24 results about "Transient heat transfer" patented technology

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 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.

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 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 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 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 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.

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.

The invention discloses a method for checking a wellbore temperature field during cementing based on a random forest algorithm, and relates to the field of oil and gas well cementing engineering, and the method comprises the following steps: establishing a wellbore transient heat transfer model in a cementing process, and setting a value range of a convective heat transfer coefficient correction parameter; randomly generating a plurality of initial parameter combinations, and inputting the initial parameter combinations into a shaft transient heat transfer model for temperature field simulation; calculating a temperature error corresponding to each parameter combination, and constructing an initial training sample set; training a random forest model; predicting the error of each candidate parameter combination by using the trained random forest model, and selecting the first K groups of parameter combinations with the minimum prediction error; verifying and comparing by combining a shaft transient heat transfer model, and determining an optimal convective heat transfer coefficient correction parameter combination; the method is applied to a shaft transient heat transfer model, and the checked shaft temperature field in the cementing process is obtained. The intelligent and efficient optimization of the key parameters of the heat transfer model is realized, and the temperature prediction precision and the model adaptability are improved.

The present application relates to a kind of heat transfer simulation method and system based on shape memory fabric, it is related to shape memory fabric thermal simulation technical field, wherein, method includes: based on the point cloud data of SMF in heat source environment under the calculation of key feature parameters of SMF in complete deformation;Shape memory fabric system is constructed based on SMF, obtains the starting time, completion time of its deformation;Based on key feature parameters, the starting time, completion time of deformation, construct the SMF geometric model for reflecting the deformation process of SMF;Based on SMF geometric model and SMF geometric model related parameters, establish SMF transient heat transfer model;Based on SMF transient heat transfer model, the action law of the physical property parameter of shape memory fabric system to skin temperature and secondary burn time is calculated, to construct prediction equation.The present application prediction equation is used for the design of shape memory fabric SMF and the evaluation of heat transfer performance.

This invention relates to the field of performance simulation and evaluation technology, specifically to a comprehensive performance evaluation method for cryogenic liquid hydrogen ball valves based on an adaptive working condition algorithm. The method includes the following steps: constructing a simulation model, calculating the mesh wetting fraction to generate the fluid-solid wetting state, and outputting the weighted heat flux; inputting the heat flux into heat transfer calculations and fusing hardening parameters to calculate the microscopic peak-valley transient stiffness; combining contact pressure to generate distorted coordinates and constructing nodal plastic deformation; analyzing deformation parameters to extract extreme values, calculating damage contributions, performing fatigue deduction, and constructing a comprehensive evaluation. In this invention, by combining nucleus and film heat transfer mechanisms to deduce energy distribution and restore transient heat transfer boundaries, fusing normal temperature difference to correct the initial modulus, characterizing the cold brittle degradation law of cryogenic materials, relying on microscopic stiffness to analyze pressure mapping distortion to obtain nodal plastic deformation, calculating single-step damage contributions, and performing fatigue evolution analysis to effectively eliminate static mechanical model errors, thus achieving accurate prediction of ball valve performance.

The invention discloses a thick plate core water-air alternate cooling process design method. The method comprises the following steps: 1) sample preparation and temperature measurement; 2) setting a cooling working condition and executing a quenching test; (3) cooling capacity quantification; 4) constructing a transient heat transfer finite element model of the thick plate; 5) checking the model; then performing cooling simulation by adopting the checked model and different water-air alternate cooling process parameters, and determining the water-air alternate cooling process parameters meeting the requirements; (6) verification test and anomaly recognition are carried out, specifically, quenching verification test is carried out through the determined water-air alternate cooling process parameters, and an actually-measured cooling curve of each cooling working condition is obtained; and abnormal data are identified and eliminated by observing the consistency of the actually measured cooling curve, the microstructure and the hardness. According to the method, the change of the thick plate core water-air alternate cooling process design from experience trial and error to quantitative optimization is realized, the test frequency is reduced, the research and development efficiency is improved, meanwhile, the influence of different test condition differences on a conclusion is reduced, and the repeatability is improved.

The application discloses a cleaning degree detection method and device suitable for long-distance refrigeration pipelines, relates to the related technical field of cleaning degree detection, and comprises the following steps: determining the injection gas type and injection pulse signal of the long-distance pipeline to be detected; connecting a liquid nitrogen vaporization device, controlling a pulse injection valve to inject gas into an inlet through the injection pulse signal, collecting the temperature of the outer surface by using an infrared thermal imaging array, and outputting real-time response data of the outer surface temperature; constructing a heat transfer abnormal area identification model through a three-dimensional transient heat transfer equation of the pipeline and marking the abnormal area to obtain the heat transfer abnormal area; and analyzing the heat transfer abnormal response data of the heat transfer abnormal area to generate a cleaning degree detection result. The technical problems that the long-distance refrigeration pipeline cleaning degree detection efficiency is low, real-time dynamic monitoring cannot be realized, and local pollution areas are difficult to accurately identify in the prior art are solved, and the technical effects of accurately positioning the heat transfer abnormal area and efficiently and accurately detecting the cleaning degree of the pipeline are achieved.

The invention discloses a particle-containing liquid milk UHT sterilization heat transfer simulation method and a related device, and relates to the technical field of dairy product sterilization, the method comprises the following steps: based on UHT sterilization equipment parameters and process conditions, constructing a thermal resistance network model comprising a heat conduction and heat convection heat transfer path among superheated water, a pipe wall, cow milk and particles; calculating a fluid side convective heat transfer coefficient based on a thermal resistance network model and an empirical correlation formula, and calculating an actual heat exchange amount according to the actual change of the temperature; the method comprises the following steps: by taking a single particle in particle-containing liquid milk as a research object, establishing a transient heat conduction partial differential equation for describing the change of the internal temperature of the particle along with time and a spherical coordinate system main equation for reflecting the physical change of the particle; simulation parameters and boundary conditions of precooking and sterilization stages are determined, a transient heat conduction partial differential equation and a spherical coordinate system main equation are solved, spatial and temporal distribution of a particle internal temperature field is obtained, and accurate simulation of the particle phase in the internal transient heat transfer process in the rapid variable temperature field is achieved.