41 results about "Transient heat transfer" patented technology

A wellbore temperature optimization and predication method integrating numerical models and machine learning includes the following steps: establishing a wellbore-formation transient heat transfer model, obtaining an initial data set composed of relevant parameters, normalizing the initial data set, training a wellbore temperature prediction model by using a random forest algorithm, then optimizing the hyperparameters of the random forest algorithm by using a genetic algorithm, performing global optimization by using an annealing algorithm to obtain the optimized wellbore temperature and related parameters, calculating the wellbore temperature by substituting the optimized parameters into the wellbore-formation transient heat transfer model, and performing comparative verification on the optimized wellbore temperature and the calculated wellbore temperature.

The invention discloses a method for quickly calculating transient thermal stress of a ceramic radome along a flight path, which comprises the following steps of: determining calculation input which comprises an aerodynamic thermal environment of the ceramic radome and a to-be-evaluated structure scheme; setting a circumferential discrete strategy of the ceramic radome to determine a plurality of meridian planes of the ceramic radome; constructing an aerodynamic thermal environment interpolation model, and determining a meridian plane where aerodynamic heating of the ceramic antenna housing is most strict in the whole flight process; constructing a two-dimensional feature structure model for transient heat transfer and thermal stress analysis of the ceramic radome, and determining an outer contour line of the two-dimensional feature structure model; constructing an axial thermal response calculation interval of the ceramic radome and performing interpolation calculation to obtain aerodynamic thermal environment parameters of the outer contour line at each flight moment; performing heat transfer calculation grid division on the two-dimensional feature structure model, and calculating structure transient temperature distribution of the two-dimensional feature structure model; calculating the temperature gradient of the structure based on the transient temperature distribution of the structure; and calculating transient thermal stress distribution of the ceramic radome by using the structural temperature gradient.

The invention discloses a silicon carbide continuous sintering furnace performance optimization method based on a dynamic grid technology. The method comprises the following steps that a three-dimensional simulation model of a continuous sintering furnace load silicon carbide workpiece is established, unstructured grid division is conducted, and grid encryption treatment is conducted on a heating area, the silicon carbide workpiece and a cooling water system inlet and outlet; performing three-dimensional transient heat transfer calculation, and setting a dynamic area by combining the dynamic grid model to obtain a dynamic temperature field distribution rule of the silicon carbide workpiece in the continuous moving heating process; under different heating belt structures and different temperature setting modes, the temperature difference between the center and the edge and the temperature difference between the front end face and the rear end face of the moving silicon carbide workpiece are compared and analyzed, a heating performance optimization scheme of an original furnace profile is determined, and therefore the temperature uniformity of the silicon carbide workpiece in the furnace is improved. The original furnace profile is optimized on the premise that the structural size of the furnace body is not changed, and the temperature uniformity of the silicon carbide workpiece is remarkably improved.

The invention relates to the technical field of heat energy machinery, in particular to a gas turbine simulation method and device based on multi-physics field coupling and gas compressor transient heat transfer, and the method comprises the steps: coupling one-dimensional complete machine model data with three-dimensional gas compressor model data to obtain coupling data; and an analysis tool based on the multi-physics field coupling transient numerical simulation technology is obtained through development according to the coupling data, simulation prediction is conducted on the performance condition of the gas compressor under the transient convective heat transfer condition based on the analysis tool, and a simulation prediction result is obtained. Therefore, the problems that in the prior art, simulation time is long, model building and solving are relatively complex, and numerical values are unstable due to the action between physical fields are solved.

The invention belongs to the technical field of hypersonic flight vehicle design, and discloses a high-speed wind tunnel precursor and air inlet coupling heating model and a simulation verification method thereof. A heating structure is arranged on the high-speed wind tunnel precursor and air inlet coupling heating model, heating rods in bilateral symmetry are arranged on a sharp front edge, heating plates are arranged on a first-stage compression surface, a second-stage compression surface and a shoulder part, heat insulation grooves are formed between the heating plates, meanwhile, a pressure sensor is arranged on a symmetric center line, and a pressure sensor is arranged in a wall surface below the heating plates. A plurality of temperature measuring points are arranged, and full-area and full-depth temperature measurement is carried out. According to the simulation verification method for the high-speed wind tunnel precursor and air inlet coupling heating model, the effectiveness of thermal protection design is verified through three-dimensional transient heat transfer simulation, the remarkable regulation and control effect of wall temperature changes on a shock wave structure, pressure distribution and turbulence characteristics is revealed through k-omega SST turbulence model numerical simulation, and the method has engineering practical value.

The invention provides a wind driven generator fault diagnosis method, device and equipment and a storage medium, and relates to the technical field of intelligent operation and maintenance of wind power generation equipment. The method comprises the following steps: constructing a thermal network model of the wind driven generator, and obtaining a transient heat transfer equation and a first thermal conductance matrix and a first heat source intensity vector of the wind driven generator in a healthy state based on the thermal network model; according to the first thermal conductance matrix, the first heat source intensity vector and the current temperature of each temperature measurement point of the wind driven generator, performing inversion based on a transient heat transfer equation to obtain a second thermal conductance matrix and a second heat source intensity vector; obtaining a first fault feature matrix according to the second thermal conductivity matrix and the first thermal conductivity matrix, and obtaining a second fault feature matrix according to the second heat source intensity vector and the first heat source intensity vector; and obtaining a fault diagnosis result of the wind driven generator according to the first fault feature matrix, the second fault feature matrix and a preset fault diagnosis model. According to the invention, high-precision fault diagnosis of the wind driven generator can be realized.

The application relates to the technical field of 3D printing process simulation, in particular to a 3D printing process numerical simulation method based on a near-field dynamic method, which comprises the following steps: step one, establishing a near-field dynamic transient heat transfer model; step two, establishing a near-field dynamic living and dead material point model; step three, introducing a near-field dynamic key breaking mechanism; step four, establishing a 3D printing process simulation model based on the near-field dynamic method; step five, defining basic parameters, boundary conditions and initial conditions according to 3D printing process conditions; and step six, simulating calculation and exporting results. In the application, the accumulation of materials in the 3D printing process is regarded as a change process of a scalar field, and 0-1 is used to describe the life and death states of material points in the scalar field, so that the 3D printing process can be described physically in a quite intuitive way; in combination with an explicit calculation method, the calculation amount of each time step in the numerical simulation process is greatly simplified.

The invention discloses a cleanliness detection method and device suitable for a long-distance refrigeration pipeline, and relates to the related technical field of cleanliness detection.The method comprises the steps that the injection gas type and injection pulse signals of a to-be-detected long-distance pipeline are determined; a liquid nitrogen vaporization device is connected, a pulse injection valve is controlled by injecting pulse signals to inject gas into an inlet, an infrared thermal imaging array is adopted to collect the temperature of the outer surface, and real-time response data of the temperature of the outer surface are output; constructing a heat transfer abnormal area identification model through a pipeline three-dimensional transient heat transfer equation, and marking an abnormal area to obtain a heat transfer abnormal area; and analyzing the heat transfer abnormity response data of the heat transfer abnormity area, and generating a cleanliness detection result. The technical problems that in the prior art, the cleanliness detection efficiency of a long-distance refrigeration pipeline is low, real-time dynamic monitoring cannot be achieved, and a local pollution area is difficult to accurately recognize are solved, and the technical effects that the heat transfer abnormal area is accurately positioned, and high-efficiency and high-precision cleanliness detection is conducted on the pipeline are achieved.

The invention relates to a method and equipment for calculating the blood temperature of a patient in hemodialysis treatment, and the method comprises the following steps: obtaining geometric parameters and physical parameters of an extracorporeal circulation pipeline of hemodialysis, so as to establish a transient heat transfer model for representing the spatial-temporal dynamic change of the blood temperature in the extracorporeal circulation pipeline; acquiring operation parameters corresponding to the hemodialysis process, and constraining the transient heat transfer model by using the operation parameters to generate a constrained heat transfer model used for reflecting a heat exchange boundary condition in a real-time dialysis scene; carrying out numerical solution on the constrained heat transfer model so as to generate temperature field distribution data for representing the temperature of each part in the extracorporeal circulation pipeline under the preset dialysis duration; and extracting a temperature value corresponding to the position of the blood outlet of the extracorporeal circulation pipeline as the temperature of the blood outlet. The device has the advantage of better maintaining heat balance and safety of a patient in the treatment process.

The invention discloses a buried pipe group heat transfer simulation method considering hydraulic-geological boundary geometric mismatch, and belongs to the technical field of geotechnical engineering and underground energy storage. The method comprises the following steps: identifying a spatial relationship between an underground water level interface and a geological layering interface based on a geometric algorithm, executing in-layer sub-layer discretization processing, and generating a calculation sub-layer sequence with a hydraulic attribute mark; whether geometric mismatch exists or not is judged by comparing the depth of the top and bottom plates of each geological layer with the buried depth of the underground water level; constructing a composite analytic calculation model, and performing full space-time coupling solution on the transient thermal network in the borehole and the external heterogeneous moving finite line source field; and outputting a long-term thermal response prediction result, and performing optimization evaluation on the buried pipe system layout based on prediction data. According to the method, the complex boundary condition that the underground water level line does not coincide with the geological stratified interface is accurately described, and full coupling calculation of transient heat transfer in the pipe and stratified non-uniform convection-diffusion heat transfer outside the pipe is achieved.

The invention discloses a testing system and method for measuring the specific heat capacity of fluid under high-temperature and high-pressure conditions, and belongs to the technical field of petroleum engineering. The test system comprises a water loss meter, a test assembly and a specific heat data processing system, the testing assembly comprises a slurry cup body, an upper cover, a bottom cover, a bidirectional binding post and a pressurizing interface which are arranged on the upper cover, a probe assembly which is arranged at the top of the slurry cup body and extends into the slurry cup body, and a thermocouple arranged on the bottom cover; the pressurization interface is communicated with an air delivery valve rod of the water loss instrument, an outer binding post and an inner binding post of the bidirectional binding post are electrically connected with the specific heat data processing system and the probe assembly respectively, and an outer coupling interface of the water loss instrument is electrically connected with the thermocouple and the specific heat data processing system respectively. According to the specific heat capacity testing method based on the secondary testing system, time correction is introduced, so that accurate measurement of thermophysical parameters of high-temperature and high-pressure fluid can be achieved, meanwhile, a shaft-stratum transient heat transfer model is established, and the accuracy of measured specific heat capacity data is verified.

This invention relates to the field of heat flux technology and provides a novel wall heat flux partitioning model based on bubble merging behavior and the evaporation region. Spatially, the model divides the wall into a non-bubble-affected region, a nucleation point region, a bubble sliding region, and an evaporation region. Temporally, it divides the bubble nucleation cycle into bubble waiting time and bubble generation time, and the bubble sliding cycle into transient heat transfer-dominated time and one-way convective heat transfer-dominated time. Based on this spatiotemporal partitioning, the total wall heat flux is composed of quenching heat transfer caused by bubbles leaving the nucleation point, transient heat transfer caused by sliding bubbles, evaporation heat transfer during bubble growth, one-way convective heat transfer in the non-bubble-affected region, and steam heat transfer in the evaporation region. The total wall heat flux is expressed as: [Formula omitted for brevity]. This model can accurately predict the wall heat flux during the nucleation boiling stage and successfully predict the occurrence of the critical heat flux density.

The application relates to a method and device for intelligent hole-forming design of a medium-deep buried pipe and electronic equipment, wherein the method comprises the following steps: collecting a measured mud inflow temperature and a measured return mud temperature of a target medium-deep buried pipe in a construction drilling process; determining a hypothetical drilling depth according to an actual engineering progress, and generating underground soil temperature distribution information; obtaining a predicted return mud temperature based on a pre-constructed two-dimensional transient heat transfer numerical model of a drilling process column coordinate, calculating an absolute deviation value, correcting the underground soil temperature distribution, and reconstructing a geothermal field until the absolute deviation value is smaller than a preset deviation threshold; calculating a heat extraction amount of the buried pipe based on a pre-constructed buried pipe heat transfer numerical model and the geothermal field, adjusting the hypothetical drilling depth, and determining the depth and quantity of the buried pipe until the heat extraction amount exceeds a preset design value. Thus, the problems of drilling depth redundancy or deficiency, high construction cost, significant geothermal field prediction deviation and the like caused by systematic errors in depth setting in the related art are solved.

The invention discloses a transient heat transfer coefficient calculation method based on an immersion boundary method. At present, in the transient starting and stopping process of a steam turbine system, thermal parameters such as the flow, the pressure and the flowing direction of fluid need to be dynamically adjusted. The method comprises the following steps that a computational domain model needing to be studied by the adjusting mechanism in the fluid calculation process is established; establishing a fluid domain grid model and a solid domain grid model of the adjusting mechanism; according to the start-stop curve, in combination with a stroke flow curve of the adjusting mechanism, thermal parameters of different working conditions under the variable load are determined; setting boundary conditions of the fluid domain; according to the basic principle of fluid heat exchange and based on an immersion boundary method, the transient heat exchange coefficient of the opening degree of a movement module of the adjusting mechanism in the changing process from large to small is calculated; determining a heat exchange coefficient extraction form, and extracting a transient heat exchange coefficient result; selecting typical points on the wall surface of the fluid-solid coupling research object, observing the time-domain change track of the heat exchange coefficient, and performing comparative analysis. The method is used for calculating the transient heat transfer coefficient.

The invention provides a medium-temperature turbine blade double-flow coupling heat transfer test wind tunnel experiment system which is of a direct-current heat transfer wind tunnel structure. Comprising a test section with a built-in to-be-tested turbine blade model, a main flow pipeline for providing stable heating air for the test section, and a secondary flow pipeline for reversely heating the test section, the airflow discharge pipeline is used for discharging airflow provided by the main flow pipeline and the secondary flow pipeline from the test section; the outlet of the main flow pipeline, the outlet of the secondary flow pipeline and the inlet of the airflow discharge pipeline are detachably connected with the tail end of the pipeline of the test section through flanges; the method has the beneficial effects that transient heat transfer measurement, steady-state heat transfer measurement and coupling heat transfer measurement can be carried out, and the heat transfer characteristics of the whole blade can be measured; and the structure is reliable, high-stability and high-uniformity airflow can be provided, and a reference basis is provided for advanced cooling design of the gas turbine.

The invention discloses a method for simultaneously measuring the specific heat capacity and the surface heat flux density of a solid-liquid phase change material and a storage medium. The method comprises the following steps: S1, establishing an internal coupling heat transfer model of the solid-liquid phase change material; s2, laser is used for heating the surface of the solid-liquid phase change material to measure the temperature; s3, solving a transient heat transfer model; s4, establishing input signals em, n and a particle individual fitness function Fl for simultaneously measuring the specific heat capacity and the surface heat flux density of the solid-liquid phase change material; s5, constructing a hybrid optimization module; s6, the specific heat capacity and the surface heat flux density of the solid-liquid phase change material are updated; s7, checking whether an iteration stop condition is reached or not; and S8, recording the specific heat capacity and the surface heat flux density of the new solid-liquid phase change material at the moment, and outputting as a measurement result. The storage medium is used for storing a computer program for executing the method. The method has the advantages of simple principle, simplicity and convenience in operation, high error interference resistance and the like.

The invention discloses a hot dry rock resource quantity evaluation method, apparatus and device, and a storage medium. The method comprises the steps of establishing a regional three-dimensional geological model based on geological data information of a target region; establishing a transient heat transfer equation, and determining boundary conditions of the regional three-dimensional geologic model according to supply information and loss information of the hot dry rock in the target region; carrying out numerical simulation by utilizing a finite element method based on the boundary condition and the transient heat transfer equation to obtain a simulation result; and selecting the hot dry rock reservoir from a simulation result, and evaluating the hot dry rock resource quantity of the hot dry rock reservoir by utilizing a self-adaptive heat storage volume method. According to the method, the boundary condition of the regional three-dimensional geologic model is determined according to the supply information and the loss information of the hot dry rock in the target region, then numerical simulation is carried out by utilizing the finite element method based on the boundary condition and the transient heat transfer equation, and finally the hot dry rock resource quantity is evaluated by utilizing the self-adaptive heat storage volume method. And the accuracy of evaluating the hot dry rock resource quantity is effectively improved.

A three-dimensional layered semi-infinite foundation transient heat transfer stress coupling numerical analysis method comprises the steps that a semi-infinite domain is divided into a near-field area and a far-field area, coordinate transformation is established based on geometric similarity between similar surfaces and boundary surfaces, and a proportional boundary finite element coordinate system is formed; deriving a heat conduction and thermal stress control equation under an SBFEM coordinate system based on a variational principle and a virtual work principle, and establishing a dimensionless heat conduction matrix under a frequency domain; solving a heat conduction matrix by adopting a continuous fractional expansion method and Scherr decomposition, and realizing time domain integration through an improved fine time-history integration method (MPTSIM); under a sequential coupling framework, firstly solving a transient temperature field, and then applying the transient temperature field as a thermal load to a mechanical equilibrium equation to obtain a displacement field and a stress field; according to the method, the calculation scale and resource consumption are remarkably reduced while high precision is guaranteed, and the method is suitable for efficient analysis of the transient thermal-mechanical coupling problem in the three-dimensional layered semi-infinite foundation.

The invention provides a porous material heat insulation performance test system and prediction method based on physical prior learning, and belongs to the technical field of heat insulation performance prediction.The porous material heat insulation performance prediction method based on physical prior learning comprises the steps that the porous material heat insulation performance test system is built; the method comprises the following steps: acquiring experimental data of a to-be-tested porous material based on a porous material heat insulation performance testing system, and constructing a one-dimensional transient heat transfer physical model based on a one-dimensional transient heat transfer physical problem formed by the experimental data of the to-be-tested porous material; according to the one-dimensional transient heat transfer physical model, building a physical heuristic neural network model with the heat insulation performance prediction capability, and training the physical heuristic neural network model with the heat insulation performance prediction capability to realize heat insulation performance prediction of the porous material; according to the method, global temperature field reconstruction and thermophysical property parameter identification can be realized at the same time under a limited number of measurement point data of an experiment, so that the experiment cost is reduced, and the prediction efficiency is remarkably improved.

The present application belongs to the technical field of metal additive manufacturing and solidification structure regulation, and particularly relates to a laser powder bed fusion forming method of a directional columnar grain structure alloy. The present application adopts a flat-top beam or a point-ring beam as a forming laser beam, inputs a single-channel three-dimensional transient heat transfer solidification model, obtains a molten pool width, a molten pool depth, a temperature gradient, a solidification rate and a columnar grain-equiaxed grain transition determination result, screens laser power and scanning speed according to the molten pool morphology with a width-depth ratio W / D>3; sets a scanning interval according to the deviation area of the molten pool side temperature gradient vector relative to the preset columnar grain growth direction, so that the overlapping area of adjacent melt channels covers different orientation dendrites or grains on the side; sets the powder layer thickness according to the sensitive area of the columnar grain-equiaxed grain transition at different heights, so that the remelting of the subsequent layer molten pool eliminates the mixed crystals, equiaxed crystals or non-target oriented grains on the top of the previous layer molten pool, and a columnar grain structure metal alloy component is obtained through continuous directional growth across the melt channel and across the layer.

This application provides a 3D modeling method and system for manufacturing liquefied natural gas (LNG) ship pipe fittings. The method assigns material properties to each component of the 3D geometric model of a double-walled LNG ship pipe. Then, in the 3D modeling environment, a transient heat transfer-thermoelasticity bidirectional coupling analysis is performed to obtain time-series data of the normal relative displacement of the inner and outer pipes. Based on this time-series data, an effective gap dynamic distribution field is determined. The gap value at each moment in the effective gap dynamic distribution field is compared with a preset allowable compression margin threshold for the insulation layer to form a set of potential insulation failure risk points. Using this set of potential insulation failure risk points as constraints, the geometric dimensions or axial spacing of the support blocks in the region containing the potential insulation failure risk points are automatically adjusted to generate an optimized 3D model of the double-walled pipe. Using this solution, the transient insulation failure risk of the double-walled pipe during the entire cooling process can be eliminated during the 3D modeling stage.

The present invention belongs to the technical field of hypersonic vehicle design, and discloses a coupled heating model of a high-speed wind tunnel forebody and an inlet, and a simulation verification method therefor. A heating structure is provided on the coupled heating model of the high-speed wind tunnel forebody and the inlet. Heating rods that are symmetric about the left and right are arranged on the sharp leading edge, heating plates are arranged on the first-stage compression surface, the second-stage compression surface and the shoulder, heat insulation grooves are arranged between the heating plates. At the same time, pressure sensors are arranged on the symmetry center line, and a plurality of temperature measurement points are arranged in the wall surface below the heating plates to perform full-area and full-depth temperature measurement. The simulation verification method of the coupled heating model of the high-speed wind tunnel forebody and the inlet uses three-dimensional transient heat transfer simulation to verify the effectiveness of the thermal protection design, and k-ω the numerical simulation of the SST turbulence model reveals the significant regulation effect of the wall temperature change on the shock wave structure, pressure distribution and turbulence characteristics, and has engineering practical value.

The present invention provides a deviation design method for a medium-deep coaxial casing heat exchanger, comprising the following steps: Step 1: Establish a transient heat transfer model of the medium-deep coaxial casing heat exchanger and the rock and soil mass, and obtain the temperature distribution of the rock and soil mass; Step 2: Determine the maximum thermal influence radius R of the medium-deep rock and soil mass max ; Step 3: Design the deviation angle θ of the medium-deep coaxial casing heat exchanger d ; The deviation design method of the medium-deep coaxial casing heat exchanger, a design method for a new installation form of the medium-deep coaxial casing heat exchanger - the deviation installation form, reasonably designs the installation form and angle of the heat exchanger on the premise of maximizing the avoidance of thermal interference between adjacent heat exchangers, reduces the wellhead distance between adjacent heat exchangers, and is of great significance for reducing the project land area and reducing the ground pipeline heat loss

The invention discloses a composite material aero-engine large-size blade multi-scale solidification analysis method, and relates to the field of aero-engine composite material part manufacturing, and the method comprises the steps: importing a pre-configured composite material aero-engine blade model into finite element analysis software, and carrying out mesh generation; giving parameters to the homogenized composite material, performing transient heat transfer analysis, and defining a temperature boundary condition, a third-class heat boundary condition and a heat generation rate of a boundary node to obtain a macroscopic model; performing blade curing degree field solving and thermal coupling analysis on the macroscopic model to obtain a temperature curve, a curing degree curve and residual stress of the macroscopic model, and embedding a representative volume unit in a macroscopic high-stress area; and constructing a representative volume element model and defining a fiber and resin material constitutive model. The method depends on finite element simulation and algorithm optimization, the number of physical experiments is greatly reduced, the research and development cost is reduced, and the development efficiency is improved.

The application discloses a kind of ceramic radome transient thermal stress fast calculation method along flight trajectory, comprising: determining calculation input, including the aerodynamic thermal environment of ceramic radome and the structure scheme to be evaluated;Set the circumferential discrete strategy of ceramic radome, to determine the multiple meridional plane of ceramic radome;Interpolation model is constructed to aerodynamic thermal environment, determines the most severe meridional plane of ceramic radome aerodynamic heating in flight;Build the two-dimensional feature structure model of ceramic radome transient heat transfer and thermal stress analysis, and determine the external contour line of two-dimensional feature structure model;The axial thermal response calculation interval of ceramic radome is constructed and interpolation calculation is carried out, and the aerodynamic thermal environment parameter of each flight time of external contour line is obtained;The heat transfer calculation grid division is carried out to two-dimensional feature structure model, and the structure transient temperature distribution of two-dimensional feature structure model is calculated;Based on the structure transient temperature distribution, calculate structure temperature gradient;Utilize structure temperature gradient to calculate the transient thermal stress distribution of ceramic radome.

In order to address the shortcomings of the existing conventional transient heat transfer coefficient measurement method, the temperature measurement method is extended from narrow-band thermochromic liquid crystal to other non-contact temperature measurement methods, such as infrared thermal imagers, etc. The present invention proposes a transient solid wall surface heat transfer coefficient measurement method with wide applicability, further derives the non-steady-state thermal conductivity formula of a one-dimensional semi-infinite plate, and promotes the application of the fixed temperature measurement time method applicable to narrow-band thermochromic liquid crystal. The wall temperature measurement value is not limited, and the heat transfer coefficient can be calculated based on the temperature value measured at any time. Compared with narrow-band thermochromic liquid crystal, this method has better versatility and can be applied to non-contact temperature measurement equipment such as infrared thermal imagers whose temperature measurement accuracy is lower than that of narrow-band thermochromic liquid crystal. It also reduces the difficulty of experimental preparation and operation, and by increasing the initial temperature difference (T m ‑T i ) and comprehensive analysis of multiple groups of measurement data over a period of time to ensure the measurement accuracy of the heat transfer coefficient, which is more conducive to the promotion of non-contact temperature measurement technologies such as infrared thermal imagers.

The method for predicting the temperature field of a fire-corroded beam based on a physical information neural network belongs to the field of post-fire structural temperature field analysis technology. It includes the following steps: (1) constructing a heat transfer model; (2) constructing a simplified rust expansion cracking model; (3) constructing a physical information neural network model; (4) training and evaluating the network; and (5) detecting the temperature field of the fire-corroded beam section using the physical information neural network model. This invention improves local prediction accuracy by introducing an adaptive importance sampling and interface focusing training strategy to dynamically densify sampling points in rust expansion cracks and high-temperature gradient regions. Simultaneously, it embeds control equations, latent heat of phase change, and complex boundary conditions into the model to achieve transient heat transfer modeling under the coupled effects of fire and water spray cooling. By enhancing the physical consistency of different material interfaces through heat flow continuity constraints, it significantly improves the accuracy and stability of temperature field prediction under complex working conditions while ensuring computational efficiency.

A numerical analysis method for transient heat transfer and stress coupling in three-dimensional layered semi-infinite foundations is proposed. This method involves dividing the semi-infinite domain into near-field and far-field regions, establishing a coordinate transformation based on the geometric similarity between similar surfaces and boundary surfaces, and forming a scaled boundary finite element coordinate system. Based on variational and virtual work principles, the governing equations for heat conduction and thermal stress are derived in the SBFEM coordinate system, and a dimensionless heat conduction matrix in the frequency domain is established. The heat conduction matrix is ​​solved using continuous fractional expansion and Schul decomposition, and time-domain integration is achieved through an improved refined time history integration method (MPTSIM). Within a sequential coupling framework, the transient temperature field is first solved, and then applied as a thermal load to the mechanical equilibrium equations to obtain the displacement and stress fields. This method significantly reduces computational scale and resource consumption while maintaining high accuracy, and is suitable for the efficient analysis of transient thermo-mechanical coupling problems in three-dimensional layered semi-infinite foundations.

This invention discloses a method for analyzing fluid temperature distribution in a U-shaped medium-deep buried pipe heat exchanger, belonging to the field of ground source heat pump technology. This invention assumes that the fluids in the injection well, production well, and connecting well of the U-shaped medium-deep buried pipe heat exchanger satisfy a one-dimensional heat transfer equation along the flow direction. It also assumes that the backfill material and surrounding soil in the three wells satisfy a one-dimensional radial heat conduction perpendicular to the fluid flow direction, and ignores the heat capacity of the insulation material. Then, a one-dimensional transient heat transfer equation for the fluid is established, and the heat transfer process in the backfill material and soil is analyzed based on an analytical model, thereby establishing a semi-analytical heat transfer model. Finally, the fluid is divided into several nodes along the flow direction, the simulation time is divided into several time nodes, the relevant equations are discretized into algebraic equations, and the iterative method is used to calculate the distribution of fluid temperature with time and space. This invention features simple modeling, low computational load, and high computational accuracy, and has high promotional value.

A transient heat transfer topology optimization method and system for truss structures based on isogeometric stiffness diffusion method, which relates to the field of engineering structure topology optimization design, and is proposed to improve the thermal protection performance of truss structures in unsteady thermal environments. Project the heat conduction and heat capacity matrices of bar elements onto the weak material isogeometric background mesh to construct an isogeometric transient heat transfer finite element model of the truss structure; use an interior point method that combines linear search and trust region optimization strategies to update the iterative design variables and seek the optimal layout design of the truss structure; construct an isogeometric transient heat transfer finite element model of the truss structure; use the trust region-based moving asymptote method to update the iterative design variables and seek the optimal layout design of the truss structure; according to the minimum size constraints of parameters such as the cross-section and length of bar elements, reconstruct the optimal layout of the truss structure to obtain a truss structure design layout that is convenient for engineering applications. The present invention is used for the layout optimization design of truss structures under transient heat flux loads.