An ultra-low earth orbit satellite whole-process coupling thermal simulation method and system

Abstract

The application provides a kind of ultra-low orbit satellite whole process coupling thermal simulation method and system.The method comprises: constructing whole process coupling thermal simulation system;In control layer, the geometric grid file and orbit attitude parameter file of satellite are imported by input setting interface, and simulation time and task flow time sequence are set;The control layer passes the imported parameters to the calculation layer, and starts time iteration calculation;In the calculation layer, three calculation modules are coupled, and the calculation results are transmitted to the data layer for integration;The data layer transmits the integrated data file to the output display interface to show the simulation results in the form of numerical value, curve or cloud picture.The ultra-low orbit satellite whole process coupling thermal simulation method proposed by the application constructs an integrated thermal simulation system that integrates multiple core calculation modules, while supporting numerical, curve, cloud picture and other forms of visual output, which facilitates designers to intuitively and comprehensively evaluate the satellite thermal management effect.

Description

Technical Field

[0001] This invention relates to the field of spacecraft thermal control technology, specifically to a method and system for full-process coupled thermal simulation of ultra-low orbit satellites. Background Technology

[0002] Ultra-low Earth Orbit (ULEO) typically refers to Earth orbit with an altitude between 100 and 300 kilometers. Satellites operating in this orbital region, i.e., ULEO satellites, have significant advantages such as high observation resolution, short communication latency, and low launch costs. Therefore, they are considered a new approach for future space missions such as Earth observation, scientific exploration, and rapid response, and are attracting widespread attention from many countries, gradually becoming a research hotspot in space technology.

[0003] Very low Earth orbit (VLEO) satellites face extremely complex thermal conditions during operation. Unlike conventional orbit satellites, VLEO satellites gradually decrease in orbital altitude, resulting in drastic changes in atmospheric density and a significant enhancement of aerodynamic thermal effects. Simultaneously, during flight, the satellite needs to switch between conventional and vertical flight attitudes multiple times according to mission requirements. These attitude changes directly affect the absorption of solar radiation by the satellite's surface and the reception of Earth's albedo.

[0004] Traditional satellite thermal simulation methods typically calculate orbit, attitude, thermal control, and payload systems separately, or use simplified steady-state thermal analysis models, which make it difficult to accurately reflect the transient thermal effects caused by the strong coupling of multiple physics fields in the ultra-low orbit environment.

[0005] Existing technologies suffer from the following main drawbacks: First, they lack a dynamic coupling mechanism across the entire process. When processing ultra-low Earth orbit (EEO) satellites, existing methods typically neglect the real-time interaction between the atmospheric model and the orbital and attitude systems, leading to significant errors in the calculation of thermal boundary conditions. Second, the thermal simulation modules are severely decoupled. Key thermal effect modules such as aerodynamic heating, solar-Earth heat flux, and heat pipe two-phase flow are usually calculated independently, making it impossible to achieve data linkage between multiple modules and hindering the rapid output of relevant thermal calculation results. Third, it is difficult to balance computational efficiency and accuracy. In pursuit of high accuracy, existing methods often consume substantial computational resources and cannot achieve dynamic thermal monitoring, making it difficult to meet the real-time requirements of complex mission conditions.

[0006] Therefore, there is an urgent need for a full-process coupled thermal simulation system for ultra-low orbit satellites that can interact and link with various systems such as attitude, orbit, and payload missions for complex mission conditions in ultra-low orbit, and couple multiple modules such as atmospheric model, solar-Earth heat flow calculation, aerodynamics, aerothermal calculation, and heat pipe two-phase flow, so as to improve computational efficiency and realize full-process dynamic thermal monitoring of complex ultra-low orbit missions. Summary of the Invention

[0007] The objective of this invention is to provide a coupled thermal simulation method and system for the entire process of ultra-low orbit (ULE) satellites. This method and / or system addresses the problems of low computational efficiency and difficulty in achieving dynamic thermal monitoring throughout the entire process of complex ULE missions in existing technologies. The method and / or system couples multiple core modules, including an aerodynamic and aerothermal calculation module, a space thermal environment calculation module, and a loop heat pipe two-phase flow calculation module. This enables rapid output of thermal calculation results according to the timing requirements of the entire satellite mission process, thus achieving dynamic thermal monitoring throughout the entire process of complex ULE missions.

[0008] In a first aspect of the invention, the aforementioned task is solved by a fully coupled thermal simulation method for ultra-low orbit satellites, the method comprising the following steps:

[0009] A fully coupled thermal simulation system is constructed, comprising a human-computer interaction interface and an internal calculation program; the human-computer interaction interface includes an input setting interface and an output display interface; the internal calculation program includes a control layer, a calculation layer, and a data layer.

[0010] In the control layer, the satellite's geometric mesh file and orbital attitude parameter file are imported through the input settings interface, and the simulation time and mission flow sequence are set.

[0011] The control layer passes the imported parameters to the calculation layer and starts time-iterative calculation;

[0012] In the computation layer, the following three computation modules are coupled and executed:

[0013] Aerodynamic and aerothermal calculation module: Based on Knudsen number, determine the flow region where the satellite is located and calculate the aerodynamic heat flux on the satellite surface;

[0014] Space thermal environment calculation module: Calculates solar radiation heat flux, Earth albedo heat flux, and Earth infrared heat flux based on satellite orbital position, attitude pointing towards the sun, and Earth parameters; and

[0015] Loop heat pipe two-phase flow calculation module: Using a partitioned calculation method, the superheated gas phase region, two-phase region and subcooled liquid phase region of the working fluid in the loop heat pipe are calculated unit by unit to obtain the heat pipe operating status and temperature distribution;

[0016] The computation layer transmits the calculation results from the three computation modules to the data layer for integration, forming a data file containing real-time temperature field, heat flux distribution, aerodynamic parameters, and heat pipe status; and

[0017] The data layer transmits the integrated data file to the output display interface, which displays the simulation results in real time in the form of numerical values, curves, or cloud maps, and shows the changing trend of parameters throughout the entire orbital mission cycle.

[0018] In one embodiment of the present invention, the ultra-low orbit satellite full-process coupled thermal simulation method further includes: in the computing layer, according to the timing of the satellite mission process, dynamically calling different computing modules to realize real-time interaction and linkage with the attitude, orbit, and payload mission subsystems.

[0019] In one embodiment of the present invention, the Knudsen number is calculated in the aerodynamic and aerothermal calculation module using the following formula. ,

[0020]

[0021]

[0022] in, Represents the Mach number. Indicates the incoming Reynolds number, Indicates the incoming flow density. Indicates the incoming flow velocity. Indicates the characteristic length. Indicates the viscosity coefficient of the incoming gas;

[0023] The method for determining the flow region of a satellite based on Knudsen numbers is as follows: when When ≤0.05, the satellite is in a continuous flow region; when 0.05 < When <3.0, the satellite is in the transition flow region; when At ≥3.0, the satellite is in the free molecular flow region.

[0024] In one embodiment of the present invention, the loop heat pipe two-phase flow calculation module uses a unit-by-unit iteration method to determine the working fluid phase state by comparing the current unit outlet temperature with the saturation temperature under the corresponding pressure, and calls the gas phase module, two-phase module or liquid phase module respectively for calculation.

[0025] In one embodiment of the present invention, the output display interface supports multi-form visualization of real-time calculated data, time history curves, temperature fields, and heat flux density cloud maps.

[0026] In one embodiment of the present invention, the full-process coupled thermal simulation method for ultra-low orbit satellites further includes: iteratively optimizing the design of the satellite thermal management system based on the simulation calculation results.

[0027] In a second aspect of the invention, the aforementioned task is also addressed by a fully coupled thermal simulation system for ultra-low Earth orbit satellites, the system comprising:

[0028] The input settings interface is configured to receive user input of satellite geometric mesh files, orbital attitude parameter files, simulation time, and mission flow timing.

[0029] The control layer is configured to parse the parameters input from the input settings interface and control the simulation process.

[0030] The computation layer further includes:

[0031] The aerodynamic and aerothermal calculation module is configured to determine the flow region of the satellite based on the Knudsen number and calculate the aerodynamic heat flux on the satellite surface.

[0032] The space thermal environment calculation module is configured to calculate solar radiation heat flux, Earth albedo heat flux, and Earth infrared heat flux based on satellite orbital position, attitude pointing, solar position, and Earth parameters.

[0033] The loop heat pipe two-phase flow calculation module is configured to use a partitioned calculation method to perform unit-by-unit calculations on the superheated gas phase region, two-phase region and subcooled liquid phase region of the working fluid in the loop heat pipe, so as to obtain the heat pipe operating status and temperature distribution.

[0034] The data layer is configured to integrate the calculation results of the computing modules to form a data file;

[0035] The output display interface is configured to display simulation results in real time in the form of numerical values, curves, or contour plots, and to show the trend of parameter changes throughout the entire orbital mission cycle.

[0036] In one embodiment of the present invention, the ultra-low orbit satellite full-process coupled thermal simulation system further includes an optimization module, which is configured to iteratively optimize the design of the satellite thermal management system based on the simulation calculation results.

[0037] In a third aspect, the present invention also provides an electronic device comprising:

[0038] A processor, configured to execute machine-readable instructions;

[0039] The graphics card is configured to train the described full-process coupled thermal simulation method for ultra-low orbit satellites; and

[0040] A memory configured to store machine-readable instructions that, when executed by a processor and / or graphics card, perform the steps of the described ultra-low orbit satellite full-process coupled thermal simulation method.

[0041] In a fourth aspect, the present invention also provides a computer-readable storage medium having stored thereon computer-readable instructions, which, when executed by a processor, perform the steps of the ultra-low orbit satellite full-process coupled thermal simulation method.

[0042] The technical solution provided by this invention has the following advantages:

[0043] 1) The full-process coupled thermal simulation method and / or system for ultra-low orbit satellites proposed in this invention solves the problem of fragmented operating conditions caused by traditional segmented simulation by coupling multiple modules such as aerodynamic and aerothermal calculation module, space thermal environment calculation module and loop heat pipe two-phase flow calculation module, realizes real-time interaction of multi-physics field data, and significantly improves the accuracy of thermal analysis under complex ultra-low orbit missions.

[0044] 2) The proposed method and / or system for full-process coupled thermal simulation of ultra-low orbit satellites, through modular encapsulation and parallel computing architecture, rapidly outputs relevant thermal calculation results via optimized computational logic, improving computational efficiency and shortening the design cycle. This invention reduces the time required for a single thermal environment analysis from minutes to seconds (within 10 seconds) using traditional methods, meeting the simulation speed requirements of complex dynamic tasks and significantly improving design iteration efficiency.

[0045] 3) During flight, the orbital altitude gradually decreases, and the conventional attitude and vertical flight attitude are switched multiple times as required by the mission. The ultra-low orbit satellite full-process coupled thermal simulation method and / or system proposed in this invention can track these changes in real time. The temperature changes of each major measuring point in the system can be accurately captured. Through the display of the full-process analysis results, the thermal management effect of the system can be evaluated intuitively and comprehensively.

[0046] 4) The ultra-low orbit satellite full-process coupled thermal simulation method and / or system proposed in this invention constructs an integrated thermal simulation system that integrates multiple core computing modules and achieves linkage with various satellite subsystems. It also supports various forms of visualization output such as numerical values, curves, and cloud maps, which makes it convenient for designers to intuitively and comprehensively evaluate the satellite thermal management effect and improve design efficiency and decision-making quality. Attached Figure Description

[0047] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the various embodiments of the present invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.

[0048] Figure 1 A schematic diagram comparing the full-process thermal conditions with traditional typical thermal conditions is shown;

[0049] Figure 2 A flowchart illustrating a full-process coupled thermal simulation method for ultra-low orbit satellites according to an embodiment of the present invention is shown.

[0050] Figure 3 A schematic diagram of a full-process coupled simulation calculation framework according to an embodiment of the present invention is shown;

[0051] Figure 4 This diagram illustrates an embodiment of the present invention for determining the flow region of a satellite based on the Knudsen number.

[0052] Figure 5 A flowchart illustrating a two-phase flow computational modeling method for loop heat pipes according to an embodiment of the present invention is shown.

[0053] Figure 6 This diagram illustrates the main simulation content of a full-process coupled thermal simulation method for ultra-low orbit satellites according to an embodiment of the present invention.

[0054] Figure 7 A schematic diagram of a fully coupled thermal simulation system for ultra-low orbit satellites according to an embodiment of the present invention is shown; and

[0055] Figure 8 A schematic diagram of the full-process simulation temperature curve of the annular heat sink according to an embodiment of the present invention is shown. Detailed Implementation

[0056] In the following description, the invention is described with reference to various embodiments. However, those skilled in the art will recognize that the embodiments may be practiced without one or more specific details or with other alternatives and / or additional methods or components. In other instances, well-known structures or operations are not shown or described in detail so as not to obscure the inventive points of the invention. Similarly, for illustrative purposes, specific numbers and configurations are set forth to provide a comprehensive understanding of the embodiments of the invention. However, the invention is not limited to these specific details.

[0057] In this specification, references to "an embodiment" or "this embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. The phrase "in one embodiment" appearing throughout this specification does not necessarily refer to the same embodiment in all instances.

[0058] It should be noted that the embodiments of the present invention describe the method steps in a specific order; however, this is only for illustrating the specific embodiment and not for limiting the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to actual needs.

[0059] In this invention, the various networks, modules, or units of the system according to the invention can be implemented using software, hardware, firmware, or a combination thereof. When a module is implemented using software, its function can be implemented through computer program flow. For example, the module can be implemented using code segments (such as code segments in languages ​​like C and C++) stored in a storage device (such as a hard disk, memory, etc.), wherein the corresponding function of the module can be implemented when the code segment is executed by a processor. When a module is implemented using hardware, its function can be implemented by setting a corresponding hardware structure. For example, the module's function can be implemented by hardware programming a programmable device such as a field-programmable gate array (FPGA), or by designing an application-specific integrated circuit (ASIC) that includes multiple transistors, resistors, capacitors, and other electronic devices. When a module is implemented using firmware, the module's function can be written in the form of program code into a read-only memory such as an EPROM or EEPROM of the device, and the corresponding function of the module can be implemented when the program code is executed by a processor. In addition, some functions of the module may need to be implemented by separate hardware or by working in cooperation with the hardware. For example, the detection function is implemented by a corresponding sensor (such as a proximity sensor, accelerometer, gyroscope, etc.), the signal transmission function is implemented by a corresponding communication device (such as a Bluetooth device, infrared communication device, baseband communication device, Wi-Fi communication device, etc.), the output function is implemented by a corresponding output device (such as a display, speaker, etc.), and so on.

[0060] Figure 1 A schematic diagram comparing the full-process thermal conditions with traditional typical thermal conditions is shown. For example... Figure 1 As shown, the thermal control system of ultra-low orbit (ULE) satellites needs to closely consider changes in mission flow and external thermal environment. Key influencing factors include internal heat dissipation, external heat flux, attitude pointing, and orbital changes. Traditional thermal condition selection involves combining and superimposing extreme cases of various influencing factors to form typical conditions of extreme high or low temperatures. This invention considers all influencing factors simultaneously over time, covering the entire mission flow to form a complete ULE thermal condition. It further completes simulation calculations of the ULE thermal protection and heat dissipation system and iteratively optimizes the design of the thermal management system based on the calculation results.

[0061] Ultra-Low Orbit (UO) full-process simulation refers to the simulation following the UO mission flow, where parameters such as attitude and orbit change rapidly, and internal load cells activate and operate according to the mission sequence, leading to rapid changes in the external and internal thermal environments. The UO full-process thermal simulation system can quickly output relevant thermal calculation results, unlike traditional simulations which only select extreme conditions. The full-process thermal simulation system focuses on improving computational efficiency and increasing the interoperability between systems, thereby achieving dynamic monitoring of the entire complex mission process.

[0062] This invention provides a full-process coupled thermal simulation method for ultra-low orbit (ULE) satellites. Due to the complexity and unique scenarios of ULE missions, it is necessary to consider not only the solar and terrestrial heat flux of traditional satellites but also the aerodynamic heating heat flux of ULE satellites. Furthermore, it is essential to calculate the two-phase flow heat transfer of the loop heat pipes within the system. These three computational modules constitute the core of the thermal simulation system. The constructed thermal simulation system needs to be able to couple orbital and attitude changes. Through a defined interface, it receives real-time orbital and attitude data, enabling full-process ULE simulation calculations according to the background mission flow. This invention provides a full-process coupled thermal simulation method for ULE satellites that can visualize the simulation results, enabling real-time monitoring of the satellite's current force and thermal environment status, displayed in numerical, curve, or cloud map formats. It can also show the changing trends of multiple key parameters throughout the entire orbital mission cycle. By integrating coupled thermal flux simulation into the full-process platform, it achieves integration with attitude, orbit, and telemetry and control subsystems, enabling real-time, online simulation calculations of aerodynamic heat and extra-satellite heat flux during the satellite's orbital mission cycle.

[0063] Figure 2 A flowchart illustrating a full-process coupled thermal simulation method for ultra-low orbit satellites according to an embodiment of the present invention is shown. Figure 3 A schematic diagram of a full-process coupled simulation calculation framework according to an embodiment of the present invention is shown below. Figure 2 and Figure 3 This describes the process of the full-process coupled thermal simulation method for ultra-low orbit satellites provided by this invention. For example... Figure 2 As shown, the method includes the following steps:

[0064] Step 201: Construct a full-process coupled thermal simulation system, which includes a human-computer interface and an internal calculation program. In one embodiment of the present invention, the human-computer interface can be developed using C++ and Qt frameworks, supporting graphical input and output operations; the internal calculation program adopts a modular architecture.

[0065] Figure 7 A schematic diagram of a fully coupled thermal simulation system for ultra-low Earth orbit satellites according to an embodiment of the present invention is shown. Figure 7 As shown, the human-computer interaction interface includes an input setting interface 701 and an output display interface 705. The internal calculation program 706 includes a control layer 702, a calculation layer 703, and a data layer 704. The input setting interface 701 is the presentation layer 7011, and the output display interface 705 is the image layer 7051.

[0066] Step 202: In the control layer, import the satellite's geometric mesh file and orbital attitude parameter file through the input settings interface, and set the simulation time and mission sequence. For example... Figure 7As shown, the control layer 702 is responsible for parsing the simulation parameters input by the user, including the satellite geometric mesh file (.msh format), the orbital attitude parameter file (.txt format), the simulation start and end times, control parameters (Input.inp), the mission timing table, etc.

[0067] Step 203: The control layer passes the imported parameters to the calculation layer and starts the time iteration calculation.

[0068] Step 204: In the computational layer, couple and execute the aerodynamic and aerothermal calculation module, the space thermal environment calculation module, and the loop heat pipe two-phase flow calculation module. For example... Figure 7 As shown, aerodynamics, aerothermal energy, external atmospheric heat, and internal heat transfer calculations are performed in computational layer 703. The computational layer includes an aerodynamics and aerothermal energy calculation module, a space thermal environment calculation module, and a loop heat pipe two-phase flow calculation module.

[0069] The aerodynamic and aerothermal calculation module primarily uses the Knudsen number to determine the flow region in which the satellite is located and calculates the aerodynamic heat flux on the satellite surface. When a satellite re-enters the atmosphere at supersonic speeds, its orbital position passes through different fluid regions, including free molecular flows at high altitudes, transitional flows at mid-altitudes, and continuous flows at low altitudes. The aerodynamic and thermal environments encountered in each of these different flow regions vary, and the corresponding calculation methods also change. Therefore, when calculating the aerodynamic and thermal environment of a very low Earth orbit satellite, the first step is to use the Knudsen number... The satellite's location is determined, and then the aerodynamic and thermal environment is calculated using a suitable formula.

[0070] The Knudsen number is the ratio of the mean free path of the molecules to the characteristic size of the objects in the flow field, and it has the following relationship with the flow field parameters:

[0071]

[0072]

[0073] in, Represents the Mach number. Indicates the incoming Reynolds number, Indicates the incoming flow density. Indicates the incoming flow velocity. Indicates the characteristic length. This represents the viscosity coefficient of the incoming gas.

[0074] Figure 4 This diagram illustrates an embodiment of the present invention for determining the flow region of a satellite based on the Knudsen number. As altitude increases, atmospheric density gradually decreases, and the calculated Knudsen number changes accordingly. The method for determining the flow region of a satellite based on the Knudsen number is as follows: when... When ≤0.05, the satellite is in a continuous flow region; when 0.05 < When <3.0, the satellite is in the transition flow region; when At ≥3.0, the satellite is in the free molecular flow region.

[0075] The space thermal environment calculation module mainly calculates solar radiation heat flow, Earth albedo heat flow, and Earth infrared heat flow based on the satellite's orbital position, attitude pointing towards the sun, and Earth parameters.

[0076] Loop heat pipe two-phase flow calculation module: Using a partitioned calculation method, the superheated gas phase region, two-phase region and subcooled liquid phase region of the working fluid in the loop heat pipe are calculated unit by unit to obtain the heat pipe operating status and temperature distribution.

[0077] In one embodiment of the present invention, in the loop heat pipe two-phase flow calculation module, a unit-by-unit iteration method is used to determine the working fluid phase state by comparing the current unit outlet temperature with the saturation temperature under the corresponding pressure, and to call the gas phase module, two-phase module or liquid phase module respectively for calculation.

[0078] In this embodiment, the satellite uses a loop heat pipe as the main heat transfer device. The working fluid (such as ammonia) inside the loop heat pipe absorbs heat and evaporates in the evaporator, enters the gas phase region, releases heat and condenses in the condenser, and then returns to the evaporator through the liquid pipeline.

[0079] This module employs a one-dimensional partitioning calculation method, dividing the loop heat pipe into several control units along the flow direction. Each unit is calculated sequentially, assigning the outlet parameters of the previous unit to the inlet of the next unit, and determining whether the outlet temperature of each unit has reached the saturation temperature at that outlet pressure. Figure 5 A schematic flowchart of a two-phase flow computational modeling method for a loop heat pipe according to an embodiment of the present invention is shown. Figure 5 As shown, the calculation process is as follows:

[0080] The initial working fluid is set to superheated gas, which enters the gas phase module;

[0081] For each unit, calculate the unit's outlet temperature, pressure, and dryness based on the inlet parameters;

[0082] Determine whether the outlet temperature of the unit has reached the saturation temperature at the current outlet pressure:

[0083] If the outlet temperature of the unit is greater than the saturation temperature, it is still considered superheated gas, and the gas phase module will continue to be used for the calculation of the next gas phase unit.

[0084] If the outlet temperature of the unit reaches the saturation temperature of that state, it indicates that the internal working fluid has begun to enter the two-phase region and a phase change has begun. The next unit will then use the two-phase region module for calculation.

[0085] In the two-phase region module, calculate the outlet dryness of the unit:

[0086] As flow and heat exchange continue, the dryness fraction changes in the two-phase region. Here, dryness fraction is used to determine whether the calculation has entered the liquid phase region. If the dryness fraction at the outlet of the calculation unit is greater than 0, it indicates the presence of gaseous working fluid, meaning it remains in the two-phase region, and the calculation continues.

[0087] If the outlet dryness reaches 0, the working fluid will completely condense and enter the subcooled liquid phase region, and subsequent units will switch to the liquid phase module.

[0088] Using the above method, this module can accurately simulate the two-phase flow and heat transfer characteristics of a loop heat pipe under dynamic thermal boundary conditions, and output key parameters such as temperature distribution, working fluid flow rate, and phase change location of each section of the heat pipe.

[0089] Step 205: The computational layer transfers the calculation results from the three computational modules to the data layer for integration, forming a data file containing real-time temperature field, heat flux distribution, aerodynamic parameters, and heat pipe status. For example... Figure 7 As shown, various data files are formed in data layer 704.

[0090] Step 206: The data layer transfers the integrated data file to the output display interface, displaying the simulation results in real time in the form of numerical values, curves, or contour plots, and showing the parameter variation trends throughout the entire orbital mission cycle. For example... Figure 7 As shown, the output display interface 705 displays the results of real-time calculations, curves changing over time, and cloud maps. In one embodiment of the present invention, the output display interface supports multi-form visualization of real-time calculation data, time history curves, and temperature fields and heat flux density cloud maps.

[0091] In one embodiment of the present invention, the full-process coupled thermal simulation method for ultra-low orbit satellites further includes: in the computing layer, dynamically calling different computing modules according to the timing of the satellite mission process to achieve real-time interaction and linkage with the attitude, orbit, and payload mission subsystems.

[0092] In one embodiment of the present invention, the full-process coupled thermal simulation method for ultra-low orbit satellites further includes: iteratively optimizing the design of the satellite thermal management system based on the simulation calculation results.

[0093] Figure 6 This diagram illustrates the main simulation content of a full-process coupled thermal simulation method for ultra-low orbit satellites according to an embodiment of the present invention. (See diagram for example.) Figure 6As shown, aerodynamic and thermal environment simulations are performed by inputting real-time changing attitude and flight conditions. Aerodynamic simulation involves calculations from the aerodynamic and aerothermal calculation modules. Thermal environment simulation includes calculations from the space thermal environment calculation module and the loop heat pipe two-phase flow calculation module. The outputs of aerodynamic simulation include aerodynamic forces, aerodynamic torque, aerodynamic coefficients, and pressure center position. The outputs of thermal environment simulation include conventional external heat flow, aerodynamic thermal environment, and loop heat pipe operating status. All major inputs and outputs are visualized using dynamic numbers, curves, and contour maps.

[0094] Figure 7 A schematic diagram of a fully coupled thermal simulation system for ultra-low Earth orbit (ULE) satellites according to an embodiment of the present invention is shown. This fully coupled thermal simulation system for ULE satellites can be applied to the aforementioned fully coupled thermal simulation method for ULE satellites. Figure 7 As shown, the system includes:

[0095] Input settings interface 701 is used to receive user input of satellite geometric mesh files, orbital attitude parameter files, simulation time, and mission flow sequence.

[0096] The control layer 702 is used to parse the parameters input from the input settings interface and control the simulation process.

[0097] The computational layer 703 performs calculations for aerodynamics, aerothermal processes, external atmospheric heat, and internal heat transfer. The computational layer includes modules for aerodynamics and aerothermal calculations, a space thermal environment calculation module, and a loop heat pipe two-phase flow calculation module.

[0098] The aerodynamic and aerothermal calculation module determines the flow region of the satellite based on the Knudsen number and is used for aerodynamic and aerothermal calculations on the satellite surface.

[0099] The space thermal environment calculation module calculates atmospheric external heat (e.g., solar radiation heat flow, Earth albedo heat flow, and Earth infrared heat flow) based on satellite orbital position, attitude orientation, solar position, and Earth parameters.

[0100] The loop heat pipe two-phase flow calculation module is used to calculate internal heat transfer. It uses a zone calculation method to perform unit-by-unit calculations on the superheated gas phase region, two-phase region and subcooled liquid phase region of the working fluid in the loop heat pipe to obtain the heat pipe operating status and temperature distribution.

[0101] Data layer 704 integrates the calculation results of computation layer 703 to form a data file.

[0102] The output display interface 705 displays the simulation results in real time in the form of numerical values, curves, or contour maps, and shows the changing trend of parameters throughout the entire orbital mission cycle.

[0103] The specific operation flow of the ultra-low orbit satellite full-process coupled thermal simulation system provided by this invention is as follows: Start SimulationPlatform.exe; set the software working path; the user imports the .msh format mesh file and the .txt format orbital attitude information; set the calculation parameters in the interactive interface; call Hypersonic.exe to perform the simulation calculation; after the calculation is completed, the software automatically loads the .temp and .dat calculation result files and forms a monitoring screen according to the user's requirements.

[0104] In one embodiment of the present invention, the ultra-low orbit satellite full-process coupled thermal simulation system further includes an optimization module, which is configured to iteratively optimize the design of the satellite thermal management system based on the simulation calculation results.

[0105] The proposed full-process coupled thermal simulation method for ultra-low orbit satellites can be used for full-process calculation simulation of ultra-low orbit satellites, and the calculation results cover the entire flight mission. Figure 8 This diagram illustrates the temperature curve of a ring-shaped heat sink in a low-orbit full-process simulation according to an embodiment of the present invention. During flight, the orbital altitude gradually decreases, and the system switches between conventional and vertical flight attitudes multiple times as required by the mission. The temperature at various key measuring points in the system changes with orbital altitude, attitude variations, and load-induced heat generation. By displaying the full-process analysis results, the thermal management effectiveness of the system can be intuitively and comprehensively evaluated. Figure 8 As shown, the temperature fluctuates periodically as the orbital altitude gradually decreases, the attitude mode changes, and the payload operates, which can truly reflect the dynamic changes in the satellite's on-orbit thermal environment.

[0106] The proposed method and / or system for full-process coupled thermal simulation of ultra-low orbit satellites in this invention constructs an integrated thermal simulation system that integrates multiple core computing modules and links with various subsystems of the satellite. It also supports various forms of visualization output, such as numerical values, curves, and cloud maps, which facilitates designers to intuitively and comprehensively evaluate the effectiveness of satellite thermal management and improve design efficiency and decision-making quality.

[0107] In one embodiment of the present invention, the present invention also provides an electronic device, the device including a processor, a graphics card, and a memory, the memory being configured to store machine-readable instructions, the graphics card being configured to train the full-process coupled thermal simulation method for ultra-low orbit satellites, and the processor being configured to execute machine-readable instructions. When the processor and / or graphics card execute machine-readable instructions, the following processing steps are implemented: A fully coupled thermal simulation system is constructed, comprising a human-computer interface and an internal calculation program. The human-computer interface includes an input setting interface and an output display interface. The internal calculation program includes a control layer, a calculation layer, and a data layer. In the control layer, the satellite's geometric mesh file and orbital attitude parameter file are imported through the input setting interface, and the simulation time and mission flow sequence are set. The control layer transmits the imported parameters to the calculation layer and initiates time-iterative calculations. In the calculation layer, the aerodynamic and aerothermal calculation modules, the space thermal environment calculation module, and the loop heat pipe two-phase flow calculation module are coupled and executed. The calculation layer transmits the calculation results of the above three calculation modules to the data layer for integration, forming a data file of real-time temperature field, heat flow distribution, aerodynamic parameters, and heat pipe status. The data layer transmits the integrated data file to the output display interface, displaying the simulation results in real-time in the form of numerical values, curves, or cloud maps, and showing the parameter change trends throughout the entire orbital mission cycle.

[0108] The graphics card used can preferably be a model with a GPU computing power higher than 5.0. Since the amount of data to be trained is large, providing a graphics card configuration can significantly improve the training speed.

[0109] The memory includes various media capable of storing machine-readable instructions, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0110] It is understood that, in addition to the memory and processor mentioned above, the computer system described above also includes other hardware and software components not listed in this specification. The specific components can be determined according to the model of the specific data processing equipment in different application scenarios, and will not be listed and described in detail in this specification.

[0111] In one embodiment of the present invention, a computer-readable storage medium is also provided, on which machine-readable instructions are stored. When executed by a processor, the machine-readable instructions perform the following processing steps: constructing a full-process coupled thermal simulation system, the thermal simulation system including a human-computer interaction interface and an internal calculation program, the human-computer interaction interface including an input setting interface and an output display interface, the internal calculation program including a control layer, a calculation layer, and a data layer; in the control layer, importing the satellite's geometric mesh file and orbital attitude parameter file through the input setting interface, and setting the simulation time and mission flow sequence; the control layer transmits the imported parameters to the calculation layer and starts time iteration calculation; in the calculation layer, coupling and executing the aerodynamic and aerothermal calculation module, the space thermal environment calculation module, and the loop heat pipe two-phase flow calculation module; the calculation layer transmits the calculation results of the above three calculation modules to the data layer for integration, forming a data file of real-time temperature field, heat flow distribution, aerodynamic parameters, and heat pipe status; the data layer transmits the integrated data file to the output display interface, displaying the simulation results in real-time in the form of numerical values, curves, or cloud maps, and showing the parameter change trend throughout the entire orbital mission cycle.

[0112] Although various embodiments of the present invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined according to the technical solutions of the invention and their equivalents.

Claims

1. A fully coupled thermal simulation method for ultra-low orbit satellites, characterized in that, Includes the following steps: A fully coupled thermal simulation system is constructed, comprising a human-computer interaction interface and an internal calculation program; the human-computer interaction interface includes an input setting interface and an output display interface; the internal calculation program includes a control layer, a calculation layer, and a data layer. In the control layer, the satellite's geometric mesh file and orbital attitude parameter file are imported through the input settings interface, and the simulation time and mission flow sequence are set. The control layer passes the imported parameters to the calculation layer and starts time-iterative calculation; In the computation layer, the following three computation modules are coupled and executed: Aerodynamic and aerothermal calculation module: Based on Knudsen number, determine the flow region where the satellite is located and calculate the aerodynamic heat flux on the satellite surface; Space thermal environment calculation module: Calculates solar radiation heat flux, Earth albedo heat flux, and Earth infrared heat flux based on satellite orbital position, attitude pointing towards the sun, and Earth parameters; as well as Loop heat pipe two-phase flow calculation module: Using a partitioned calculation method, the superheated gas phase region, two-phase region and subcooled liquid phase region of the working fluid in the loop heat pipe are calculated unit by unit to obtain the heat pipe operating status and temperature distribution; The calculation layer transmits the calculation results of the above three calculation modules to the data layer for integration, forming a data file of real-time temperature field, heat flow distribution, aerodynamic parameters and heat pipe status; as well as The data layer transmits the integrated data file to the output display interface, which displays the simulation results in real time in the form of numerical values, curves, or cloud maps, and shows the changing trend of parameters throughout the entire orbital mission cycle.

2. The ultra-low orbit satellite full-process coupled thermal simulation method according to claim 1, characterized in that, Also includes: In the computing layer, different computing modules are dynamically invoked according to the timing of the satellite mission process, enabling real-time interaction and linkage with the attitude, orbit, and payload mission subsystems.

3. The ultra-low orbit satellite full-process coupled thermal simulation method according to claim 1, characterized in that, In the aerodynamic and aerothermal calculation module, the Knudsen number is calculated using the following formula. , in, Represents the Mach number. Indicates the incoming Reynolds number, Indicates the incoming flow density. Indicates the incoming flow velocity. Indicates the characteristic length. Indicates the viscosity coefficient of the incoming gas; The method for determining the flow region of a satellite based on Knudsen numbers is as follows: when When ≤0.05, the satellite is in a continuous flow region; when 0.05 < When <3.0, the satellite is in the transition flow region; when At ≥3.0, the satellite is in the free molecular flow region.

4. The ultra-low orbit satellite full-process coupled thermal simulation method according to claim 1, characterized in that, In the loop heat pipe two-phase flow calculation module, a unit-by-unit iterative method is used to determine the working fluid phase state by comparing the current unit outlet temperature with the saturation temperature under the corresponding pressure, and then calling the gas phase module, two-phase module or liquid phase module for calculation respectively.

5. The ultra-low orbit satellite full-process coupled thermal simulation method according to claim 1, characterized in that, The output display interface supports multiple forms of visualization, including real-time calculated data, time history curves, temperature fields, and heat flux density cloud maps.

6. The ultra-low orbit satellite full-process coupled thermal simulation method according to claim 1, characterized in that, Also includes: Based on the simulation results, the design of the satellite thermal management system was iteratively optimized.

7. A fully coupled thermal simulation system for ultra-low Earth orbit satellites, characterized in that, include: The input settings interface is configured to receive user input of satellite geometric mesh files, orbital attitude parameter files, simulation time, and mission flow timing. The control layer is configured to parse the parameters input from the input settings interface and control the simulation process. The computation layer further includes: The aerodynamic and aerothermal calculation module is configured to determine the flow region of the satellite based on the Knudsen number and calculate the aerodynamic heat flux on the satellite surface. The space thermal environment calculation module is configured to calculate solar radiation heat flux, Earth albedo heat flux, and Earth infrared heat flux based on satellite orbital position, attitude pointing, solar position, and Earth parameters. The loop heat pipe two-phase flow calculation module is configured to use a partitioned calculation method to perform unit-by-unit calculations on the superheated gas phase region, two-phase region and subcooled liquid phase region of the working fluid in the loop heat pipe, so as to obtain the heat pipe operating status and temperature distribution. A data layer, configured to integrate the calculation results of the computing modules to form a data file; and The output display interface is configured to display simulation results in real time in the form of numerical values, curves, or contour plots, and to show the trend of parameter changes throughout the entire orbital mission cycle.

8. The ultra-low orbit satellite full-process coupled thermal simulation system according to claim 7, characterized in that, It also includes an optimization module, which is configured to iteratively optimize the design of the satellite thermal management system based on simulation calculation results.

9. An electronic device, characterized in that, include: A processor, configured to execute machine-readable instructions; A graphics card configured to train the full-process coupled thermal simulation method for ultra-low orbit satellites as described in any one of claims 1-6; and A memory configured to store machine-readable instructions that, when executed by a processor and / or graphics card, perform the steps of the full-process coupled thermal simulation method for ultra-low orbit satellites according to any one of claims 1-6.

10. A computer-readable storage medium storing computer-readable instructions thereon, characterized in that, When the computer-readable instructions are executed by the processor, they perform the steps of the full-process coupled thermal simulation method for ultra-low orbit satellites as described in any one of claims 1-6.

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