat flow and the first external heat flow does not meet a first threshold, adjusting the simulated partition of the light shield and the simulated heat load loaded on the corresponding simulation partition until the first threshold is met; 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 comprising: removing the space environment condition in the simulation analysis model, calculating the third external heat flux from the simulated light shield at the light entrance 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 a second threshold, adjusting the simulated heat load corresponding to the simulated partition of 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; 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: Before applying 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 by the area of the simulated partition.

3. The external heat flow simulation method according to claim 2, 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 light shield, so as to load a test heat load on the test partition.

4. The external heat flow simulation method according to claim 3, characterized in that: The method of simulating the test external heat flow at 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 the 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 a test external heat flux at a light entrance of the test space camera; The experimental external heat flow is compared with the simulated external heat flow to determine the experimental error.

5. The external heat flow simulation method according to claim 4, 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 test light shield near the light entrance of the simulation space camera.

6. The external heat flow simulation method according to claim 4, 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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