Three-dimensional human body heat transfer simulation method
By constructing a three-dimensional human body model with blocks and layered layers and building equivalent main blood vessels, the problem of difficulty in simulating the internal heat generation and transfer of the human body in the prior art is solved, and a more refined temperature and heat flow distribution simulation is achieved, meeting the needs of thermal comfort design.
Patent Information
- Application Number
- CN202411737536.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-04-22
AI Technical Summary
The prior art is difficult to refinely simulate the heat generation and transfer process inside the three-dimensional human body, especially because the human body parts and tissues are highly simplified, and the body surface temperature and heat flow distribution cannot be obtained in detail.
By constructing a three-dimensional human solid model close to a real person, layer it in pieces, and constructing equivalent main blood vessels inside the model, setting thermal physical properties parameters, and simulating the heat generation and transfer characteristics inside the human body.
It realizes a more realistic three-dimensional human skin temperature and heat flow distribution more in line with the actual, meeting the need for details control of thermal comfort design.
Smart Images
Figure CN119862810A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of simulation technology, and in particular to a three-dimensional human body heat transfer simulation method. Background Art
[0002] Research on human thermal response includes human thermal physiological testing, human thermal regulation modeling, warm mannequin testing and CFD simulation. At present, CFD simulation is mainly used for heat exchange calculation between the human body surface and the flow field in which the human body is located. The heat generation and transfer calculation inside the human body is mainly completed through the human body thermal regulation model. The human body thermal regulation model roughly divides the human body into finite calculation nodes according to different parts and tissues. The heat transfer analysis between tissues is converted into heat transfer calculation between nodes, and the heat generation in the tissue is simplified to the increase of node heat. The application of the human body thermal regulation model has promoted the development of thermal comfort research, but because the parts and tissues of the human body are highly simplified, the details of the surface temperature and heat flow distribution of the human body are often not obtained through the human body thermal regulation model. With the continuous development of design requirements, human thermal comfort design is increasingly dependent on the control of the details of the surface temperature and heat flow distribution. On the other hand, under the current technical background, it is not realistic to fully use CFD simulation to perform highly anthropomorphic heat transfer simulation. For example, the complex flow heat exchange process modeling and huge computing resource consumption corresponding to the heat transfer of blood flowing in the form of fluid inside the blood vessel basically negate the attempt of fully anthropomorphic three-dimensional human body heat transfer simulation. Summary of the invention
[0003] Purpose of the Invention
[0004] In order to simulate the heat generation and transfer process inside a three-dimensional human body, the present invention provides a three-dimensional human body heat transfer simulation method.
[0005] Inventing technical solutions
[0006] A three-dimensional human body heat transfer simulation method comprises the following steps:
[0007] 1) Construct a three-dimensional human body model that is close to real people based on human body posture and actual shape;
[0008] 2) Divide the three-dimensional human body model into several parts;
[0009] 3) Based on the reduced thickness, each divided part is divided into several layers from the skin surface inward, so that the solid block corresponding to each part is further decomposed into several sub-blocks;
[0010] 4) In the three-dimensional human body after the above block and layering, the main blood vessel axis with a diameter greater than N mm is further constructed according to the actual human blood vessel characteristics (the N value is selected according to the computer performance), and the main blood vessel axis is subdivided into M segments according to size and shape (the M value is set according to needs), and each segment is replaced by a heat-conducting cylinder of different diameters. The above cylinders are marked as arterial blood vessels and venous blood vessels according to the real human body characteristics;
[0011] 5) Meshing and assembling the above three-dimensional human body model including arteries and veins to form a three-dimensional mesh that can be imported into simulation software for calculation;
[0012] 6) Set the thermal physical parameters of different layers inside the 3D human body model in the simulation software to simulate the heat generation and transfer characteristics of different parts and tissues of the actual human body.
[0013] Preferably, in step 2), the parts are divided into the head, neck, chest, abdomen, left upper arm, left lower arm, left hand, right upper arm, right lower arm, right hand, left thigh, left calf, left foot, right thigh, right calf, and right foot.
[0014] Preferably, in step 3), the skin is divided into four layers from the skin surface inwards, namely, the skin layer, the fat layer, the muscle layer and the core layer.
[0015] Preferably, the thermophysical property parameters in step 6) include density, specific heat, thermal conductivity and heat generation rate.
[0016] Preferably, in step 6), for the arterial tube and the venous tube, the anisotropic thermal conductivity value is set along the radial and axial directions of the cylindrical segment according to the blood flow direction, and the density, specific heat and heat generation rate are set.
[0017] Preferably, in step 4), the diameter of each section of the cylinder is the equivalent diameter of the corresponding blood vessel.
[0018] Preferably, all cylinders constitute an equivalent main blood vessel, and a Boolean operation is performed on the skin layer, fat layer, muscle layer and core layer using the equivalent main blood vessel to generate a blood vessel layer that is distinct from the skin layer, fat layer, muscle layer and core layer.
[0019] Preferably, in actual use, meshing software is used to perform meshing and assembly of each entity area of the model to form a human body internal calculation domain containing multiple solid domains. Finally, the merged mesh of the human body model and the fluid domain in which the human body model is located is imported into the CFD software. After parameter setting, the heat generation and transfer characteristics of different parts and tissues of the actual human body are simulated.
[0020] Preferably, the infrared emissivity of the human body surface and other boundary conditions can be set in step 6) as needed, and the human body surface temperature and heat flux density distribution can be obtained by simulation. Other boundary conditions include the equivalent convection heat transfer coefficient covering the evaporation of skin sweat and the external environment temperature of the human body.
[0021] Preferably, in step 3), the thickness of each layer is calculated and set according to its volume proportion in the part.
[0022] Advantages of the present invention: The method can achieve a more realistic and refined simulation of three-dimensional human skin temperature and heat flow distribution. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a schematic diagram of dividing the three-dimensional human body entity into blocks according to parts of the present invention.
[0024] Figure 2 It is a schematic diagram of the lower abdomen according to tissue layers of the present invention.
[0025] Figure 3 It is a schematic diagram of main blood vessel modeling of the present invention.
[0026] In the figure, 1-head, 2-neck, 3-chest, 4-abdomen, 5-right upper arm, 6-right lower arm, 7-right hand, 8-left upper arm, 9-left lower arm, 10-left hand, 11-right thigh, 12-right calf, 13-right foot, 14-left thigh, 15-left calf, 16-left foot, 17-skin layer, 18-fat layer, 19-muscle layer, 20-core layer, 21-real human blood vessels, 19-equivalent human blood vessels. DETAILED DESCRIPTION
[0027] The present invention is achieved through the following technical solutions.
[0028] A three-dimensional human body heat transfer simulation method mainly involves dividing a three-dimensional human body entity similar to a real human body into blocks according to parts and stratifying each part according to tissue structure, as well as constructing equivalent blood vessels equivalent to the main blood vessels of a real human body inside the three-dimensional entity.
[0029] In this embodiment, a three-dimensional human body entity in a standing position (see Figure 1 ) to describe. Figure 1 As shown in the figure, the three-dimensional human body model is divided into 16 pieces according to different parts.
[0030] In this embodiment, the stratification operation for the three-dimensional human body according to the differences in its tissue structure is performed on the above-divided entity blocks. Figure 2A schematic diagram of the lower abdomen is provided, which is divided from the outside to the inside into a skin layer 17, a fat layer 18, a muscle layer 19, and a core layer 20. In the layering operation, the thickness of a single tissue layer in a specific part is uniform, and the thickness of different tissue layers is different. Among them, the thickness of a certain layer is converted and set according to its volume proportion in the part. The thickness of the same tissue layer in different parts is generally different.
[0031] After the above two steps, the 3D human body entity is divided into 64 sub-blocks. Furthermore, a real blood vessel path with a diameter greater than 5 mm is extracted inside the 3D human body entity, and an equivalent main blood vessel consisting of a segmented cylinder with a variable diameter is created with the path as the axis. The equivalent main blood vessel is constructed inside the 3D human body and overlaps with the above different human tissues. The overlapping part is the equivalent blood vessel model, that is, the equivalent main blood vessel is used to perform Boolean operations on the above tissues to generate a blood vessel layer that is different from the skin layer 17, fat layer 18, muscle layer 19 and core layer 20 tissues.
[0032] In this embodiment, after the above human body model is constructed, the meshing software is used to mesh and assemble the model's various solid regions to form a human body internal calculation domain containing multiple solid domains. Finally, the merged mesh of the human body model and the fluid domain in which the human body model is located is imported into the CFD software, and after parameter setting, the heat generation and transfer characteristics of different parts and tissues of the actual human body are simulated.
[0033] For the human body heat transfer model, the density, thermal conductivity, specific heat and heat generation rate of other solid domains except the vascular layer are differentiated according to different tissues, where the thermal conductivity is isotropic; for the vascular layer, the anisotropic thermal conductivity and density, specific heat and heat generation rate of the solid domain are set along the flow axis and radial direction.
[0034] The infrared emissivity of the human body surface and other boundary conditions are set, and the temperature and heat flux density distribution of the human body surface are obtained through simulation.
[0035] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable technicians familiar with the technical field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit and essence of the present invention should be included in the protection scope of the present invention. The technology, shape, and structure parts not described in detail in the present invention are all well-known technologies.
Claims
1. A three-dimensional human body heat transfer simulation method, characterized in that: The steps include: 1) Construct a three-dimensional human body model that is close to real people based on human body posture and actual shape; 2) Divide the three-dimensional human body model into several parts; 3) Based on the reduced thickness, each divided part is divided into several layers from the skin surface inward, so that the solid block corresponding to each part is further decomposed into several sub-blocks; 4) In the three-dimensional human body after the above block and layering, the main blood vessel axis with a diameter greater than N mm is further constructed according to the actual human blood vessel characteristics, and the main blood vessel axis is subdivided into M segments according to size and shape. Each segment is replaced by a heat-conducting cylinder with a different diameter. The above cylinders are marked as arterial blood vessels and venous blood vessels according to the real human body characteristics; 5) Meshing and assembling the above three-dimensional human body model including arteries and veins to form a three-dimensional mesh that can be imported into simulation software for calculation; 6) Set the thermal physical parameters of different layers inside the 3D human body model in the simulation software to simulate the heat generation and transfer characteristics of different parts and tissues of the actual human body.
2. A three-dimensional human body heat transfer simulation method as claimed in claim 1, characterized in that: In step 2), divide it into head, neck, chest, abdomen, left upper arm, left lower arm, left hand, right upper arm, right lower arm, right hand, left thigh, left calf, left foot, right thigh, right calf, and right foot.
3. A three-dimensional human body heat transfer simulation method as claimed in claim 1, characterized in that: In step 3), the skin layer, fat layer, muscle layer and core layer are divided into four layers from the skin surface to the inside.
4. A three-dimensional human body heat transfer simulation method as claimed in claim 1, characterized in that: The thermal physical property parameters in step 6) include density, specific heat, thermal conductivity and heat generation rate.
5. A three-dimensional human body heat transfer simulation method as claimed in claim 1, characterized in that: In step 6), for the arterial tube and the venous tube, the anisotropic thermal conductivity value is set along the radial and axial directions of the cylindrical segment according to the blood flow direction, and the density, specific heat and heat generation rate are set.
6. A three-dimensional human body heat transfer simulation method as claimed in claim 1, characterized in that: In step 4), the diameter of each cylinder segment is the equivalent diameter of the corresponding blood vessel.
7. A three-dimensional human body heat transfer simulation method as claimed in claim 3, characterized in that: All cylinders constitute equivalent main blood vessels, and Boolean operations are performed on the skin layer, fat layer, muscle layer and core layer using the equivalent main blood vessels to generate blood vessel layers that are distinct from the skin layer, fat layer, muscle layer and core layer.
8. A three-dimensional human body heat transfer simulation method as claimed in claim 1, characterized in that: In actual use, meshing software is used to perform meshing and assembly of each solid area of the model to form a human body internal calculation domain containing multiple solid domains. Finally, the merged mesh of the human body model and the fluid domain in which the human body model is located is imported into the CFD software. After parameter setting, the heat generation and transfer characteristics of different parts and tissues of the actual human body are simulated.
9. A three-dimensional human body heat transfer simulation method as claimed in claim 1, characterized in that: As needed, the infrared emissivity of the human body surface and other boundary conditions can be set in step 6), and the surface temperature and heat flux density distribution of the human body can be obtained by simulation. Other boundary conditions include the equivalent convection heat transfer coefficient covering the evaporation of skin sweat and the external environment temperature of the human body.
10. A three-dimensional human body heat transfer simulation method according to claim 1, characterized in that: In step 3), the thickness of each layer is calculated and set according to its volume proportion in the part.