Concrete cave wall temperature field acquisition method and system based on fluid heat transfer coupling

Abstract

The invention discloses a concrete cave wall temperature field acquisition method and system based on fluid heat transfer coupling. The method comprises the steps that a concrete wind tunnel fluid heat transfer coupling model comprising a building model, a structure model and a fluid calculation model is constructed to achieve simulation calculation of a concrete tunnel wall temperature field, and multi-dimensional coupling of building, structure type and fluid calculation is achieved; key geometric feature nodes are extracted based on a building model to form a key topological structure, secondary geometric feature nodes are generated on the basis of the key topological structure, irrelevant or redundant nodes in a fluid heat transfer coupling model are eliminated, the complexity of the model is greatly reduced, and the fluid calculation precision is guaranteed; according to the scheme, the secondary geometric feature nodes are generated from the spatial dimension, so that the finally obtained concrete tunnel wall temperature field is the temperature field of the spatial dimension, and the large wind tunnel building with the multi-dimensional heat transfer characteristic can be met.

Description

Technical Field

[0001] The invention relates to the technical field of wind tunnel building design, and in particular to a method and system for acquiring a temperature field of a concrete tunnel wall based on fluid heat transfer coupling. Background Art

[0002] For large wind tunnels, the tunnel wall is usually the side wall of the building. Functionally speaking, it is both an experimental device and a building structure. In the design of the building structure, it is necessary to consider various safety factors and functional requirements in conventional design, and to meet the process requirements and load requirements of the wind tunnel equipment. Temperature is an important control factor that cannot be ignored. During the operation of the wind tunnel, the fan will generate a lot of heat. The heat acts on the tunnel wall along with the flow of air, causing the temperature of the tunnel wall in direct contact with the airflow to rise rapidly, and transfers heat to the outside of the tunnel wall through heat conduction, generating a gradient temperature difference along the tunnel wall to the outside; after the fan stops working, the air in the tunnel will gradually cool down; when the wind tunnel is working, the temperature in the tunnel rises, and after it stops working, the temperature in the tunnel drops, and the cycle repeats to form an alternating temperature field.

[0003] There is no mature and unified engineering approach to how to determine the temperature effect in large wind tunnel buildings, how to establish a structural analysis model that can reasonably consider gradient or even nonlinear temperature effects and conduct structural design.

[0004] The flow of air in a large wind tunnel building and its heat transfer with the large wind tunnel building form a coupled relationship. For the airflow, the temperature of the airflow shows a downward trend in the entire process from the fan outlet to the fan inlet. The main reason is that in the early stage of the experiment, the temperature of the enclosure structure is low, which can absorb the heat in the high-temperature air, causing the airflow temperature to decrease and the enclosure structure temperature to increase. As the enclosure structure absorbs more and more heat, its heat absorption and cooling capacity gradually decreases. Therefore, the cooling process of the airflow by the enclosure structure has a time dimension, that is, as the operating time increases, the effect of the air being cooled by the enclosure structure becomes worse and worse.

[0005] For the enclosure structure, there are heat transfer characteristics in two dimensions: time and space. In terms of time, as the operating time increases, the temperature of the enclosure structure becomes higher and higher, and its absorption capacity gradually decreases. In terms of space, the enclosure structure has two directions of radial heat transfer and axial heat transfer. Radial heat transfer is the heat transferred from the high-temperature airflow to the cave body, which gradually penetrates into the cave body along the radial direction, resulting in obvious temperature non-uniformity on the wall of the cave body in the radial direction, that is, the temperature of the inner surface of the cave body is very high, but as the radial thickness increases, the temperature drops rapidly, resulting in a large temperature gradient in the thickness direction of the cave body; in terms of the axial direction, the upstream part of the cave body first contacts with the high-temperature airflow and absorbs more heat. In the downstream part, the air temperature has dropped, the heat transfer intensity between the air and the cave body is reduced, and the heat absorbed by the cave body is small.

[0006] From the above analysis, it can be seen that during the operation of the wind tunnel, the temperature field inside the wind tunnel changes with a large amplitude (far exceeding the ambient temperature) and a short change time, which significantly differs from the ambient temperature in the temperature change of the main structure. The temperature distribution inside the building structure of a large wind tunnel under a short-term alternating temperature field is difficult to quantitatively determine. The flow of air and the heat transfer between the tunnel bodies are multi-factor coupled, and there are multi-dimensional characteristics in space and time, which cannot be analyzed by simple analytical methods. Summary of the invention

[0007] The technical problem to be solved by the present invention is that the traditional temperature analysis method is mainly applicable to the single-dimensional heat transfer characteristics of temperature, and the obtained temperature distribution is low-dimensional, which cannot be applied to the scene in which the temperature has multi-dimensional heat transfer characteristics in large wind tunnel buildings; the purpose of the present invention is to provide a method for obtaining the temperature field of the concrete cave wall based on fluid heat transfer coupling, and to improve the method on the basis of the traditional temperature analysis technology; on the one hand, this scheme constructs a concrete wind tunnel fluid heat transfer coupling model including a building model, a structural model and a fluid calculation model to realize the simulation calculation of the concrete cave wall temperature field, realize the multi-dimensional coupling of building, structure and fluid calculation, and solve the data barrier problem existing in the transmission of different models; on the other hand, This scheme extracts key geometric feature nodes based on the building model to form a key topological structure, and generates secondary geometric feature nodes based on the key topological structure; at the same time, the key geometric feature nodes and secondary geometric feature nodes are retained, and irrelevant or redundant nodes in the fluid heat transfer coupling model are eliminated, which greatly reduces the complexity of the original model. At the same time, the accuracy of fluid calculation is guaranteed by the key geometric feature nodes and secondary geometric feature nodes; at the same time, the secondary geometric feature nodes generated by this scheme are not nodes of plane dimension, but nodes of space dimension. Finally, the concrete cave wall temperature field obtained based on the simplified fluid heat transfer coupling model is a temperature field of space dimension, which can meet the needs of large-scale wind tunnel buildings with multi-dimensional heat transfer characteristics.

[0008] The present invention is achieved through the following technical solutions: This solution provides a method for obtaining the temperature field of the concrete cave wall based on fluid heat transfer coupling, including: Constructing a fluid heat transfer coupling model of a concrete wind tunnel, wherein the fluid heat transfer coupling model includes: an architectural model, a structural model and a fluid calculation model, and constructing a fluid calculation model of a concrete wind tunnel; Extracting key geometric feature nodes based on the building model to form a key topological structure, and generating secondary geometric feature nodes based on the key topological structure; Retaining key geometric feature nodes and secondary geometric feature nodes, and simplifying the fluid heat transfer coupling model in combination with a fluid calculation model; The boundary conditions are configured, and the temperature field of the concrete cavity wall is obtained based on the simplified fluid heat transfer coupling model.

[0009] Working principle of this scheme: This scheme makes methodological improvements based on traditional temperature analysis technology; on the one hand, this scheme constructs a concrete wind tunnel fluid heat transfer coupling model that includes a building model, a structural model, and a fluid calculation model to realize the simulation calculation of the concrete tunnel wall temperature field, realize the multi-dimensional coupling of building, structural and fluid calculations, and solve the data barrier problem existing in the transmission of different models; on the other hand, this scheme extracts key geometric feature nodes based on the building model to form a key topological structure, and generates secondary geometric feature nodes based on the key topological structure; at the same time, the key geometric feature nodes and secondary geometric feature nodes are retained, and irrelevant or redundant nodes in the fluid heat transfer coupling model are eliminated, which greatly reduces the complexity of the original model. At the same time, the accuracy of fluid calculation is guaranteed by key geometric feature nodes and secondary geometric feature nodes; at the same time, the secondary geometric feature nodes generated by this scheme are not nodes of plane dimension, but nodes of space dimension. Finally, the concrete tunnel wall temperature field obtained based on the simplified fluid heat transfer coupling model is a temperature field of space dimension, which can meet the needs of large wind tunnel buildings with multi-dimensional heat transfer characteristics.

[0010] A further optimization scheme is that the fluid heat transfer coupling model of the concrete wind tunnel is constructed, including the following method: An architectural model of the concrete wind tunnel is constructed according to the shape parameters of the concrete wind tunnel and the shapes of the internal components, and a structural model of the concrete wind tunnel is constructed according to the material parameters and mechanical parameters; a fluid calculation model including a turbulence calculation model and control equations is constructed, and the control equations include: a mass conservation equation, a momentum conservation equation, and an energy conservation equation.

[0011] A further optimization scheme is that the method for constructing the building model includes: The reinforced concrete structure area and the steel structure area of ​​the concrete wind tunnel are divided; the reinforced concrete structure area is modeled according to the actual thickness; the steel structure area is modeled according to the plane: the heat transfer resistance is converted according to the thickness of the steel material in the steel structure area, and a plane model of the steel structure area is constructed; the heat transfer resistance is input into the plane model to obtain the building model of the steel structure area; The internal components in the concrete wind tunnel are modeled according to the abstract structure: the adiabatic wall model is used as the architectural model of the guide vane; the internal cold source model is used as the architectural model of the heat exchanger.

[0012] A further optimization scheme is that the key geometric feature nodes are extracted based on the building model to form a key topological structure, and secondary geometric feature nodes are generated based on the key topological structure; including the method: Dividing the building model into multiple sub-structure blocks according to the structure, obtaining boundary nodes of different surfaces of each sub-structure block, and using the remaining boundary nodes after removing duplicate boundary nodes as key geometric feature nodes, connecting all the key geometric feature nodes to form a key topological structure; Secondary geometric feature nodes are generated based on each sub-structure block: a first threshold value E1 is set. When the distance between two adjacent key geometric feature nodes is greater than the first threshold value E1, m secondary geometric feature nodes are determined between the two key geometric feature nodes. Different sub-structure blocks have different architectural structures and functions, so different first threshold values ​​E1 are set according to the situation when determining the secondary geometric feature nodes.

[0013] Take m secondary geometric feature nodes and all key geometric feature nodes as target points, and construct candidate point sets for each target point: construct a unit sphere with the target point as the sphere center, obtain the inscribed z-hedron of the unit sphere, where z is an even number; divide each face of the inscribed z-hedron into z / 2 triangles and project them radially onto the unit sphere surface; use the centroid of the z / 2 triangles to form the candidate point set of the target point; The eigenvalue of each candidate point is calculated, and the secondary geometric feature nodes are determined from each candidate point set based on the eigenvalue.

[0014] A further optimization scheme is that the building model is divided into a plurality of sub-structure blocks according to the structure, and the boundary nodes of different surfaces of each sub-structure block are obtained, including the method: The building model is divided into multiple sub-structure blocks according to the structure: concrete cave structure block, steel structure grid structure block, top plate steel beam structure block, hanger structure block and support structure block; Obtain all surfaces of each substructure block, and determine all vertices connected to at least three surfaces as boundary nodes; The tangent plane is fitted for any point P and its neighboring points on each surface using the least squares method. Point P and its neighboring points are projected onto the tangent plane, and a vector is obtained with the projection point of point P as the starting point and the projection point of the neighboring point as the end point. The angle between each adjacent vector is obtained, and the maximum angle δ between adjacent vectors is screened out. max ; Compare the maximum angle δ between adjacent vectors max and the angle threshold, if the maximum angle δ max If the angle is greater than the angle threshold, the corresponding neighborhood point is determined as a boundary point.

[0015] A further optimization scheme is that the characteristic value of each candidate point is calculated, and the secondary geometric characteristic nodes are determined from each candidate point set based on the characteristic value, including the method: The eigenvalue K of candidate point i is calculated based on the following formula i : ; Among them, S i(*) represents the expected value of the midpoint * of the triangle where the candidate point i is located; p bi represents the first vertex in the triangle where the candidate point i is located; p ai represents the second vertex in the triangle where the candidate point i is located; p ci Represents the third vertex in the triangle where the candidate point i is located; Set the feature threshold interval and select the candidate points whose feature values ​​are within the feature threshold interval as secondary geometric feature nodes.

[0016] A further optimization scheme is to retain the key geometric feature nodes and the secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with the fluid calculation model; including the method of: eliminating all nodes other than the key geometric feature nodes and the secondary geometric feature nodes in the building model; obtaining all required parameters in the calculation process of the fluid calculation model, and eliminating all parameters other than the required parameters in the structural model.

[0017] A further optimization scheme is that the boundary conditions are configured to obtain the temperature field of the concrete cavity wall based on a simplified fluid heat transfer coupling model; including the following method: Meshing the simplified building model; Different working conditions and boundary conditions are set, and the fluid heat transfer coupling model is parameter-coupled along the direction from the wind tunnel entrance to the wind tunnel exit. The fluid calculation is performed on each grid based on the k-epsilon turbulence equation and the fluid calculation model, and the control equation is solved based on the finite volume method. Finally, the airflow temperature distribution and velocity distribution of the fluid on the surface of the concrete tunnel wall are obtained. The temperature field of the concrete cave wall is obtained based on the air flow temperature distribution and velocity distribution.

[0018] A further optimization scheme is to mesh the simplified building model; including the following method: The reinforced concrete structure area of ​​the building model is divided into multiple cubic grids: the grid accuracy of the fluid inlet, fluid outlet, internal parts and areas for distinguishing different materials is set to the same as that of the reinforced concrete structure area; the number of cubic grids divided along the thickness direction of the reinforced concrete structure area is at least 6, and the side length of the cubic grid is 30mm~80mm; Divide the steel structure area of ​​the building model evenly into multiple squares.

[0019] This solution also provides a concrete cave wall temperature field acquisition system based on fluid heat transfer coupling, which is used to implement the above-mentioned concrete cave wall temperature field acquisition method based on fluid heat transfer coupling; the system includes: A model building module is used to build a fluid heat transfer coupling model of a concrete wind tunnel, wherein the fluid heat transfer coupling model includes: an architectural model, a structural model and a fluid calculation model, and a fluid calculation model of a concrete wind tunnel is built; A node extraction module, used to extract key geometric feature nodes based on the building model to form a key topological structure, and generate secondary geometric feature nodes based on the key topological structure; A simplification module, used to retain key geometric feature nodes and secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with a fluid calculation model; The output module is used to configure boundary conditions and obtain the temperature field of the concrete cavity wall based on the simplified fluid heat transfer coupling model.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides a method for acquiring the temperature field of a concrete cave wall based on fluid heat transfer coupling; based on the traditional temperature analysis technology, the method is improved; on the one hand, the scheme constructs a concrete wind tunnel fluid heat transfer coupling model including a building model, a structural model and a fluid calculation model to realize the simulation calculation of the concrete cave wall temperature field, and realizes the multi-dimensional coupling of the building, the structural model and the fluid calculation; on the other hand, the scheme extracts key geometric feature nodes based on the building model to form a key topological structure, and generates secondary geometric feature nodes based on the key topological structure; at the same time, the key geometric feature nodes and the secondary geometric feature nodes are retained, and irrelevant or redundant nodes in the fluid heat transfer coupling model are eliminated, which greatly reduces the complexity of the original model, and at the same time, the accuracy of the fluid calculation is guaranteed by the key geometric feature nodes and the secondary geometric feature nodes; at the same time, the secondary geometric feature nodes generated by the scheme are not nodes of the plane dimension, but nodes of the space dimension, and finally the concrete cave wall temperature field obtained based on the simplified fluid heat transfer coupling model is a temperature field of the space dimension, which can meet the large wind tunnel building with multi-dimensional heat transfer characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings: Figure 1 It is a flow chart of the method for obtaining the temperature field of the concrete cavity wall based on fluid heat transfer coupling; Figure 2 Schematic diagram of the system structure for obtaining the temperature field of the concrete cave wall based on fluid heat transfer coupling. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0023] During the operation of the wind tunnel, the temperature field inside it changes with a large amplitude (far exceeding the ambient temperature) and a short change time, which significantly differs from the ambient temperature in the temperature change of the main structure. It is difficult to quantitatively determine the temperature distribution inside the building structure of a large wind tunnel under a short-term alternating temperature field. Traditional temperature analysis methods are mainly applicable to the single-dimensional heat transfer characteristics of temperature, and the resulting temperature distribution is low-dimensional, which cannot be applied to large wind tunnel buildings where the temperature has multi-dimensional heat transfer characteristics. In view of this, this solution provides the following embodiments to solve this technical problem.

[0024] Embodiment 1: This embodiment provides a method for obtaining the temperature field of a concrete cave wall based on fluid heat transfer coupling, such as Figure 1 As shown, including: Step 1: constructing a fluid heat transfer coupling model of a concrete wind tunnel, wherein the fluid heat transfer coupling model includes: an architectural model, a structural model and a fluid calculation model, and constructing a fluid calculation model of a concrete wind tunnel; In this step, a fluid heat transfer coupling model of a concrete wind tunnel is constructed, including the following methods: An architectural model of the concrete wind tunnel is constructed according to the shape parameters of the concrete wind tunnel and the shapes of the internal components, and a structural model of the concrete wind tunnel is constructed according to the material parameters and mechanical parameters; a fluid calculation model including a turbulence calculation model and control equations is constructed, and the control equations include: a mass conservation equation, a momentum conservation equation, and an energy conservation equation.

[0025] The method for constructing the building model comprises: The reinforced concrete structure area and the steel structure area of ​​the concrete wind tunnel are divided; the reinforced concrete structure area is modeled according to the actual thickness; the steel structure area is modeled according to the plane: the heat transfer resistance is converted according to the thickness of the steel material in the steel structure area, and a plane model of the steel structure area is constructed; the heat transfer resistance is input into the plane model to obtain the building model of the steel structure area; The internal components in the concrete wind tunnel are modeled according to the abstract structure: the adiabatic wall model is used as the architectural model of the guide vane; the internal cold source model is used as the architectural model of the heat exchanger.

[0026] To ensure the accuracy of the temperature field, this scheme constructs an architectural model of the concrete wind tunnel according to the actual construction drawing dimensions and restores the actual concrete wall thickness, so that the extracted key geometric feature nodes and secondary geometric feature nodes contain data in the thickness direction of the reinforced concrete structure area, increasing the accuracy of the temperature field in the simulation and taking into account the temperature changes of the concrete along the thickness of the tunnel wall in subsequent fluid calculations; this scheme constructs a model of the internal components through an abstract structural modeling method, restores the internal geometry of the concrete wind tunnel, and improves the accuracy of the gas velocity field in the concrete wind tunnel.

[0027] Step 2: extract key geometric feature nodes based on the building model to form a key topological structure, and generate secondary geometric feature nodes based on the key topological structure; this step specifically includes the following method: S21, dividing the building model into multiple sub-structure blocks according to the structure, obtaining boundary nodes of different surfaces of each sub-structure block, and using the remaining boundary nodes after removing duplicate boundary nodes as key geometric feature nodes, and connecting all the key geometric feature nodes to form a key topological structure; In this step, the building model is divided into a plurality of sub-structure blocks according to the structure, and the boundary nodes of different surfaces of each sub-structure block are obtained, including the method: S211, dividing the building model into a plurality of sub-structure blocks according to the structure: a concrete cave structure block, a steel structure grid structure block, a top plate steel beam structure block, a hanger structure block and a support structure block; S212, acquiring all surfaces of each substructure block, and determining all vertices connected to at least three surfaces as boundary nodes; S213, use the least squares method to fit the tangent plane for any point P and its neighboring points on each surface, project the point P and its neighboring points onto the tangent plane, and obtain a vector with the projection point of point P as the starting point and the projection point of the neighboring point as the end point; obtain the angle between each adjacent vector, and screen out the maximum angle δ between adjacent vectors max ; Compare the maximum angle δ between adjacent vectors max and the angle threshold, if the maximum angle δ max If the angle is greater than the angle threshold, the corresponding neighborhood point is determined as a boundary point.

[0028] S22, generate secondary geometric feature nodes based on each sub-structure block: set a first threshold E1, when the distance between two adjacent key geometric feature nodes is greater than the first threshold E1, determine m secondary geometric feature nodes between the two key geometric feature nodes; different sub-structure blocks have different architectural structures and functions, so different first thresholds E1 are set according to the situation when determining the secondary geometric feature nodes.

[0029] S23, taking m secondary geometric feature nodes and all key geometric feature nodes as target points, constructing candidate point sets for each target point: constructing a unit sphere with the target point as the sphere center, obtaining an inscribed z-hedron of the unit sphere, where z is an even number; dividing each face of the inscribed z-hedron into z / 2 triangles and radially projecting them onto the unit sphere surface; and constructing a candidate point set for the target point with the centroid of the z / 2 triangles; S24, calculating the characteristic value of each candidate point, and determining the secondary geometric characteristic node from each candidate point set based on the characteristic value. This step specifically includes the following method: The method of calculating the characteristic value of each candidate point and determining the secondary geometric characteristic node from each candidate point set based on the characteristic value includes: S241, calculate the eigenvalue K of candidate point i based on the following formula i : ; Among them, S i (*) represents the expected value of the midpoint * of the triangle where the candidate point i is located; p bi represents the first vertex in the triangle where the candidate point i is located; p ai represents the second vertex in the triangle where the candidate point i is located; p ci Represents the third vertex in the triangle where the candidate point i is located; S242, setting a feature threshold interval, and taking candidate points whose feature values ​​are within the feature threshold interval as secondary geometric feature nodes.

[0030] Step three: retain key geometric feature nodes and secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with the fluid calculation model; this step specifically includes the following methods: removing all nodes other than key geometric feature nodes and secondary geometric feature nodes in the building model; obtaining all required parameters in the calculation process of the fluid calculation model, and removing all parameters other than the required parameters in the structural model.

[0031] Step 4: Configure boundary conditions and obtain the temperature field of the concrete cavity wall based on the simplified fluid heat transfer coupling model; this step specifically includes the following methods: S41, meshing the simplified building model; this step specifically includes the following method: The reinforced concrete structure area of ​​the building model is divided into multiple cubic grids: the grid accuracy of the fluid inlet, fluid outlet, internal parts and areas for distinguishing different materials is set to the same as that of the reinforced concrete structure area; the number of cubic grids divided along the thickness direction of the reinforced concrete structure area is at least 6, and the side length of the cubic grid is 30mm~80mm; Divide the steel structure area of ​​the building model evenly into multiple squares.

[0032] S42, setting different working conditions and boundary conditions, and making the fluid heat transfer coupling model realize parameter coupling along the direction from the wind tunnel entrance to the wind tunnel exit, performing fluid calculation on each grid based on the k-epsilon turbulence equation and the fluid calculation model, and solving the control equation based on the finite volume method, and finally obtaining the airflow temperature distribution and velocity distribution on the concrete tunnel wall; Specifically, the CFD calculation boundary conditions are set according to the relevant parameters of the concrete wind tunnel operation, including the external wall temperature, fluid inlet velocity and temperature change input, and the time-varying cold and heat input of the cold and heat sources. According to the operating characteristics of the fan in the concrete wind tunnel, parameter coupling is achieved along the direction from the wind tunnel inlet to the wind tunnel outlet to achieve the continuity of energy and mass.

[0033] The mass conservation equation can be expressed as: the increase in mass in the microelement per unit time = the net mass flowing into the microelement in the same time interval; the momentum conservation equation can be expressed as: the rate of increase of fluid momentum in the microelement = the sum of various forces acting on the microelement; The energy conservation equation can be expressed as: the increase in energy in the microelement = the net heat flow entering the microelement + the work done on the microelement by volume force and surface force; the microelement is a cubic grid or a square grid.

[0034] S43, obtaining the temperature field of the concrete cave wall according to the air flow temperature distribution and velocity distribution.

[0035] Embodiment 2: This embodiment provides a concrete cave wall temperature field acquisition system based on fluid heat transfer coupling, which is used to implement the concrete cave wall temperature field acquisition method based on fluid heat transfer coupling described in Embodiment 1; Figure 2 As shown, the system comprises: A model building module is used to build a fluid heat transfer coupling model of a concrete wind tunnel, wherein the fluid heat transfer coupling model includes: an architectural model, a structural model and a fluid calculation model, and a fluid calculation model of a concrete wind tunnel is built; A node extraction module, used to extract key geometric feature nodes based on the building model to form a key topological structure, and generate secondary geometric feature nodes based on the key topological structure; A simplification module, used to retain key geometric feature nodes and secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with a fluid calculation model; The output module is used to configure boundary conditions and obtain the temperature field of the concrete cavity wall based on the simplified fluid heat transfer coupling model.

[0036] Through the concrete cave wall temperature field acquisition system based on fluid heat transfer coupling of this embodiment, seamless data transmission can be achieved between multiple professional fields such as construction engineering, fluid mechanics and material science, significantly improving the collaborative efficiency of wind tunnel analysis; automatic iterative calculations can be performed based on digital parameter inputs, such as adjusting the cave wall thickness and adjusting the cold source parameters, and the geometric model can be quickly iterated through the model component module, and the heat transfer analysis model can be performed through the node extraction module and the simplification module, and the calculation results are generated based on the output module, and the data format that is easy to use for downstream design can be quickly obtained through the output module.

[0037] Embodiment 3: This embodiment provides a computer-readable medium on which a computer program is stored. The computer program is executed by a processor to implement the method for obtaining the temperature field of a concrete cave wall based on fluid heat transfer coupling as described in Embodiment 1. Specifically, the following steps are performed: Step 1: constructing a fluid heat transfer coupling model of a concrete wind tunnel, wherein the fluid heat transfer coupling model includes: an architectural model, a structural model and a fluid calculation model, and constructing a fluid calculation model of a concrete wind tunnel; Step 2: extracting key geometric feature nodes based on the building model to form a key topological structure, and generating secondary geometric feature nodes based on the key topological structure; Step 3: retain key geometric feature nodes and secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with the fluid calculation model; Step 4: Configure boundary conditions and obtain the temperature field of the concrete cavity wall based on the simplified fluid heat transfer coupling model. This step specifically includes: S41, based on CFD software, the simplified building model is meshed; the mesh near the boundary layer is encrypted, and the mesh density is reasonably planned to ensure calculation accuracy and efficiency.

[0038] S42, setting different working conditions and boundary conditions, and making the fluid heat transfer coupling model realize parameter coupling along the direction from the wind tunnel entrance to the wind tunnel exit, performing fluid calculation on each grid based on the k-epsilon turbulence equation and the fluid calculation model, and solving the control equation based on the finite volume method, and finally obtaining the airflow temperature distribution and velocity distribution of the fluid on the surface of the concrete tunnel wall; S43, obtaining the temperature field of the concrete cave wall according to the air flow temperature distribution and velocity distribution.

[0039] This embodiment is based on the idea of ​​parametric programming. Through the parametric program built on the GRASSHOPPER platform, the automatic identification of wind tunnel building models, the extraction of key geometric feature nodes, the generation of topological structures, and the precise conversion of geometric models are realized to solve the data barrier problem existing in the transmission of multi-professional models. In the specific operation, the parametric program first identifies the geometric features of the input wind tunnel building model and extracts the key geometric nodes reflecting the core structure of the model. These nodes form the basis for generating iterative topological structures. According to the topological structure, secondary geometric feature nodes are generated layer by layer, and irrelevant or redundant nodes in the model are eliminated. On this basis, the parametric program can intelligently simplify the building model and the structural model according to the requirements of fluid mechanics calculations, greatly reducing the complexity of the model while ensuring the accuracy of the calculation. The conversion process of the fluid heat transfer coupling model not only improves the efficiency of cross-disciplinary data transmission, but also provides an efficient and accurate geometric basis for subsequent fluid analysis. During the conversion process of the fluid heat transfer coupling model, the database embedded in the program can automatically identify the material properties in the structural model and quantify them; for example, the parameterization program can assign physical parameter values ​​such as density, specific heat capacity, and heat transfer coefficient according to the identified building and structural materials, and complete the partial automatic assignment of boundary conditions required for fluid calculation; it not only reduces the complexity of manual intervention, but also effectively reduces the errors that may be caused by manual operation, and further improves the efficiency and reliability of fluid analysis. Based on digital iterative calculations, the parameterization program can support higher-level coupling analysis on the basis of completing the geometric model and physical parameter transfer. By realizing multi-dimensional comprehensive simulation of wind tunnel structure, fluid flow and heat transfer characteristics, it provides important technical support for the rational design of wind tunnels. This analysis method enables the design of wind tunnels to shift from single-dimensional static modeling to dynamic, multi-dimensional coupled comprehensive evaluation, which not only significantly improves the efficiency of wind tunnel fluid calculations, but also provides a reliable basis for optimizing building forms and improving design rationality. This solution method realizes seamless data transmission between multiple professional fields such as construction engineering, fluid mechanics and materials science, significantly improving the collaborative efficiency of wind tunnel analysis.

[0040] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling, characterized in that: include: Constructing a fluid heat transfer coupling model of a concrete wind tunnel, wherein the fluid heat transfer coupling model includes: an architectural model, a structural model and a fluid calculation model, and constructing a fluid calculation model of a concrete wind tunnel; Extracting key geometric feature nodes based on the building model to form a key topological structure, and generating secondary geometric feature nodes based on the key topological structure; Retaining key geometric feature nodes and secondary geometric feature nodes, and simplifying the fluid heat transfer coupling model in combination with a fluid calculation model; The boundary conditions are configured, and the temperature field of the concrete cavity wall is obtained based on the simplified fluid heat transfer coupling model.

2. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 1 is characterized in that: The method of constructing a fluid heat transfer coupling model for a concrete wind tunnel includes: An architectural model of the concrete wind tunnel is constructed according to the shape parameters of the concrete wind tunnel and the shapes of the internal components, and a structural model of the concrete wind tunnel is constructed according to the material parameters and mechanical parameters; a fluid calculation model including a turbulence calculation model and control equations is constructed, and the control equations include: a mass conservation equation, a momentum conservation equation, and an energy conservation equation.

3. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 2 is characterized in that: The method for constructing the building model comprises: The reinforced concrete structure area and the steel structure area of ​​the concrete wind tunnel are divided; the reinforced concrete structure area is modeled according to the actual thickness; the steel structure area is modeled according to the plane: the heat transfer resistance is converted according to the thickness of the steel material in the steel structure area, and a plane model of the steel structure area is constructed; the heat transfer resistance is input into the plane model to obtain the building model of the steel structure area; The internal components in the concrete wind tunnel are modeled according to the abstract structure: the adiabatic wall model is used as the architectural model of the guide vane; the internal cold source model is used as the architectural model of the heat exchanger.

4. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 3 is characterized in that: Extracting key geometric feature nodes based on the building model to form a key topological structure, and generating secondary geometric feature nodes based on the key topological structure; Included methods: Dividing the building model into multiple sub-structure blocks according to the structure, obtaining boundary nodes of different surfaces of each sub-structure block, and using the remaining boundary nodes after removing duplicate boundary nodes as key geometric feature nodes, connecting all the key geometric feature nodes to form a key topological structure; Generate secondary geometric feature nodes in units of each substructure block: set a first threshold E1, and when the distance between two adjacent key geometric feature nodes is greater than the first threshold E1, determine m secondary geometric feature nodes between the two key geometric feature nodes; Take m secondary geometric feature nodes and all key geometric feature nodes as target points, and construct candidate point sets for each target point: construct a unit sphere with the target point as the sphere center, obtain the inscribed z-hedron of the unit sphere, where z is an even number; divide each face of the inscribed z-hedron into z / 2 triangles and project them radially onto the unit sphere surface; use the centroid of the z / 2 triangles to form the candidate point set of the target point; The eigenvalue of each candidate point is calculated, and the secondary geometric feature nodes are determined from each candidate point set based on the eigenvalue.

5. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 4 is characterized in that: The method of dividing the building model into a plurality of sub-structure blocks according to the structure and obtaining boundary nodes of different surfaces of each sub-structure block includes: The building model is divided into multiple sub-structure blocks according to the structure: concrete cave structure block, steel structure grid structure block, top plate steel beam structure block, hanger structure block and support structure block; Obtain all surfaces of each substructure block, and determine all vertices connected to at least three surfaces as boundary nodes; The tangent plane is fitted for any point P and its neighboring points on each surface using the least squares method. Point P and its neighboring points are projected onto the tangent plane, and a vector is obtained with the projection point of point P as the starting point and the projection point of the neighboring point as the end point. The angle between each adjacent vector is obtained, and the maximum angle δ between adjacent vectors is screened out. max ; Compare the maximum angle δ between adjacent vectors max and the angle threshold, if the maximum angle δ max If the angle is greater than the angle threshold, the corresponding neighborhood point is determined as a boundary point.

6. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 4 is characterized in that: The method of calculating the characteristic value of each candidate point and determining the secondary geometric characteristic node from each candidate point set based on the characteristic value includes: The eigenvalue K of candidate point i is calculated based on the following formula i : ； Among them, S i (*) represents the expected value of the midpoint * of the triangle where the candidate point i is located; p bi represents the first vertex in the triangle where the candidate point i is located; p ai represents the second vertex in the triangle where the candidate point i is located; p ci Represents the third vertex in the triangle where the candidate point i is located; Set the feature threshold interval and select the candidate points whose feature values ​​are within the feature threshold interval as secondary geometric feature nodes.

7. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 3 is characterized in that: The key geometric feature nodes and the secondary geometric feature nodes are retained, and the fluid heat transfer coupling model is simplified in combination with the fluid calculation model; The method includes: removing all nodes except key geometric feature nodes and secondary geometric feature nodes in the building model; obtaining all required parameters in the calculation process of the fluid calculation model, and removing all parameters except the required parameters in the structural model.

8. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 7 is characterized in that: The configuration boundary conditions are used to obtain the concrete cavity wall temperature field based on a simplified fluid heat transfer coupling model; including: method: Meshing the simplified building model; Different working conditions and boundary conditions are set, and the fluid heat transfer coupling model is parameter-coupled along the direction from the wind tunnel entrance to the wind tunnel exit. The fluid calculation is performed on each grid based on the k-epsilon turbulence equation and the fluid calculation model, and the control equation is solved based on the finite volume method. Finally, the airflow temperature distribution and velocity distribution of the fluid on the surface of the concrete tunnel wall are obtained. The temperature field of the concrete cave wall is obtained based on the air flow temperature distribution and velocity distribution.

9. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 8 is characterized in that: The simplified building model is meshed; including a method: The reinforced concrete structure area of ​​the building model is divided into multiple cubic grids: for the fluid inlet, fluid outlet, internal parts and areas distinguishing different materials, the same grid accuracy as the reinforced concrete structure area is set; The number of cubic grids divided along the thickness direction of the reinforced concrete structure area is at least 6, and the side length of the cubic grid is 30mm~80mm; Divide the steel structure area of ​​the building model evenly into multiple squares.

10. The concrete cave wall temperature field acquisition system based on fluid heat transfer coupling is characterized by: A method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to any one of claims 1 to 9; the system comprises: A model building module is used to build a fluid heat transfer coupling model of a concrete wind tunnel, wherein the fluid heat transfer coupling model includes: an architectural model, a structural model and a fluid calculation model, and a fluid calculation model of a concrete wind tunnel is built; A node extraction module, used to extract key geometric feature nodes based on the building model to form a key topological structure, and generate secondary geometric feature nodes based on the key topological structure; A simplification module, used to retain key geometric feature nodes and secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with a fluid calculation model; The output module is used to configure boundary conditions and obtain the temperature field of the concrete cavity wall based on the simplified fluid heat transfer coupling model.

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