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

Abstract

The present invention discloses a method and system for acquiring a temperature field of a concrete cave wall based on fluid heat transfer coupling. The method relates to the technical field of wind tunnel building design, and constructs a concrete wind tunnel fluid heat transfer coupling model including a building model, a structural model and a fluid calculation model to realize simulation calculation of the concrete cave wall temperature field, and realize multi-dimensional coupling of building, structural and fluid calculation. 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. At the same time, irrelevant or redundant nodes in the fluid heat transfer coupling model are eliminated, so as to greatly reduce the complexity of the model and ensure the accuracy of fluid calculation. The secondary geometric feature nodes generated from the spatial dimension in this scheme make the finally obtained concrete cave wall temperature field a temperature field of the spatial dimension, which can meet the requirements of large-scale wind tunnel buildings with multi-dimensional heat transfer characteristics.

Description

Technical Field

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

[0002] For a large wind tunnel, its tunnel wall is usually the building side wall. Functionally, it is both an experimental device and a building structure. In building structure design, various safety factors and functional requirements in conventional design need to be considered, and at the same time, the process requirements and load requirements of the wind tunnel equipment need to be met. The temperature effect is an important control factor that cannot be ignored. During the operation of the wind tunnel, the fan generates a large amount of heat. The heat acts on the tunnel wall along with the airflow, causing the temperature at the position where the tunnel wall is in direct contact with the airflow to rise rapidly, and transferring heat to the outside of the tunnel wall through heat conduction, generating a gradient temperature difference along the tunnel wall outward; after the fan stops working, the air inside the tunnel will gradually cool down; when the wind tunnel is working, the temperature inside the tunnel rises, and after stopping working, the temperature inside the tunnel drops, repeating in cycles to form an alternating temperature field.

[0003] There is no relatively mature and unified engineering treatment method for how to determine the temperature effect in a large wind tunnel building, how to establish a structural analysis model that can reasonably consider the gradient or even non-linear temperature effect, and how to carry out 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 throughout the process from the fan outlet to the fan inlet. The main reason is that at the initial stage of the experiment, the temperature of the enclosure structure is relatively low, which can absorb the heat in the high-temperature air, causing the temperature of the airflow to decrease and the temperature of the enclosure structure to increase. As the heat absorbed by the enclosure structure increases, 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 operation time increases, the cooling effect of the air by the enclosure structure becomes worse and worse.

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

[0006] As can be seen from the above analysis, during the operation of the wind tunnel, the internal temperature field changes significantly (far exceeding the ambient temperature) and the change time is short. Therefore, the influence of the temperature change on the main structure is significantly different from the ambient temperature. It is difficult to quantitatively determine the temperature distribution inside the large wind tunnel building structure under the short-term alternating temperature field. The heat transfer between the airflow and the tunnel body is coupled with multiple factors and has multi-dimensional characteristics in space and time, and cannot be analyzed by simple analytical methods. Summary of the Invention

[0007] The technical problem to be solved by the present invention is that traditional temperature analysis methods are mainly applicable to the single-dimensional heat transfer characteristics of temperature, and the obtained temperature distribution is of low dimension and cannot be applied to the scenario where the temperature in a large wind tunnel building has multi-dimensional heat transfer characteristics. The purpose of the present invention is to provide a method for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling, and to improve the method on the basis of traditional temperature analysis technology. On the one hand, this solution 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 temperature field of the concrete tunnel wall, and realizes the multi-dimensional coupling of building, structural type and fluid calculation, and solves the data barrier problem existing in the transfer of different models. On the other hand, this solution extracts key geometric feature nodes from the building model to form a key topological structure, and generates secondary geometric feature nodes on the basis of the key topological structure; at the same time, both 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 removed, greatly reducing the complexity of the original model, and at the same time ensuring the accuracy of fluid calculation through the key geometric feature nodes and the secondary geometric feature nodes; at the same time, the secondary geometric feature nodes generated by this solution are not planar-dimensional nodes, but spatial-dimensional nodes. Finally, the temperature field of the concrete tunnel wall obtained based on the simplified fluid heat transfer coupling model is a spatial-dimensional temperature field, which can meet the large wind tunnel building with multi-dimensional heat transfer characteristics.

[0008] The present invention is realized by the following technical solutions:

[0009] This solution provides a method for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling, including:

[0010] Construct a fluid heat transfer coupling model of the concrete wind tunnel, and the fluid heat transfer coupling model includes: a building model, a structural model and a fluid calculation model, and construct a fluid calculation model of the concrete wind tunnel;

[0011] Extract key geometric feature nodes from the building model to form a key topological structure, and generate secondary geometric feature nodes on the basis of the key topological structure;

[0012] Retain the key geometric feature nodes and secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with the fluid calculation model;

[0013] Configure the boundary conditions, and obtain the concrete tunnel wall temperature field based on the simplified fluid heat transfer coupling model.

[0014] The working principle of this solution: This solution improves the method on the basis of traditional temperature analysis technology; on the one hand, this solution 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 tunnel wall temperature field, realizes the multi-dimensional coupling of architecture, structure type and fluid calculation, and solves the data barrier problem existing in the transfer of different models; on the other hand, this solution extracts key geometric feature nodes from the building model to form a key topological structure, and generates secondary geometric feature nodes on the basis of the key topological structure; at the same time, retain the key geometric feature nodes and secondary geometric feature nodes, eliminate irrelevant or redundant nodes in the fluid heat transfer coupling model, greatly reduce the complexity of the original model, and at the same time ensure the accuracy of fluid calculation through the key geometric feature nodes and secondary geometric feature nodes; at the same time, the secondary geometric feature nodes generated by this solution are not planar dimension nodes, but spatial dimension nodes. Finally, the concrete tunnel wall temperature field obtained based on the simplified fluid heat transfer coupling model is a spatial dimension temperature field, which can meet the large wind tunnel buildings with multi-dimensional heat transfer characteristics.

[0015] The further optimized solution is that the method for constructing the fluid heat transfer coupling model of the concrete wind tunnel includes:

[0016] Construct a building model of the concrete wind tunnel according to the shape parameters of the concrete wind tunnel and the shape of the internal components, and construct a structural model of the concrete wind tunnel according to the material parameters and mechanical parameters; construct a fluid calculation model including a turbulence calculation model and control equations, and the control equations include: mass conservation equation, momentum conservation equation and energy conservation equation.

[0017] The further optimized solution is that the construction method of the building model includes:

[0018] Divide the reinforced concrete structure area and the steel structure area of the concrete wind tunnel; model the reinforced concrete structure area according to the actual thickness; model the steel structure area in a plane: calculate the heat transfer thermal resistance according to the thickness of the steel material in the steel structure area, and construct a plane model of the steel structure area; input the heat transfer thermal resistance into the plane model to obtain the building model of the steel structure area;

[0019] Model the internal components in the concrete wind tunnel according to the abstract structure: use the adiabatic wall model as the building model of the guide vane; use the internal cold source model as the building model of the heat exchanger.

[0020] A further optimization solution is that the key geometric feature nodes are extracted from the building model to form a key topological structure, and secondary geometric feature nodes are generated on the basis of the key topological structure; the method includes:

[0021] Divide the building model into multiple sub - structure blocks according to the structure, obtain the boundary nodes of different surfaces of each sub - structure block, and use the remaining boundary nodes after removing duplicate boundary nodes as key geometric feature nodes, and connect all key geometric feature nodes to form a key topological structure;

[0022] Generate secondary geometric feature nodes with each sub - structure block as a unit: set the first threshold E 1 , when the distance between two adjacent key geometric feature nodes is greater than the first threshold E 1 , determine m secondary geometric feature nodes between the two key geometric feature nodes; the building structures and functions of different sub - structure blocks are different, so different first thresholds E are set according to the situation when determining secondary geometric feature nodes 1 .

[0023] Take m secondary geometric feature nodes and all key geometric feature nodes as target points, and construct an alternative point set for each target point: construct a unit sphere with the target point as the center of the sphere, obtain the inscribed z - polyhedron of the unit sphere, where z is an even number; divide each face of the inscribed z - polyhedron into z / 2 triangles and project them radially onto the unit sphere surface; use the centroids of the z / 2 triangles to form the alternative point set of the target point;

[0024] Calculate the eigenvalue of each alternative point, and determine the secondary geometric feature nodes from each alternative point set based on the eigenvalue.

[0025] A further optimization solution is that the method of dividing the building model into multiple sub - structure blocks according to the structure and obtaining the boundary nodes of different surfaces of each sub - structure block includes:

[0026] Divide the building model into multiple sub - structure blocks according to the structure: concrete cavity structure block, steel structure grid structure block, roof steel beam structure block, hanger structure block and support structure block;

[0027] Obtain all surfaces of each sub - structure block, and determine all vertices connected to at least 3 surfaces as boundary nodes;

[0028] For any point P and its neighborhood points on each surface, perform tangent plane fitting using the least - squares method, project point P and its neighborhood 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 neighborhood point as the ending point; obtain the included angle between each adjacent vector, and screen out the maximum included angle δ max ; compare the size of the maximum included angle δ max between adjacent vectors with the angle threshold. If the maximum included angle δ maxIf it is greater than the angle threshold, the corresponding neighborhood points are determined as boundary points.

[0029] A further optimization solution is that the eigenvalues of each alternative point are calculated, and the secondary geometric feature nodes are determined from each set of alternative points, including the method:

[0030] Calculate the eigenvalue K of alternative point i based on the following formula i :

[0031] ;

[0032] where S i (*) represents the expected value of the midpoint * of the triangle where alternative point i is located; p bi represents the first vertex in the triangle where alternative point i is located; p ai represents the second vertex in the triangle where alternative point i is located; p ci represents the third vertex in the triangle where alternative point i is located;

[0033] Set the eigenvalue threshold interval, and use the alternative points whose eigenvalues are within the eigenvalue threshold interval as secondary geometric feature nodes.

[0034] A further optimization solution is that the key geometric feature nodes and secondary geometric feature nodes are retained, and the fluid heat transfer coupling model is simplified in combination with the fluid calculation model; including the method: all nodes other than the key geometric feature nodes and secondary geometric feature nodes are removed in the building model; all required parameters during the calculation process of the fluid calculation model are obtained, and all parameters other than the required parameters are removed in the structural model.

[0035] A further optimization solution is that the boundary conditions are configured, and the concrete cavity wall temperature field is obtained based on the simplified fluid heat transfer coupling model; including the method:

[0036] Perform mesh division on the simplified building model;

[0037] Set different working conditions and boundary conditions, and realize parameter coupling of the fluid heat transfer coupling model from the wind tunnel inlet to the wind tunnel outlet direction. Perform fluid calculation on each grid based on the k-epsilon turbulence equation and the fluid calculation model, and solve the control equation based on the finite volume method. Finally, obtain the air flow temperature distribution and velocity distribution of the fluid on the concrete cavity wall surface.

[0038] Obtain the concrete cavity wall temperature field according to the air flow temperature distribution and velocity distribution.

[0039] A further optimization solution is that the mesh division of the simplified building model is performed; including the method:

[0040] Divide the reinforced concrete structure area of the building model into multiple cubic grids: For the fluid inlet, fluid outlet, internal components, and areas for differentiating different materials, set the same grid accuracy 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 30 mm to 80 mm;

[0041] Divide the steel structure area of the building model evenly into multiple squares.

[0042] This solution also provides a system for obtaining the concrete cavity wall temperature field based on fluid heat transfer coupling, which is used to implement the method for obtaining the concrete cavity wall temperature field based on fluid heat transfer coupling described above; The system includes:

[0043] A model construction module, which is used to construct a fluid heat transfer coupling model of the concrete wind tunnel. The fluid heat transfer coupling model includes: a building model, a structural model, and a fluid calculation model, and constructs a fluid calculation model of the concrete wind tunnel;

[0044] A node extraction module, which is used to extract key geometric feature nodes from the building model to form a key topological structure, and generate secondary geometric feature nodes based on the key topological structure;

[0045] A simplification module, which is used to retain the key geometric feature nodes and secondary geometric feature nodes, and simplify the fluid heat transfer coupling model in combination with the fluid calculation model;

[0046] An output module, which is used to configure boundary conditions and obtain the concrete cavity wall temperature field based on the simplified fluid heat transfer coupling model.

[0047] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0048] The method for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling provided by the present invention improves the method on the basis of traditional temperature analysis techniques. On the one hand, this solution 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 temperature field of the concrete tunnel wall, achieving multi-dimensional coupling of building, structure type, and fluid calculation. On the other hand, this solution extracts key geometric feature nodes from 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, both 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 removed, greatly reducing the complexity of the original model. At the same time, the accuracy of fluid calculation is ensured through the key geometric feature nodes and the secondary geometric feature nodes. At the same time, the secondary geometric feature nodes generated by this solution are not planar-dimensional nodes, but spatial-dimensional nodes. Finally, the temperature field of the concrete tunnel wall obtained based on the simplified fluid heat transfer coupling model is a spatial-dimensional temperature field, which can meet the requirements of large wind tunnel buildings with multi-dimensional heat transfer characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts. In the drawings:

[0050] Figure 1 It is a schematic flow chart of the method for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling;

[0051] Figure 2 It is a schematic structural diagram of the system for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] In order to make the purpose, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below in combination with the embodiments and the drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not used to limit the present invention.

[0053] During the operation of the wind tunnel, the internal temperature field changes significantly (far exceeding the ambient temperature) and the change time is short. Therefore, the influence of the temperature change on the main structure is significantly different from the ambient temperature. It is difficult to quantitatively determine the temperature distribution inside the large wind tunnel building structure under the short-term alternating temperature field. The traditional temperature analysis method is mainly applicable to the single-dimensional heat transfer characteristics of temperature, and the obtained temperature distribution is of low dimension, which cannot be applied to the scenario where the temperature in the large wind tunnel building has multi-dimensional heat transfer characteristics. In view of this, the following embodiments are provided in this solution to solve this technical problem.

[0054] Embodiment 1: This embodiment provides a method for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling, as Figure 1 shown, including:

[0055] Step 1: Construct a fluid heat transfer coupling model for the concrete wind tunnel. The fluid heat transfer coupling model includes: a building model, a structural model, and a fluid calculation model, and construct the fluid calculation model of the concrete wind tunnel;

[0056] In this step, constructing the fluid heat transfer coupling model of the concrete wind tunnel includes the method:

[0057] Construct the building model of the concrete wind tunnel according to the shape parameters of the concrete wind tunnel and the shape of the internal components, and construct the structural model of the concrete wind tunnel according to the material parameters and mechanical parameters; construct a fluid calculation model including a turbulence calculation model and control equations. The control equations include: a mass conservation equation, a momentum conservation equation, and an energy conservation equation.

[0058] The construction method of the building model includes:

[0059] Divide the reinforced concrete structure area and the steel structure area of the concrete wind tunnel; model the reinforced concrete structure area according to the actual thickness; model the steel structure area in a plane: calculate the heat transfer thermal resistance according to the thickness of the steel material in the steel structure area, and construct a plane model of the steel structure area; input the heat transfer thermal resistance into the plane model to obtain the building model of the steel structure area;

[0060] Model the internal components in the concrete wind tunnel according to the abstract structure: use the adiabatic wall model as the building model of the guide vane; use the internal cold source model as the building model of the heat exchanger.

[0061] To ensure the accuracy of the temperature field, in this solution, a building model of the concrete wind tunnel is constructed according to the dimensions of the actual construction drawings, and the actual concrete wall thickness is restored, so that the data in the thickness direction of the reinforced concrete structure area is included in the extracted key geometric feature nodes and secondary geometric feature nodes, increasing the accuracy of the temperature field in the simulation, and realizing the consideration of the temperature change of the concrete along the thickness direction of the tunnel wall during subsequent fluid calculations; in this solution, the model of the internal components is constructed by the abstract structure modeling method, and the internal geometry of the concrete wind tunnel is restored to improve the accuracy of the gas velocity field in the concrete wind tunnel.

[0062] Step 2: Extract key geometric feature nodes from 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 method:

[0063] S21, divide the building model into multiple sub-structure blocks according to the structure, obtain the boundary nodes of different surfaces of each sub-structure block, and use the remaining boundary nodes after removing the duplicate boundary nodes as the key geometric feature nodes, and connect all the key geometric feature nodes to form a key topological structure;

[0064] In this step, dividing the building model into multiple sub-structure blocks according to the structure and obtaining the boundary nodes of different surfaces of each sub-structure block includes the method:

[0065] S211, divide the building model into multiple sub-structure blocks according to the structure: concrete tunnel body structure block, steel structure grid structure block, roof steel beam structure block, suspension rod structure block and support structure block;

[0066] S212, obtain all the surfaces of each sub-structure block, and determine all the vertices connected to at least 3 surfaces as boundary nodes;

[0067] S213, perform tangent plane fitting on any point P and its neighborhood points on each surface by the least square method, project point P and its neighborhood 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 neighborhood points as the end point; obtain the included angle between each adjacent vector, and screen out the maximum included angle δ between adjacent vectors max ; Compare the maximum included angle δ between adjacent vectors max with the angle threshold. If the maximum included angle δ max is greater than the angle threshold, then determine the corresponding neighborhood point as a boundary point.

[0068] S22, generate secondary geometric feature nodes for each sub-structure block: set the first threshold E 1 , when the distance between two adjacent key geometric feature nodes is greater than the first threshold E 1When, m secondary geometric feature nodes are determined between two key geometric feature nodes; the building structures and functions of different sub-structure blocks are different, so different first thresholds E are set according to the situation when determining the secondary geometric feature nodes 1 。

[0069] S23, taking the m secondary geometric feature nodes and all key geometric feature nodes as target points, constructing an alternative point set for each target point: constructing a unit sphere with the target point as the center of the sphere, obtaining the inscribed z-sided polyhedron of the unit sphere, where z is an even number; dividing each face of the inscribed z-sided polyhedron into z / 2 triangles and radially projecting them onto the unit sphere surface; forming an alternative point set for the target point with the centroids of the z / 2 triangles

[0070] S24, calculating the characteristic values of each alternative point, and determining the secondary geometric feature nodes from each alternative point set based on the characteristic values. This step specifically includes the method

[0071] The calculating the characteristic values of each alternative point, and determining the secondary geometric feature nodes from each alternative point set based on the characteristic values, includes the method

[0072] S241, calculating the characteristic value K of alternative point i based on the following formula i :

[0073] ;

[0074] where, S i (*)represents the expected value of the midpoint * of the triangle where alternative point i is located; p bi represents the first vertex in the triangle where alternative point i is located; p ai represents the second vertex in the triangle where alternative point i is located; p ci represents the third vertex in the triangle where alternative point i is located

[0075] S242, setting a characteristic threshold interval, and taking the alternative points whose characteristic values are within the characteristic threshold interval as secondary geometric feature nodes

[0076] Step three: Retaining the key geometric feature nodes and secondary geometric feature nodes, and simplifying the fluid heat transfer coupling model in combination with the fluid calculation model; this step specifically includes the method: removing all nodes other than the key geometric feature nodes and secondary geometric feature nodes in the building model; obtaining all required parameters during the calculation process of the fluid calculation model, and removing all parameters other than the required parameters in the structural model

[0077] Step four: Configuring boundary conditions, and obtaining the concrete hole wall temperature field based on the simplified fluid heat transfer coupling model; this step specifically includes the method

[0078] S41, performing mesh division on the simplified building model; this step specifically includes the method

[0079] Divide the reinforced concrete structure area of the building model into multiple cubic grids: For the fluid inlet, fluid outlet, internal components, and areas for differentiating different materials, set the same grid accuracy 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 30 mm to 80 mm;

[0080] Evenly divide the steel structure area of the building model into multiple squares.

[0081] S42, Set different working conditions and boundary conditions, and enable the fluid heat transfer coupling model to achieve parameter coupling along the direction from the wind tunnel inlet to the wind tunnel outlet. Conduct fluid calculations on each grid based on the k-epsilon turbulence equation and the fluid calculation model, and solve the control equation based on the finite volume method. Finally, obtain the air flow temperature distribution and velocity distribution of the concrete tunnel wall;

[0082] Specifically, set the CFD calculation boundary conditions according to the relevant parameters of the concrete wind tunnel operation, such as setting the outer wall surface temperature, fluid inlet velocity and temperature change input, cold and heat input of the cold and heat sources changing with time, etc. According to the operation characteristics of the fans in the concrete wind tunnel, achieve parameter coupling along the direction from the wind tunnel inlet to the wind tunnel outlet, and achieve the continuity of energy and mass.

[0083] 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 during the same time interval; The momentum conservation equation can be expressed as: The increase rate of the fluid momentum in the microelement = the sum of various forces acting on the microelement;

[0084] The energy conservation equation can be expressed as: The increase in internal energy in the microelement = the net heat flux entering the microelement + the work done by the body force and surface force on the microelement; The microelement is a cubic grid or a square.

[0085] S43, Obtain the temperature field of the concrete tunnel wall according to the air flow temperature distribution and velocity distribution.

[0086] Embodiment 2: This embodiment provides a system for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling, which is used to implement the method for obtaining the temperature field of a concrete tunnel wall based on fluid heat transfer coupling described in Embodiment 1; As Figure 2 shown, the system includes:

[0087] A model construction module, which is used to construct a fluid heat transfer coupling model of the concrete wind tunnel. The fluid heat transfer coupling model includes: a building model, a structural model, and a fluid calculation model, and constructs a fluid calculation model of the concrete wind tunnel;

[0088] A node extraction module, configured to extract key geometric feature nodes based on the building model to form a key topological structure, and generate secondary geometric feature nodes on the basis of the key topological structure;

[0089] A simplification module, configured 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;

[0090] An output module, configured to configure boundary conditions and obtain the concrete tunnel wall temperature field based on the simplified fluid heat transfer coupling model.

[0091] Through the concrete tunnel wall temperature field acquisition system based on fluid heat transfer coupling in this embodiment, seamless data transfer can be achieved among multiple professional fields such as construction engineering, fluid mechanics, and materials science, significantly improving the collaborative efficiency of wind tunnel analysis; automatic iterative calculations can be performed based on digital parameter inputs. For example, after adjusting the tunnel wall thickness and cold source parameters, rapid iteration of the geometric model can be achieved through the model component module, and the heat transfer analysis model can be performed through the node extraction module and the simplification module. The calculation results are generated based on the output module, and data formats that are easy to use for downstream design can be quickly obtained through the output module.

[0092] Embodiment 3: This embodiment provides a computer-readable medium, on which a computer program is stored. When the computer program is executed by a processor, the method for obtaining the concrete tunnel wall temperature field based on fluid heat transfer coupling as described in Embodiment 1 can be implemented; specifically, the following steps are performed:

[0093] Step 1: Construct a fluid heat transfer coupling model of a concrete wind tunnel, where the fluid heat transfer coupling model includes: a building model, a structural model, and a fluid calculation model, and construct a fluid calculation model of the concrete wind tunnel;

[0094] Step 2: Extract key geometric feature nodes based on the building model to form a key topological structure, and generate secondary geometric feature nodes on the basis of the key topological structure;

[0095] Step 3: 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;

[0096] Step 4: Configure boundary conditions and obtain the concrete tunnel wall temperature field based on the simplified fluid heat transfer coupling model. This step specifically includes:

[0097] S41, perform mesh division on the simplified building model based on CFD software; encrypt the mesh near the boundary layer, and reasonably plan the mesh density to ensure calculation accuracy and efficiency.

[0098] S42. Set different working conditions and boundary conditions, and realize parameter coupling for the fluid heat transfer coupling model along the direction from the wind tunnel inlet to the wind tunnel outlet. Perform fluid calculations on each grid based on the k-epsilon turbulence equation and the fluid calculation model, and solve the control equation based on the finite volume method. Finally, obtain the air flow temperature distribution and velocity distribution of the fluid on the concrete tunnel wall surface;

[0099] S43. Obtain the temperature field of the concrete tunnel wall according to the air flow temperature distribution and velocity distribution.

[0100] Based on the idea of parametric programming, this embodiment realizes the automatic recognition of the wind tunnel building model, the extraction of key geometric feature nodes, the generation of topological structures, and the accurate conversion of geometric models through a parametric program built on the GRASSHOPPER platform, solving the data barrier problem existing in the transfer of multi-disciplinary models; In specific operations, the parametric program first performs geometric feature recognition on the input wind tunnel building model and extracts 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 removed. 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 calculations. The conversion process of the fluid heat transfer coupling model not only improves the cross-disciplinary data transfer efficiency 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 embedded database in the program can automatically identify the material properties in the structural model and quantify them; for example, the parametric program can assign physical property parameter values such as density, specific heat capacity, and heat transfer coefficient according to the identified building and structural materials, completing partial automatic assignment of the boundary conditions required for fluid calculations; This not only reduces the complexity of manual intervention but also effectively reduces the errors that may be brought by manual operations, further improving the efficiency and reliability of fluid analysis. Based on digital iterative calculations, the parametric program can support higher-level coupling analysis on the basis of completing the transfer of geometric models and physical property parameters. By realizing multi-dimensional comprehensive simulation of wind tunnel structures, fluid flow, and heat transfer characteristics, it provides important technical support for the reasonable design of wind tunnels. Such an analysis method enables the design of wind tunnels to shift from single-dimensional static modeling to dynamic and multi-dimensional coupled comprehensive evaluation, not only significantly improving the efficiency of wind tunnel fluid calculations but also providing a reliable basis for optimizing the building form and improving the design rationality; The method of this solution realizes seamless data transfer among multiple professional fields such as construction engineering, fluid mechanics, and materials science, significantly improving the collaborative efficiency of wind tunnel analysis.

[0101] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope 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, the fluid heat transfer coupling model includes: a building model, a structural model and a fluid calculation model, and constructing a fluid calculation model of the concrete wind tunnel; the method of constructing the fluid heat transfer coupling model of the concrete wind tunnel includes: Constructing an architectural model of the concrete wind tunnel according to the concrete wind tunnel shape parameters and the shapes of the internal components, and constructing a structural model of the concrete wind tunnel according to the material parameters and mechanical parameters; Constructing a fluid calculation model including a turbulence calculation model and control equations, wherein the control equations include: a mass conservation equation, a momentum conservation equation, and an energy conservation equation; 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; 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: 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.

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 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.

4. 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 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.

5. 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 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.

6. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 5 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.

7. The method for acquiring temperature field of concrete cave wall based on fluid heat transfer coupling according to claim 6 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.

8. 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 7; 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.

Images