A thermal working condition timing matching method based on typical mission profiles of high-speed aircrafts

Abstract

The application belongs to the field of aircraft design, and particularly relates to a thermal force working condition time sequence matching method based on a typical task profile of a high-speed aircraft, which determines a heat exchange surface of thermal conduction simulation calculation, matches parameters in combination with a flight profile of the high-speed aircraft, and obtains heat flow input at each time point in a simulation process; a thermal conduction simulation model of the high-speed aircraft is constructed based on the heat flow input; according to a flight working condition of an aerodynamic load to be analyzed, aerodynamic force loads are obtained for interpolation and load balancing, node force loads of each working condition for loading are formed, and are input into the thermal conduction simulation model; a finite element simulation input file is analyzed, a finite element simulation input file format is referred to, a calculation file for commercial finite element software calculation simulation is converted, and efficient batch thermal force coupling calculation simulation is performed. Reliable, efficient and normative solving of thermal force coupling strength simulation of the high-speed aircraft with a clear task profile is realized.

Description

Technical Field

[0001] This application belongs to the field of aircraft design, and specifically relates to a thermodynamic condition timing matching method based on a typical mission profile of a high-speed aircraft. Background Technology

[0002] High-speed aircraft are a new type of reusable aircraft capable of wide-speed-range flight and supersonic cruise. During high-speed flight, these aircraft experience severe aerodynamic heating, causing a rapid increase in surface temperature. Unlike traditional aircraft, the effects of high temperatures cannot be ignored in the structural layout optimization and weight design of high-speed aircraft. Furthermore, thermal loads differ from mechanical loads, requiring full-section transient calculations to obtain the thermal loads throughout the entire cross-sectional process. Therefore, the mechanical-thermal coupled loads represent a massive number of load conditions throughout the entire cross-sectional process. Using traditional simulation design methods to calculate and optimize these massive load conditions would consume significant human and computational resources, severely impacting the design and development speed.

[0003] To address the aforementioned issues, it is urgently necessary to fully utilize the flight state characteristics of thermal load data to achieve time-series matching processing of thermal coupling conditions. Establishing methods for batch generation and calculation of thermal coupling simulation files will improve the efficiency of aircraft simulation design and effectively support aircraft weight reduction. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft, thereby resolving the problem of low efficiency in calculating and optimizing massive load conditions using traditional simulation design methods in the prior art.

[0005] The technical solution of this application is: a thermodynamic condition timing matching method based on a typical mission profile of a high-speed aircraft, including:

[0006] The heat exchange surface for heat conduction simulation calculation is determined, and parameters are matched in conjunction with the flight profile of a high-speed aircraft to obtain the heat flow input at each time point during the simulation; a heat conduction simulation model of a high-speed aircraft is constructed based on the heat flow input.

[0007] Based on the flight conditions of the aerodynamic loads to be analyzed, the aerodynamic loads are obtained, interpolated, and load balanced to form the nodal force loads for loading under each condition, which are then input into the heat conduction simulation model.

[0008] The finite element simulation input file is parsed and converted into a calculation file for use in commercial finite element software, in accordance with the finite element simulation input file format, to perform high-efficiency batch thermal coupling calculation simulation.

[0009] Preferably, a heat conduction simulation model for a high-speed aircraft is constructed based on the heat flow input, specifically as follows:

[0010] Based on the heat exchange surface, establish the heat flow input matching relationship between the heat exchange surface and the finite element model and the aerothermal input file, organize the aerothermal input flight state data, and determine the reference aerothermal reference flight state;

[0011] The high-speed aircraft flight profile is matched with the aerodynamic thermal reference flight state, and the heat flow input at each time point during the simulation is obtained by linear interpolation. The linear interpolation is performed on the flight profile at intervals of no more than 1 / 400 of the total flight time, and different flight states at the same Mach number and altitude are calculated separately.

[0012] A heat conduction simulation model of a high-speed aircraft was constructed. The heat conduction model was loaded and calculated based on transient heat flow input. The simulation results of the transient temperature field of the whole aircraft were obtained, which provided thermal load input for subsequent thermo-mechanical coupling matching simulation calculation.

[0013] Preferably, when matching the parameters of the high-speed aircraft flight profile with the aerodynamic thermal reference flight state, it is necessary to match the flight altitude and speed of the state with the altitude and speed in the flight profile to determine the corresponding time in the flight profile, which serves as the basis for subsequent interpolation to obtain the continuous time-point heat flow of the entire profile.

[0014] Preferably, when performing loading calculations on the heat conduction model based on transient heat flux input, the heat flux input to be loaded is calculated based on velocity and height interpolation for each heat conduction increment step time, and a load is applied to each loading surface.

[0015] Preferably, the nodal force loads for each working condition are formed as follows:

[0016] Based on the flight conditions of the aerodynamic load to be analyzed, determine the flight state in the flight profile where the aerodynamic load appears, and determine the specific time when the flight state appears in the flight profile.

[0017] The aerodynamic loads are processed by interpolating and balancing the aerodynamic loads of each working condition onto the load-bearing skeleton nodes on the finite element model of the body structure to form the nodal force loads used for loading in each working condition.

[0018] In the heat conduction simulation results, search for the incremental step result closest to a given time point, record the number of the incremental step, and extract the temperature field of that incremental step according to time as the operating temperature field.

[0019] The extracted operating temperature field and the aerodynamic load to be calculated are used as load inputs for thermo-mechanical coupling calculation.

[0020] Preferably, when each load-bearing skeleton node is interpolated and balanced with the load, the dense aerodynamic load is interpolated onto the load-bearing skeleton node of the finite element model using the inverse distance interpolation method, and then the load balance is corrected based on the energy method.

[0021] Preferably, high-efficiency batch thermo-mechanical coupling calculation simulation is performed, specifically as follows:

[0022] The input file of the finite element simulation is parsed, and the node, mesh, material, property and connection information in the model are extracted. A proxy data structure of the simulation model is established outside the finite element software. The parameterized loading of nodal forces and global temperature field is realized by automatically reading the load file and the temperature field at a specific time in the proxy data structure.

[0023] Referring to the finite element simulation input file format, a proxy data structure is used to reverse generate the finite element simulation input file. The simulation model information of different working conditions is converted into calculation files for commercial finite element software calculation and simulation. High-efficiency batch thermal coupling calculation and simulation are performed through cmd calls and multi-threaded parallel methods.

[0024] The thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft proposed in this application has the following advantages:

[0025] By employing techniques such as thermal load data matching, analytical generation of simulation models, and batch parallel solving of finite element methods, a reliable, efficient, and standardized solution for simulating the thermal coupling strength of high-speed aircraft with well-defined mission profiles has been achieved. This is of significant value for improving the structural design level of near-space vehicles and reducing their structural weight. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall process of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0028] The first aspect of this application provides a thermo-mechanical condition timing matching method based on a typical mission profile of a high-speed aircraft. First, the strength load is matched with the flight parameters and the flight profile to obtain the time corresponding to the load. Then, the time is matched with the incremental steps of the temperature field to obtain a temperature field with several incremental steps. Each obtained temperature field and the same strength load are respectively input into the force transmission finite element for thermo-mechanical coupling calculation.

[0029] like Figure 1 Specifically, it includes the following steps:

[0030] Step S100: Simulation of thermal conduction in the body structure.

[0031] First, the heat exchange surface for heat conduction simulation is determined, and the heat flow input matching relationship between the heat exchange surface and the finite element model and aerodynamic thermal input file is established. Then, the flight state data (flight speed, altitude, etc.) of the aerodynamic thermal input are compiled to determine the usable reference aerodynamic thermal flight state.

[0032] Secondly, the high-speed aircraft flight profile is parameter-matched with the aerodynamic thermal reference flight state, and interpolation is used to obtain the heat flow input at each time point during the simulation, providing transient input for transient heat conduction calculation simulation. To smooth the heat conduction calculation results, linear interpolation is performed on the flight profile at intervals no greater than 1 / 400 of the total flight time, while different flight states at the same Mach number and altitude should be distinguished.

[0033] When performing parameter matching, the given aerodynamic thermal reference flight state is often a discrete thermal flow state of no more than 10 points. It is necessary to match the flight altitude and velocity of this state with the altitude and velocity in the flight profile to determine its corresponding time in the flight profile, which serves as the basis for subsequent interpolation to obtain the continuous time-point thermal flow of the entire profile.

[0034] By matching the two parameters of altitude and velocity to determine the corresponding time of the reference state in the flight profile, a precise time reference is provided for the interpolation of heat flux at continuous time points across the entire profile. This allows the discrete aerothermal reference state to be effectively connected with the continuous flight profile, avoiding time positioning errors caused by the simplification of parameter matching.

[0035] Finally, a heat conduction simulation model of a high-speed aircraft was constructed (based on the aircraft structural numerical model, a finite element model of the aircraft was constructed, and the analysis type was set to heat conduction analysis). The heat conduction model was loaded and calculated based on transient heat flow input, and the simulation results of the transient temperature field of the whole aircraft were obtained, providing thermal load input for subsequent thermo-mechanical coupling matching simulation calculations.

[0036] When performing loading calculations on the heat conduction model based on transient heat flux input, a secondary development of finite element software was used to calculate the required heat flux input for each heat conduction increment time step based on velocity and height interpolation, and loads were applied to each loading surface. By interpolating the heat flux input for each heat conduction increment time step and applying loads to each loading surface one by one, accurate loading of transient heat flux input in the increment step dimension was achieved.

[0037] By clearly defining the heat flux input matching relationship, limiting the linear interpolation interval (not greater than 1 / 400 of the total flight time), and distinguishing different flight states at the same Mach number and altitude, continuous and accurate transient heat flux input acquisition of the entire flight profile was achieved. This avoids heat flux data distortion caused by excessive interpolation intervals and avoids the problem of heat flux confusion under the same flight parameters for different states.

[0038] Step S200: Perform thermal operating condition timing matching.

[0039] Each working condition to be analyzed is matched with the corresponding time point to achieve coupled loading between the force condition and the temperature field of the heat conduction analysis results.

[0040] First, based on the flight conditions of the aerodynamic load to be analyzed, determine the flight states in the flight profile where the aerodynamic load may appear, and determine the specific time when the flight state appears in the flight profile.

[0041] Secondly, the aerodynamic loads are processed by interpolating and balancing the aerodynamic loads of each working condition onto the load-bearing skeleton nodes on the finite element model of the body structure, forming the nodal force loads (strength force loads) for loading under each working condition.

[0042] During interpolation and load balancing, dense aerodynamic loads are interpolated onto the load-bearing skeleton nodes of the finite element model using methods such as inverse distance interpolation. Load balancing corrections are then performed based on energy methods and a self-developed program, ensuring that the interpolated nodal forces are self-balancing across the entire aircraft scale. The inverse distance interpolation method achieves accurate conversion of dense aerodynamic loads to finite element nodes, making the distribution of aerodynamic loads more closely match the node layout of the finite element model and avoiding uniformity deviations in load interpolation.

[0043] Finally, in the heat conduction simulation results, search for the incremental step result closest to the given time point, record the number of incremental steps, and extract the temperature field of the incremental step (transient temperature field) according to time as the operating temperature field;

[0044] The extracted operating temperature field and the aerodynamic load to be calculated are used as load inputs for thermo-mechanical coupling calculation (the coupling effect of force load and temperature-induced thermal stress load is considered in the calculation).

[0045] By locating the flight state time corresponding to the aerodynamic load, a temporal correlation between the force load and the flight profile is established; by extracting the operating temperature field at the corresponding time point, accurate temporal matching of the force load and thermal load is achieved, enabling thermo-mechanical coupling calculation to simultaneously consider the coupling effect of force load and thermal stress.

[0046] Step S300: Perform batch operating condition timing matching for thermal coupling.

[0047] First, the finite element simulation input file is parsed to extract information such as nodes, meshes, materials, properties, and connections from the model. A proxy data structure for the simulation model is then established outside the finite element software. By automatically reading the load file and the temperature field at a specific time in the proxy data structure, parameterized loading of nodal forces and the global temperature field is achieved.

[0048] Secondly, referring to the finite element simulation input file format, the reverse generation of the proxy data structure into the finite element simulation input file is realized, thereby converting the simulation model information of different working conditions into calculation files that can be used for calculation simulation in commercial finite element software. High-efficiency batch thermal coupling calculation simulation is achieved through cmd calls, multi-threaded parallelism, and other means.

[0049] The process of high-efficiency batch thermo-mechanical coupling calculation simulation is refined and defined. By establishing a proxy data structure outside the finite element software, parameterized loading of nodal forces and global temperature field is realized, eliminating the dependence on the finite element software interface and improving the automation of load loading.

[0050] Because the load involves the coupling effect of two physical fields, the number of operating conditions that need to be calculated is much greater than that of traditional aircraft. To improve simulation efficiency, a multi-threaded parallel method is introduced to perform interfaceless batch simulation calculations.

[0051] To meet the design requirements of multi-stage and multi-level structures, this method designs three matching modes for each thermo-mechanical coupling condition:

[0052] a) Force simulation: This model considers the effects of load and high temperature on material properties, but does not consider thermal stress (achieved by setting the thermal expansion coefficient of all materials to 0). It can be used for structural load-bearing layout and size design.

[0053] b) Thermal Model: This model considers thermal stress but not aerodynamic loads (no nodal force loading). It can be used for thermal mitigation and heat release design.

[0054] c) Thermo-coupling model: This model considers both thermal stress and aerodynamic forces. It can be used for detailed modifications and final strength verification.

[0055] In summary, this application has the following advantages:

[0056] By designing the entire process from determining the heat exchange surface and acquiring the heat flow input, processing aerodynamic loads and forming nodal force loads, parsing finite element files and performing batch simulation calculations, the system systematically realizes the time-series matching and batch simulation of thermal conditions under typical mission profiles of high-speed aircraft. This breaks the traditional manual processing mode of each condition and achieves overall automation and efficiency of thermo-mechanical coupling simulation, significantly reducing the input of human resources.

[0057] As a specific implementation method, the following example illustrates the application, usability, and efficiency of the proposed tools and methods based on the model design scheme. During the force-thermal coupling simulation, the inputs were the finite element model (122910 mesh) from the scheme stage, the 2800s flight profile, and 400 force-thermal coupling simulation calculation conditions and corresponding aerodynamic and thermal loads defined based on the flight state during the scheme evaluation.

[0058] First, based on the structural partitioning in the aerodynamic thermal load, a heat exchange surface is constructed in the finite element model. The flight profile is decomposed into 5-second segments to determine the flight speed and altitude for each segment, thereby identifying two reference state heat flux inputs for calculating heat conduction in each segment. The transient heat input for each flight segment is determined using bilinear interpolation, and loading calculations are performed to obtain the transient temperature field of the flight profile.

[0059] Secondly, based on the flight state in which aerodynamic loads occur, the matching profile time period for this state is determined by interpolation of the flight profile, and the nodal load distribution of the load-bearing components is calculated by combining the whole-aircraft inertial force balance method. The entire flight profile is traversed in time sequence, and the corresponding coupled global temperature is selected for each nodal load distribution in the transient temperature field results.

[0060] Finally, by combining a self-developed parametric batch loading program for simulation file generation and calculation, the entire load matching loading and simulation calculation task was completed on a single machine (8 cores) within 8 hours, requiring almost no manual operation. This represents a computational efficiency improvement of more than three orders of magnitude compared to traditional thermo-coupling simulation analysis based on manual loading. The simulation conditions covered the entire flight profile, and the thermo-conditions were precisely matched according to the time sequence. The simulation results have been verified as reliable, avoiding the weight penalty caused by conservative superposition of load conditions, and can be used in subsequent size optimization and scheme evaluation processes.

[0061] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for timing matching of thermodynamic operating conditions based on typical mission profiles of high-speed aircraft, characterized in that, include: The heat exchange surface for heat conduction simulation calculation is determined, and parameters are matched in conjunction with the flight profile of a high-speed aircraft to obtain the heat flow input at each time point during the simulation; a heat conduction simulation model of a high-speed aircraft is constructed based on the heat flow input. Based on the flight conditions of the aerodynamic loads to be analyzed, the aerodynamic loads are obtained, interpolated, and load balanced to form the nodal force loads for loading under each condition, which are then input into the heat conduction simulation model. The finite element simulation input file is parsed and converted into a calculation file for use in commercial finite element software, in accordance with the finite element simulation input file format, to perform high-efficiency batch thermal coupling calculation simulation.

2. The thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft as described in claim 1, characterized in that, A heat conduction simulation model for a high-speed aircraft is constructed based on the aforementioned heat flow input, specifically as follows: Based on the heat exchange surface, establish the heat flow input matching relationship between the heat exchange surface and the finite element model and the aerothermal input file, organize the aerothermal input flight state data, and determine the reference aerothermal reference flight state; The high-speed aircraft flight profile is matched with the aerodynamic thermal reference flight state, and the heat flow input at each time point during the simulation is obtained by linear interpolation. The linear interpolation is performed on the flight profile at intervals of no more than 1 / 400 of the total flight time, and different flight states at the same Mach number and altitude are calculated separately. A heat conduction simulation model of a high-speed aircraft was constructed. The heat conduction model was loaded and calculated based on transient heat flow input. The simulation results of the transient temperature field of the whole aircraft were obtained, which provided thermal load input for subsequent thermo-mechanical coupling matching simulation calculation.

3. The thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft as described in claim 2, characterized in that, When matching the parameters of a high-speed aircraft flight profile with an aerodynamic thermal reference flight state, it is necessary to match the flight altitude and speed of that state with the altitude and speed in the flight profile to determine the corresponding time in the flight profile, which serves as the basis for subsequent interpolation to obtain continuous time-point heat flux across the entire profile.

4. The thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft as described in claim 2, characterized in that, When performing loading calculations on the heat conduction model based on transient heat flux input, the heat flux input to be loaded is calculated based on velocity and height interpolation for each heat conduction increment step time, and the load is applied to each loading surface.

5. The thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft as described in claim 1, characterized in that, The nodal force loads used for loading under each working condition are formed as follows: Based on the flight conditions of the aerodynamic load to be analyzed, determine the flight state in the flight profile where the aerodynamic load appears, and determine the specific time when the flight state appears in the flight profile. The aerodynamic loads are processed by interpolating and balancing the aerodynamic loads of each working condition onto the load-bearing skeleton nodes on the finite element model of the body structure to form the nodal force loads used for loading in each working condition. In the heat conduction simulation results, search for the incremental step result closest to a given time point, record the number of the incremental step, and extract the temperature field of that incremental step according to time as the operating temperature field. The extracted operating temperature field and the aerodynamic load to be calculated are used as load inputs for thermo-mechanical coupling calculation.

6. The thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft as described in claim 5, characterized in that, When interpolating and balancing the loads at each load-bearing skeleton node, the dense aerodynamic loads are interpolated onto the load-bearing skeleton nodes of the finite element model using the inverse distance interpolation method, and then the load balancing is corrected based on the energy method.

7. The thermodynamic condition timing matching method based on typical mission profiles of high-speed aircraft as described in claim 1, characterized in that, To perform high-efficiency batch thermal coupling calculations and simulations, specifically: The input file of the finite element simulation is parsed, and the node, mesh, material, property and connection information in the model are extracted. A proxy data structure of the simulation model is established outside the finite element software. The parameterized loading of nodal forces and global temperature field is realized by automatically reading the load file and the temperature field at a specific time in the proxy data structure. Referring to the finite element simulation input file format, a proxy data structure is used to reverse generate the finite element simulation input file. The simulation model information of different working conditions is converted into calculation files for commercial finite element software calculation and simulation. High-efficiency batch thermal coupling calculation and simulation are performed through cmd calls and multi-threaded parallel methods.

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