A high-fidelity modeling and verification method for autoclave models

Abstract

The present invention discloses a high-fidelity modeling and verification method for an autoclave model, which relates to the field of autoclave simulation. The method comprises: measuring the wind speed at the autoclave door; establishing a high-fidelity autoclave model and a simplified cylindrical model respectively according to the autoclave size parameters and characteristic structure, and defining boundaries for the two models respectively; measuring the temperature and convective heat transfer coefficient at different positions in the autoclave by a calorimeter; defining the resulting high-fidelity autoclave model and simplified cylindrical model in computational fluid dynamics software, using the obtained wind speed as the inlet wind speed of the model, and performing steady-state convective heat transfer coefficient and transient temperature simulation respectively; comparing the simulation results with the measurement results to verify the simulation accuracy of the high-fidelity autoclave model and the simplified cylindrical model for the convective heat transfer coefficient and temperature distribution. The high-fidelity autoclave simulation model proposed by the present invention can effectively improve the prediction accuracy of the convective heat transfer coefficient and temperature distribution in the autoclave.

Description

Technical Field

[0001] The present invention belongs to the field of autoclave simulation, and in particular relates to a high-fidelity modeling and verification method for an autoclave model. Background Art

[0002] Composite materials are widely used in the aerospace field due to their advantages such as high specific strength, corrosion resistance and good fatigue resistance. Autoclave curing molding is currently the main process for the molding of large thermosetting resin-based composite structures for aviation. Forced convection of the fluid in the autoclave is the main source of heat transfer during the curing process, with the convection heat transfer coefficient (HTC) as its basic characteristic. Due to the shadow effect of the molding die geometry and the influence of the position in the autoclave, the convection heat transfer coefficient varies greatly in space, resulting in uneven temperature distribution during the curing of large composite materials. Excessive temperature gradients will produce residual stress and deformation, affecting the mechanical properties of the composite material.

[0003] With the advancement of computer technology, thermal optimization of composite material curing processes using numerical simulations has significantly improved efficiency and reduced costs compared to traditional empirical and experimental methods for reducing composite material curing deformation. The application of thermal boundary conditions in curing simulations significantly affects the accuracy of the results. Because the autoclave molding process involves an unsteady conjugate heat transfer process, computational fluid dynamics (CFD) is essential for studying the spatiotemporal distribution of heat transfer (HTC) within the autoclave to provide accurate thermal boundary conditions for curing simulations.

[0004] Han Ning et al. proposed a CFD model for the autoclave process to predict and optimize the temperature distribution of large frame molds (Han N, An L, Fan L, et al. Research on Temperature Field Distribution in a Frame Mold during Autoclave Process, Materials, Multidisciplinary Digital Publishing Institute, 2020, 13(18): 4020). However, the autoclave was modeled as a cylinder in this scheme, and the effect of model simplification on HTC distribution was not considered.

[0005] Zhu Junhong et al. conducted high-fidelity modeling of an annular duct autoclave and used a calorimeter to measure HTC for accuracy verification (Zhu J, Frerich T, Herrmann A S. CFD modeling and validation of heat transfer inside an autoclave based on a mesh independency study, Journal of Composite Materials, 2021, 55(18): 2469–2487). However, the three locations where HTC was measured in this study were at the same height, which limited the experimental results.

[0006] Therefore, in view of the above shortcomings, it is urgent to provide a high-fidelity modeling technology method for the autoclave model to realize the study of the spatiotemporal distribution of HTC and verify the model accuracy through effective experimental means. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the prior art and provide a high-fidelity modeling and verification method for autoclave models. This method establishes a high-fidelity autoclave model based on the autoclave's dimensional parameters and characteristic structure. The model's accuracy is verified through calorimetry experiments, improving the accuracy of predicting the HTC distribution within the autoclave.

[0008] The specific technical solutions adopted in the present invention are as follows:

[0009] In a first aspect, the present invention provides a high-fidelity modeling and verification method for an autoclave model, as follows:

[0010] S1: Measure the wind speed at the autoclave door;

[0011] S2: Based on the autoclave size parameters and characteristic structure, a high-fidelity autoclave model and a simplified cylindrical model are established, and boundaries are defined for the two models.

[0012] S3: Measure the temperature and convection heat transfer coefficient at different locations in the autoclave using a calorimeter;

[0013] S4: Define the high-fidelity autoclave model and simplified cylindrical model obtained in S2 in the computational fluid dynamics software. Use the wind speed obtained in S1 as the inlet wind speed of the model to simulate the steady-state convective heat transfer coefficient and transient temperature respectively.

[0014] S5: Compare the simulation results in S4 with the measured results in S3 to verify the simulation accuracy of the high-fidelity autoclave model and the simplified cylindrical model for the convective heat transfer coefficient and temperature distribution.

[0015] Preferably, in S1, a Testo 405i anemometer is used to measure the wind speed.

[0016] Preferably, in S2, the high-fidelity autoclave model and the simplified cylindrical model are both established using ANSYS-Spaceclaim software, and the boundaries include the inlet, outlet, wall, and fluid-solid coupling interface.

[0017] Preferably, in S3, the Biot number Bi of the calorimeter is equivalent to the surface convection heat transfer coefficient h of the calorimeter multiplied by the ratio of the characteristic length l to the thermal conductivity k of the aluminum plate, and the Biot number Bi is less than 0.1;

[0018] The surface convection heat transfer coefficient The heat q passing through the contact area A of the aluminum plate and the fluid per unit time and the fluid temperature T f and aluminum plate temperature T s When the Biot number Bi is less than 0.1, the heat q is equivalent to the mass m of the aluminum plate and the specific heat capacity c of the aluminum plate. p The product of the aluminum plate heating rate dT / dt.

[0019] Preferably, the calorimeter comprises an aluminum plate, a thermocouple and a silicone foam plate arranged on a stainless steel bracket; the length, width and height of the aluminum plate are 240 mm, 240 mm and 30 mm respectively, and the thickness of the silicone foam plate is 10 mm; the aluminum plate is placed in the middle of the stainless steel bracket, and the bottom is padded with silicone foam plates to insulate it from the stainless steel bracket, and the four circumferential sides are respectively covered with silicone foam plates to create one-dimensional heat transfer along the thickness direction of the aluminum plate; the thermocouple model is J-type, and the working end is located at the center of the aluminum plate.

[0020] Preferably, in S3, the test positions of the calorimeter are 9 positions on the central axis of the autoclave with varying distances in the length and height directions.

[0021] Preferably, in S4, the computational fluid dynamics software is ANSYS-FLUENT, and the contents of defining the two models include:

[0022] Inlet boundary conditions, outlet boundary conditions, wall boundary conditions, solid domain material properties, fluid domain material properties, turbulence model, reference pressure and process temperature profile;

[0023] The material properties of the solid domain include specific heat capacity, thermal conductivity and density; the material properties of the fluid domain include density, specific heat capacity, thermal conductivity and viscosity.

[0024] In a second aspect, the present invention provides a computer program product, comprising a computer program / instruction, which, when executed by a processor, can implement the high-fidelity modeling and verification method of the autoclave model as described in any one of the first aspects.

[0025] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the high-fidelity modeling and verification method of the autoclave model as described in any one of the first aspects is implemented.

[0026] In a fourth aspect, the present invention provides a computer electronic device comprising a memory and a processor;

[0027] The memory is used to store computer programs;

[0028] The processor is configured to implement the high-fidelity modeling and verification method of the autoclave model as described in any one of the first aspects when executing the computer program.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The high-fidelity autoclave model provided by the present invention comprehensively considers the dimensional parameters and structural characteristics of the autoclave physical model, and is more accurate in describing the flow field characteristics and predicting the HTC distribution than the traditional cylindrical simplified model.

[0031] (2) The present invention uses commercial ANSYS software for simulation modeling and calculation, which has a clear process, low requirements on programming skills, and strong versatility.

[0032] (3) The calorimeter verification method provided by the present invention has low material requirements and wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below with reference to the accompanying drawings.

[0034] Figure 1 is a schematic flow chart of a high-fidelity modeling and verification method for an autoclave model of the present invention;

[0035] Figure 2 It is a high-fidelity model of the autoclave in the embodiment of the present invention;

[0036] Figure 3 : This is the modeling of the characteristic H-Slot structure of the autoclave in the embodiment of the present invention; (a) is the H-Slot structure near the autoclave door, and (b) is the H-Slot structure near the autoclave tail;

[0037] Figure 4 : is a simplified cylindrical model of the autoclave in an embodiment of the present invention;

[0038] Figure 5 is a schematic structural diagram of a calorimeter in an embodiment of the present invention;

[0039] Figure 6 Schematic diagram of various positions of the calorimeter for measuring HTC in an autoclave according to an embodiment of the present invention;

[0040] Figure 7 is a steady-state flow field distribution diagram simulated by a high-fidelity model in an embodiment of the present invention;

[0041] Figure 8 1 is a steady-state flow field distribution diagram simulated by a simplified cylindrical model in an embodiment of the present invention;

[0042] Figure 9 In the embodiment of the present invention, Figure 6 Comparison of transient simulation temperature and experimental results of high-fidelity model and simplified cylindrical model at position ⑤.

[0043] The reference numerals in the figure are: aluminum plate 13, thermocouple 14, silicone foam plate 15, stainless steel bracket 16. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0045] like Figure 1 As shown in FIG, a high-fidelity modeling and verification method for an autoclave model provided by the present invention is as follows:

[0046] S1: Measure the wind speed at the autoclave door.

[0047] As a preferred embodiment of the present invention, in this step, a Testo 405i anemometer can be used to measure the wind speed, and the measured wind speed is used as a simulation input parameter in the subsequent step S4.

[0048] S2: Based on the autoclave size parameters and characteristic structure, a high-fidelity autoclave model and a simplified cylindrical model are established, and boundaries are defined for the two models.

[0049] As a preferred embodiment of the present invention, in this step, the high-fidelity autoclave model and the simplified cylindrical model are both established using ANSYS-Spaceclaim software, and the boundaries that need to be defined include the inlet, outlet, wall, and fluid-solid coupling interface.

[0050] S3: Measure the temperature and convection heat transfer coefficient at different locations in the autoclave using a calorimeter.

[0051] As a preferred embodiment of the present invention, a calorimeter is prepared using an aluminum plate 13, an insulating silica gel foam plate 15 and a thermocouple 14, as follows:

[0052] The calorimeter primarily consists of an aluminum plate 13, a thermocouple 14, and a silicone foam plate 15, mounted on a stainless steel bracket 16. The length, width, and height of the aluminum plate 13 are 240 mm, 240 mm, and 30 mm, respectively, and the thickness of the silicone foam plate 15 is 10 mm. The aluminum plate 13 is placed in the center of the stainless steel bracket 16, with the silicone foam plate 15 providing insulation from the bracket. The four circumferential sides are covered with silicone foam plates 15 to create one-dimensional heat transfer along the thickness of the aluminum plate 13. The thermocouple 14 is J-type, with the working end located in the center of the aluminum plate 13.

[0053] As a preferred embodiment of the present invention, in this step, the Biot number Bi of the calorimeter is the ratio of the internal thermal resistance of the solid to the surface thermal resistance of the convection heat transfer. Assuming that the characteristic length l of the calorimeter and the thermal conductivity k of the aluminum plate are known, and the convection heat transfer coefficient h is obtained through experimental measurement, the Biot number Bi is equivalent to the surface convection heat transfer coefficient h of the calorimeter multiplied by the ratio of the characteristic length l to the thermal conductivity k of the aluminum plate, and the Biot number Bi is less than 0.1. It is specifically expressed as the following formula:

[0054]

[0055] The convection heat transfer coefficient h is used to describe the convection heat transfer capacity between the fluid and the solid surface. Based on Newton's law of cooling, it is defined as the ratio of the heat q passing through area A per unit time to the temperature difference between the fluid and the solid surface. When Bi < 0.1 is met, based on the law of conservation of energy, the change in internal energy is manifested as a change in temperature. The heat q is equivalent to the mass m of the aluminum plate and the specific heat capacity c of the aluminum plate. p The product of the aluminum plate heating rate dT / dt is expressed as follows:

[0056]

[0057] Among them, m is the mass of the aluminum plate, c p is the specific heat capacity of the aluminum plate, dT / dt is the heating rate of the aluminum plate, A is the contact area between the aluminum plate and the fluid, T f is the fluid temperature, T sis the temperature of the aluminum plate.

[0058] As a preferred embodiment of the present invention, the test positions of the calorimeter are 9 positions on the central axis of the autoclave with varying distances in the length and height directions.

[0059] S4: Define the high-fidelity autoclave model and simplified cylindrical model obtained in S2 in the computational fluid dynamics software, use the wind speed obtained in S1 as the inlet wind speed of the model, and perform steady-state convective heat transfer coefficient and transient temperature simulation respectively.

[0060] As a preferred embodiment of the present invention, the computational fluid dynamics software is ANSYS-FLUENT, and the contents of defining the two models by the software include:

[0061] Inlet and outlet boundary conditions, wall boundary conditions, solid domain material properties, fluid domain material properties, turbulence model, reference pressure, and process temperature profile. Solid domain material properties include specific heat capacity, thermal conductivity, and density, while fluid domain material properties include density, specific heat capacity, thermal conductivity, and viscosity.

[0062] S5: Compare the simulation results in S4 with the measured results in S3 to verify the simulation accuracy of the high-fidelity autoclave model and the simplified cylindrical model for the convective heat transfer coefficient and temperature distribution.

[0063] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention may be combined accordingly, provided that there is no conflict between them.

[0064] Example 1

[0065] This embodiment uses the high-fidelity modeling and verification method of the autoclave model of the present invention to perform high-fidelity modeling of the autoclave model, and uses a calorimeter to verify its simulation accuracy. The autoclave used in this embodiment is EC 1.5m 2 m autoclave (ASC, USA), dimensions as Figure 2 Indicated by a and b, where a=2 m is the length of the autoclave and b=1.5 m is the cross-sectional diameter of the autoclave. Figure 1 As shown, it mainly includes the following steps:

[0066] S1. Measurement of wind speed at the autoclave door:

[0067] At normal temperature and pressure, a Testo 405i anemometer was used to measure the wind speed at three different locations below the autoclave floor outlet. The measurement time was 5 min. The measurement results are shown in Table 1. 6.61 m / s was taken as the simulated inlet wind speed.

[0068] Table 1 Wind speed measurement results

[0069]

[0070] S2. Establish an autoclave model based on the autoclave size parameters and characteristic structure, as follows:

[0071] ANSYS-Spaceclaim commercial software was used to build a high-fidelity autoclave model and a simplified cylindrical model. Figure 2 This is a high-fidelity model that takes into account the autoclave H-Slot structure, elliptical head, and bottom air duct structure. The H-Slot structure is simplified to a two-dimensional perforated baffle, and the autoclave outlet is extended to suppress backflow. The H-Slot modeling details of the high-fidelity model are as follows: Figure 3 As shown, H-Slot 前 and H-Slot 后 They represent the H-Slot structures near the autoclave door and the autoclave tail. 前 The opening area on the autoclave gradually decreases from the bottom to the top. 后 The opening area on the surface gradually increases from the center to the periphery. The high-fidelity model in this step retains this opening feature during the modeling process. Figure 4 This is a simplified cylindrical model obtained by simulating only the internal cavity of the autoclave in this step.

[0072] S3. Preparation of calorimeter and measurement of HTC distribution in autoclave, as follows:

[0073] In this embodiment, the structure of the calorimeter is as follows Figure 5 As shown in the figure, the aluminum plate 13 is made of 6061 aluminum alloy, with length, width, and height dimensions of c = 240 mm, d = 240 mm, and e = 30 mm, respectively. The thickness f of the silicone foam sheet 15 is 10 mm. The aluminum plate 13 is placed in the center of the stainless steel bracket 16, with the bottom edge of the silicone foam sheet 15 providing thermal insulation between the plate and the bracket 16. The silicone foam sheet 15 is cut to length and width dimensions of 240 mm and 30 mm, respectively, and then covers the four circumferential sides of the aluminum plate 13. A thermocouple 14 is inserted into the center of the aluminum plate, creating one-dimensional heat transfer along the thickness of the plate 13. The thermocouple 14 is J-shaped, with a length h of 50 mm and a working end located at the center of the aluminum plate 13. The four support legs at the bottom of the stainless steel bracket 16 are square in cross-section, with a side length g of 15 mm. The stainless steel bracket 16 keeps the bottom surface of the calorimeter away from the autoclave floor, allowing free airflow over the upper and lower surfaces of the calorimeter.

[0074] During the HTC measurement process, the calorimeter is placed on the central axis of the autoclave. In order to obtain the distribution of HTC in the autoclave space, such as Figure 6As shown in Figure 1, HTCs were measured at nine locations (① to ⑨), where l = 1.5 m, m = 1.0 m, n = 0.5 m, p = 0.67 m, q = 0.46 m, and r = 0.21 m.

[0075] During the actual measurement, the temperature was raised from room temperature to 180°C at a rate of 1°C / min, held for 10 minutes, and then rapidly cooled at a rate of 5°C / min. A constant pressure of 0.7 MPa was applied during the entire process. Only the HTC during the heating process was calculated, and the results are shown in Table 2.

[0076] Table 2 HTC at various locations measured by calorimeter experiment

[0077]

[0078] in, is the average temperature difference between the air thermocouple and the calorimeter thermocouple during the heating phase measured experimentally. , it can be assumed that the temperature of the calorimeter is uniform.

[0079] At a height of 0.21 m, the average HTC values ​​of positions ①, ②, and ③ are , HTC changes slightly. At the heights of 0.46 m and 0.67 m, the average HTC values ​​are and . As the height increases from 0.21 m to 0.67 m, the average HTC value decreases and the standard deviation increases. The size of HTC is closely related to the fluid flow rate. Increasing the flow rate can enhance the heat exchange capacity between the fluid and the solid, thereby producing a larger HTC. Therefore, the fluid flow rate is relatively high near the floor at the bottom of the autoclave, and flows evenly from the tank door to the tank tail, resulting in a small difference in HTC between positions ①, ② and ③. In the middle and upper areas of the autoclave, the formation of vortices causes the flow rate to decrease and the fluctuation to increase, causing the HTC measured at heights of 0.46 m and 0.67 m to be lower than 0.21 m and the standard deviation to increase.

[0080] S4. CFD-based steady-state HTC and transient temperature field simulation, as follows:

[0081] The coupled model of the autoclave and calorimeter is defined to place the model in a near-real production environment, thereby improving the reliability of the prediction results. In this embodiment, the definitions include inlet boundary conditions, outlet boundary conditions, wall boundary conditions, solid domain material properties, fluid domain material properties, turbulence model, reference pressure, and process temperature curve. Among them, solid domain material properties include specific heat capacity, thermal conductivity, and density; fluid domain material properties include density, specific heat capacity, thermal conductivity, and viscosity. In this embodiment, the inlet and outlet boundary conditions are preferably: velocity inlet and pressure outlet. The material properties are shown in Table 3.

[0082] Table 3 Thermal properties of materials

[0083]

[0084] Where ρ is the material density, Cp is the specific heat capacity, k is the thermal conductivity, and μ is the dynamic viscosity. , , , , , , , .

[0085] In this embodiment, the fluid flow state is determined by the Reynolds number:

[0086]

[0087] in, is the Reynolds number, is the fluid density, is the fluid velocity, is the hydraulic diameter, is the dynamic viscosity of the fluid. In this embodiment, the Reynolds numbers of the high-fidelity model and the simplified cylindrical model are and , are both greater than 12000, indicating that the fluid is in a turbulent state. In this embodiment, the Spalart-Allmaras turbulence model is selected.

[0088] Based on the HTC experiment measured by the calorimeter, the reference pressure is 0.7 MPa. Under steady-state solution, the inlet temperature does not change with time, and 60°C is preferably used as the inlet temperature condition. The autoclave wall and the side walls of the calorimeter are adiabatic and non-slip walls, and the upper and lower surfaces of the calorimeter are constant temperature walls:

[0089]

[0090] in, , is the experimentally measured average temperature difference between the air thermocouple and the calorimeter thermocouple during the heating phase. Preferably, the average temperature difference is calculated when the calorimeter heating rate reaches 1°C / min.

[0091] In a transient solution, the inlet temperature changes with time. A UDF (user-defined function) is used to define a temperature ramp from room temperature to 180°C at a rate of 1°C / min, with the temperature held constant for 10 minutes. The autoclave walls and calorimeter sidewalls are adiabatic and no-slip, while the upper and lower surfaces of the calorimeter are fluid-structure coupled. The simulation outputs temperature-time curves at the inlet and calorimeter centers.

[0092] S5. Compare the steady-state HTC and transient temperature results in S4 with the experimental results in S3 to verify the simulation accuracy, as follows:

[0093] The steady-state flow fields obtained using the high-fidelity model and the simplified cylindrical model are shown in Figure 2. Figure 7 and Figure 8 As shown. The high-fidelity model simulates the complex flow field in the autoclave and is consistent with the prediction of the flow field by the HTC distribution measured by the calorimeter. The H-Slot structure divides the flow process into three stages. In the first stage, the fluid enters the elliptical head from the inlet. It is observed that the streamlines are dense near the elliptical head contour and the flow velocity is about 6 m / s. The fluid contacts the H-Slot 前 After the structure, part of the fluid generates vortex in the center of the elliptical head, and the other part passes through the H-Slot 前 The opening on the structure leads to the air duct in the autoclave. In the second stage, it is observed that the flow velocity at the bottom of the duct is relatively high, about 4 m / s, and the fluid flows evenly along the bottom to the tail end of the autoclave. The streamline is close to the H-Slot 后 On the left side of the duct, there is a vortex that deflects to the left. 前 The opening area of ​​the structure gradually increases from top to bottom, making it easier for fluid to pass through the H-Slot. 前 The bottom of the air flow into the air duct, thus forming a uniform flow field at the bottom of the air duct. 后 The opening area of ​​the structure gradually increases from the center to the surroundings, and the opening area at the top is larger than that at the bottom. Therefore, the fluid at the bottom of the duct is closer to the H-Slot. 前 The structure deflects upwards. 前 The opening area on the right side of the structure is larger than that on the left side, so that the fluid entering the air duct through the opening on the right side has a higher flow rate. 后 After blocking, a vortex deflected to the left is formed in the air duct. In the third stage, the fluid passes through the H-Slot 后 The structure has openings that enter the rear end of the autoclave and leave the fluid domain through the outlet.

[0094] The flow field simulated by the simplified cylindrical model shows a uniform flow from the inlet to the outlet, with eddies only generated near the calorimeter. This flow field deviates significantly from the actual situation.

[0095] The comparison between the steady-state HTC calculation results and the experimental results of the two autoclave models is shown in Table 4.

[0096] Table 4 Comparison of steady-state HTC simulations using the high-fidelity model and the simplified cylindrical model with experimental results

[0097]

[0098] Among them, HTC 实验 HTC is the experimentally measured HTC, 高保真 HTC is obtained from the steady-state simulation of the high-fidelity model, HTC 圆柱状 The HTC obtained from the steady-state simulation of a simplified cylindrical model. The values ​​in brackets are the relative errors between the simulation and experimental results.

[0099] The simulation results of the high-fidelity model reflect the dependence of HTC on the position. As the position in the autoclave changes from the bottom to the top, the HTC changes from down to The maximum relative error is located at Figure 6 At position ③ in the figure, it is about 35%. Due to the rectifying effect of the H-Slot structure, the streamlines near the autoclave floor area are close to a straight line, which is consistent with the streamlines of the simplified cylindrical model. Figure 6 At positions ①, ②, and ③ in the figure, the HTC simulated by the simplified cylindrical model agrees well with the experimental results. At other positions, the cylindrical model fails to simulate the eddy flow within the autoclave, resulting in a relative error of 30% to 80% between the simulation and experimental results.

[0100] The transient temperature at position ⑤ simulated by the high-fidelity model and the simplified cylindrical model is as follows: Figure 9 The average temperature error and maximum temperature error between the simulation results and the experimental results are shown in the bar graph. The average temperature error and maximum temperature error between the simulation results and the experimental results at all locations are shown in Table 5.

[0101] Table 5 Average and maximum errors between transient simulation temperature and experimental temperature

[0102]

[0103] High-fidelity models in Figure 6 The average temperature error range of positions ①~⑨ is 1~4 ℃, and the maximum temperature error is less than 10 ℃. Figure 6 The average temperature error at positions ① to ⑨ ranges from 4 to 9 °C, and the maximum temperature error is from 8 to 14 °C. The average and maximum temperature errors between the simulation results and the experimental results at each position for the high-fidelity model are lower than those for the simplified cylindrical model.

[0104] This example establishes a high-fidelity model of an autoclave and verifies its feasibility through calorimetry experiments. Compared to traditional simplified cylindrical models, this high-fidelity model significantly improves the simulation accuracy of both steady-state HTC and transient temperature, meeting the research needs for HTC and temperature distribution within the autoclave.

[0105] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A high-fidelity modeling and verification method for an autoclave model, characterized in that: The details are as follows: S1: Measure the wind speed at the autoclave door; S2: Based on the autoclave size parameters and characteristic structure, a high-fidelity autoclave model and a simplified cylindrical model are established, and boundaries are defined for the two models. S3: Measure the temperature and convection heat transfer coefficient at different locations in the autoclave using a calorimeter; S4: Define the high-fidelity autoclave model and simplified cylindrical model obtained in S2 in the computational fluid dynamics software. Use the wind speed obtained in S1 as the inlet wind speed of the model to simulate the steady-state convective heat transfer coefficient and transient temperature respectively. S5: Compare the simulation results in S4 with the measured results in S3 to verify the simulation accuracy of the high-fidelity autoclave model and the simplified cylindrical model for the convective heat transfer coefficient and temperature distribution; In S3, the Biot number of the calorimeter Bi Equivalent to the convective heat transfer coefficient of the calorimeter surface h Multiply by the characteristic length l Thermal conductivity of aluminum plate k The ratio of , and satisfy the Biot number Bi Less than 0.1; The convective heat transfer coefficient h The contact area between the aluminum plate and the fluid per unit time A Calories q and fluid temperature T f and aluminum plate temperature T s the ratio of the differences; When the Biot number is satisfied Bi When the heat is less than 0.1, q Equivalent to the mass of aluminum plate m Specific heat capacity of aluminum plate c p and aluminum plate heating rate dT / dt The product of .

2. The high-fidelity modeling and verification method for an autoclave model according to claim 1, wherein: In S1, a Testo 405i anemometer is used to measure wind speed.

3. The high-fidelity modeling and verification method of an autoclave model according to claim 1, characterized in that: In S2, the high-fidelity autoclave model and the simplified cylindrical model were both established using ANSYS-Spaceclaim software, and the boundaries included the inlet, outlet, wall, and fluid-solid coupling interface.

4. The high-fidelity modeling and verification method for an autoclave model according to claim 1, wherein: The calorimeter comprises an aluminum plate (13), a thermocouple (14) and a silicone foam plate (15) arranged on a stainless steel bracket (16); the length, width and height of the aluminum plate (13) are 240 mm, 240 mm and 30 mm respectively, and the thickness of the silicone foam plate (15) is 10 mm; the aluminum plate (13) is placed in the middle of the stainless steel bracket (16), and the bottom is padded with silicone foam plates (15) to insulate the stainless steel bracket (16), and the four circumferential sides are respectively covered with silicone foam plates (15) to create one-dimensional heat transfer along the thickness direction of the aluminum plate (13); the thermocouple (14) is J-type, and the working end is located at the center of the aluminum plate (13).

5. The high-fidelity modeling and verification method of an autoclave model according to claim 1, characterized in that: In S3, the test positions of the calorimeter are 9 positions on the central axis of the autoclave with varying distances in the length and height directions.

6. The high-fidelity modeling and verification method of an autoclave model according to claim 1, characterized in that: In S4, the computational fluid dynamics software is ANSYS-FLUENT, and the contents of defining the two models include: Inlet boundary conditions, outlet boundary conditions, wall boundary conditions, solid domain material properties, fluid domain material properties, turbulence model, reference pressure and process temperature profile; The material properties of the solid domain include specific heat capacity, thermal conductivity and density; the material properties of the fluid domain include density, specific heat capacity, thermal conductivity and viscosity.

7. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the high-fidelity modeling and verification method of the autoclave model according to any one of claims 1 to 6 can be implemented.

8. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and when the computer program is executed by the processor, the high-fidelity modeling and verification method of the autoclave model according to any one of claims 1 to 6 is implemented.

9. A computer electronic device, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is configured to implement the high-fidelity modeling and verification method for the autoclave model according to any one of claims 1 to 6 when executing the computer program.

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