Constant-temperature anemograph calibration method based on fluid-electricity-heat coupling simulation

Abstract

The invention discloses a constant-temperature anemograph calibration method based on fluid-electric-thermal coupling simulation, and the method comprises the steps: carrying out the modeling of a constant-temperature anemograph from an element to a PCB to a housing of the anemograph through a fluid-electric-thermal coupling simulation method according to the principle that the flow velocity of a flow field and the current have a corresponding relation; and a wind tunnel model used in a real calibration experiment is added in a modeling environment to obtain NTC resistor working current data under different ideal wind speed conditions, so that calibration of the anemograph is completed. According to the invention, compared with a traditional wind tunnel experiment calibration method, the simulation calibration method is lower in cost; the wind speed calibration range is wider and is not limited to experimental conditions; the wind speed environment is an ideal wind speed which is difficult to reach by a traditional wind tunnel, experimental errors are not considered, only iterative errors need to be considered, and the errors can be controlled in an almost negligible range by increasing the number of iterations; the electrothermal coupling method considers the influence of the PCB copper sheet electrical loss on the NTC resistance temperature, and is more reliable than the traditional single thermal field simulation data.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor calibration, and particularly to a calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation. Background Art

[0002] In engineering applications, wind speed measurement technology is an important part. Before using a wind speed measurement sensor, it must be calibrated to ensure accuracy. Large wind tunnels can provide a stable wind speed section, but the calibration cost is too high, and the calibration accuracy is easily affected by various environmental and measurement factors.

[0003] The constant-temperature anemometer has high requirements for sensor calibration, and calibration is required before each use, which puts high demands on the calibration equipment. Therefore, the basic requirements of the calibration wind tunnel are directly related to the working conditions of the wind speed sensor. The measurement range of ordinary anemometers is concentrated in 0-30 m / s, and the range of some hot-wire anemometers reaches 0-60 m / s. This is a wind speed section that is difficult for large wind tunnels to reach. Yu Shice et al. from Zhejiang University developed a small DC calibration wind tunnel in 2014, but the size of this calibration wind tunnel is close to 5 m, and the control system uses active frequency conversion control, which is not only inconvenient to move, but also the active control method has low accuracy; Liu Haiyang et al. from Inner Mongolia Agricultural University designed and tested a movable low-speed wind tunnel in 2016. The size of this calibration wind tunnel also reached 2.63 m, and the wind speed in the experimental section was 0-17.6 m / s. Although the mobility was improved, the calibration range of the calibration wind tunnel decreased a lot. Summary of the Invention

[0004] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide a calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation, which is convenient to apply, has low cost, the calibration wind speed range is not restricted, and the calibration quality is relatively high. It can provide a stable wind speed and is not affected by experimental errors. This has important practical significance for improving the technical level of sensor calibration. To achieve the above object and other advantages according to the present invention, a calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation is provided, including:

[0005] S1. Establish a 3D model of the anemometer;

[0006] S2. Construct and solve the electro-thermal coupling model of the anemometer through the 3D model of the anemometer;

[0007] S3. Construct and solve the electro-thermal coupling model of the anemometer in the simulated wind tunnel model;

[0008] S4. Determine whether the core temperature of the NTC resistor in the thermal analysis result in step S3 is within the specified range. If so, output the wind speed and the corresponding current data; if not, reset the current and repeat steps S2 and S3;

[0009] S5. Repeat steps S3 and S4 to obtain multiple sets of wind speed and corresponding current data;

[0010] S6. Obtain the anemometer calibration result through function fitting. Use Matlab to perform function fitting on the wind speed and current, and complete the anemometer calibration.

[0011] Preferably, step S2 is specifically to import the 3D model of the anemometer into the SIWAVE software; set the initial current and material properties; perform IR-drop electrical simulation calculation by loading excitation conditions on the PCB trace through the SIWAVE software to obtain the PCB power distribution; import the PCB power distribution into the simulation software ICEPAK for PCB board-level thermal simulation to obtain the PCB temperature distribution;

[0012] The i-th electro-thermal co-simulation: Import the PCB temperature distribution of the (i - 1)-th electro-thermal co-simulation into the SIwave software, and perform iterative simulation in the same way as the first electro-thermal co-simulation until the results of the last two electro-thermal co-simulations meet the iterative convergence condition, that is, obtain the PCB copper layer electrical loss result of the electro-thermal coupling co-simulation; where i ≥ 2.

[0013] Preferably, in step S3, use the NX12 software to draw and export the model files of the anemometer housing and the wind tunnel, and add them to the ICEPAK software to redraw the mesh together with the anemometer PCB and the fan; set the wind speed of the fan in the ICEPAK software; set the PCB power to the PCB copper layer electrical loss result after the i-th co-simulation in step S2; perform the thermal field calculation again.

[0014] Preferably, the conductivity in the material properties is set as a function related to temperature; the excitation conditions include an excitation current source and a voltage source; the initial current is the theoretical current value without considering the influence of temperature on the PCB; the performing IR-drop electrical simulation calculation by loading excitation conditions on the PCB trace through the SIwave software includes: obtaining the copper skin electrical loss data of each layer of the PCB.

[0015] Preferably, the importing the PCB power distribution into the simulation software ICEPAK for PCB board-level thermal simulation includes:

[0016] Use SIWAVE to call the ICEPAK solver, set the mesh parameters, the power of each component, and the electro-thermal coupling convergence iteration convergence condition, and then perform mesh drawing and temperature field analysis after the circuit board is powered on; the SIWAVE software automatically starts electro-thermal coupling iterative calculation.

[0017] Preferably, the iterative convergence condition includes: the power difference between the last two electro-thermal co-simulations is less than a threshold value and the temperature difference is less than a threshold value.

[0018] Preferably, when resetting the current, the current needs to be changed in a direction that makes the core temperature of the NTC resistor closer to the specified operating temperature of the NTC resistor. That is, if the core temperature of the NTC resistor is greater than the specified operating temperature of the NTC resistor, the current should be decreased; conversely, the current should be increased until the absolute value of the difference from the specified operating temperature of the NTC resistor is less than a specified small range, and then the wind speed and current data at this time can be output.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: Based on the principle that the energy generated by current heating inside the resistor during the operation of the constant-temperature anemometer can be approximately regarded as the heat taken away by fluid convection heat transfer, multiple software is used to model the anemometer and the wind tunnel model used in the calibration experiment in proportion, and fluid-electric-thermal coupling simulation is carried out. Through multiple co-simulations and iterative optimization of the simulation results, under each given wind speed condition, the simulation results are made to conform to the actual operating temperature of the NTC resistor, so as to simulate the real calibration experiment. This method has low cost; and it is not limited to the wind speed range of the real calibration experiment, making the calibration wind speed range wider; the software-simulated wind speed is an ideal wind speed, the wind speed is stable, and the calibration result is more reliable. Description of the Drawings

[0020] Figure 1 It is a flowchart of the anemometer calibration method based on fluid-electric-thermal coupling simulation shown in the embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the NTC resistor detection circuit in the anemometer shown in the embodiment of the present invention.

[0022] Figure 3 It is a structural diagram of the NTC resistor model shown in the embodiment of the present invention.

[0023] Figure 4 It is a PCB model and a 3D model of components shown in the embodiment of the present invention.

[0024] Figure 5 It is a 3D model of the anemometer housing shown in the embodiment of the present invention.

[0025] Figure 6 It is a 3D model of the electro-thermal coupling model in the ICEPAK software shown in the embodiment of the present invention.

[0026] Figure 7 It is a mesh of the electro-thermal coupling model in the ICEPAK software shown in the embodiment of the present invention.

[0027] Figure 8 The PCB copper layer power density distribution diagram of the electro-thermal coupling model in the SIWAVE software shown in the embodiments of the present invention. Simulation conditions: the NTC resistor current is 0.18 A.

[0028] Figure 9 The copper skin thermal distribution diagram caused by the electrical loss of the PCB copper layer in the electro-thermal coupling model in the SIWAVE software shown in the embodiments of the present invention. Simulation conditions: the NTC resistor current is 0.18 A.

[0029] Figure 10 The local thermal distribution diagram of the NTC resistor in the air-electric-thermal coupling model in the ICEPAK software shown in the embodiments of the present invention. Simulation conditions: the wind speed is 1.7676 m / s; the NTC resistor current is 0.1552 A.

[0030] Figure 11 The PCB thermal distribution diagram of the air-electric-thermal coupling model in the ICEPAK software shown in the embodiments of the present invention. Simulation conditions: the wind speed is 1.7676 m / s; the NTC resistor current is 0.1552 A.

[0031] Figure 12 The fluid distribution diagram of the air-electric-thermal coupling model in the ICEPAK software shown in the embodiments of the present invention. Simulation conditions: the wind speed is 1.7676 m / s; the NTC resistor current is 0.1552 A.

[0032] Figure 13 The calibration fitting curve based on the fluid-electric-thermal coupling simulation method shown in the embodiments of the present invention.

[0033] Figure 14 The comparison between the simulation data and the real wind tunnel test data on the calibration fitting curve shown in the embodiments of the present invention. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] Refer to Figure 1 , a calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation, comprising the following steps:

[0036] S1. Establish an anemometer 3D model, specifically, use the AD20 software to draw and export the PCB model; use the NX12 software to draw and export the 3D models of each component including the NTC resistor model;

[0037] S2. Construct and solve the electro-thermal coupling model of the anemometer through the 3D model of the anemometer. Specifically, import the 3D model of the anemometer into the SIWAVE software; set the initial current and material properties; perform IR-drop electrical simulation calculations by loading excitation conditions on the PCB trace through the SIWAVE software to obtain the PCB power distribution; import the PCB power distribution into the simulation software ICEPAK for PCB board-level thermal simulation to obtain the PCB temperature distribution;

[0038] The i-th electro-thermal joint simulation: Import the PCB temperature distribution of the (i - 1)-th electro-thermal joint simulation into the SIwave software, and perform iterative simulation in the same way as the first electro-thermal joint simulation until the results of the last two electro-thermal joint simulations meet the iterative convergence condition, that is, obtain the electrical loss results of the PCB copper layer in the electro-thermal coupling joint simulation; where i ≥ 2.

[0039] S3. Construct and solve the electro-thermal coupling model of the anemometer in the simulated wind tunnel model. Specifically, use the NX12 software to draw and export the model files of the anemometer housing and the wind tunnel, and add them to the ICEPAK software, and redraw the mesh together with the anemometer PCB and the fan; set the wind speed of the fan in the ICEPAK software; set the PCB power as the electrical loss result of the PCB copper layer after the i-th joint simulation in step S2; perform a new thermal field calculation.

[0040] S4. Determine whether the core temperature of the NTC resistor in the thermal analysis result in step S3 is within the specified range. If so, output the wind speed and the corresponding current data; if not, reset the current and repeat steps S2 and S3. Further, when resetting the current, the current needs to be changed in the direction that makes the core temperature of the NTC resistor closer to the specified operating temperature of the NTC resistor, that is, if the core temperature of the NTC resistor is greater than the specified operating temperature of the NTC resistor, the current should be decreased; conversely, the current should be increased until the absolute value of the difference from the specified operating temperature of the NTC resistor is less than a specified very small range, and then the wind speed and current data at this time can be output.

[0041] S5. Repeat steps S3 and S4 to obtain multiple sets of wind speed and corresponding current data; specifically, set a new wind speed, and repeat steps S3 and S4 to obtain multiple sets of wind speed and corresponding current data required for calibrating the anemometer.

[0042] S6. Obtain the calibration result of the anemometer through function fitting. Use Matlab to perform function fitting of the wind speed and current to complete the calibration of the anemometer.

[0043] Further, the anemometer is a constant-temperature anemometer. The schematic diagram of the NTC resistor detection circuit in this embodiment is as Figure 2As shown. During the working process, the temperature feedback circuit keeps the bridge always balanced, and the NTC resistor is constantly at a certain fixed temperature, that is, the specified working temperature of the NTC resistor. The energy heated by the current inside the resistor can be approximately regarded as the heat taken away by fluid convection heat transfer. Under the condition that other environmental factors such as environmental temperature and humidity remain unchanged, the current in the flow field changes following the flow velocity near the NTC resistor.

[0044] Further, as Figure 4 shown, the 3D model of the anemometer is divided into a PCB model and each component model; the PCB model is exported from the PCB design file in a third-party EDA tool, and the file format is ODB++ file; each component 3D model is exported by NX12 software, and the file format is step file.

[0045] Further, as Figure 3 shown, the structure of the NTC resistor model needs to be fine enough. In the present invention, it is divided into four materials, which are silver, nickel, tin and the special NTC ceramic material in the center from the outside to the inside.

[0046] Further, the conductivity in the material properties is set as a function related to temperature; the excitation conditions include an excitation current source and a voltage source; the initial current is the theoretical current value without considering the influence of temperature on the PCB; the IR-drop electrical simulation calculation is carried out by loading the excitation conditions on the PCB trace through SIwave software, including: obtaining the copper foil electrical loss data of each layer of the PCB.

[0047] Further, importing the PCB power distribution into the simulation software ICEPAK for PCB board-level thermal simulation includes: using SIWAVE to call the ICEPAK solver, setting grid parameters, the power of each component, and the convergence iteration convergence conditions for the electro-thermal coupling, and then performing grid drawing and temperature field analysis after the circuit board is powered on; the SIWAVE software automatically starts the electro-thermal coupling iterative calculation. The iteration convergence conditions include: the power difference between the last two electro-thermal joint simulations is less than the threshold and the temperature difference is less than the threshold.

[0048] Further, perform at least three joint simulations. Let the SIWAVE power result of the i-th simulation be Pi and the ICEPAK temperature result be Ti. At this time, the convergence condition is:

[0049] |Pi - Pi-1| ≤ 0.1W and |Ti - Ti-1| ≤ 0.1°C, where i ≥ 2.

[0050] Further, as Figure 5 and Figure 6As shown, the 3D model in the wind-electricity-thermal coupling model includes: a PCB model, each component model, an anemometer housing model, a wind tunnel model, and a fan; the input power of the wind-electricity-thermal coupling model includes: the PCB copper layer electrical loss result of the electro-thermal coupling co-simulation and the power of each component. The wind tunnel model has a certain length; the orientation of the fan is the direction of the wind tunnel; the NTC resistor extends out of the groove of the anemometer housing, and there is no gap in the groove; one end of the anemometer housing containing the NTC resistor extends into the circular groove of the wind tunnel, and there is no gap in the circular groove.

[0051] Further, the selected wind speed types need to be sufficient to meet the data volume requirements of the anemometer calibration curve.

[0052] The theoretical basis of this simulation-based calibration method: When the anemometer is working, there are four factors affecting the temperature change of the NTC resistor, namely, the self-heating of the resistor caused by the current, the heat convection between the resistor and the moving fluid, the heat conduction between the resistor and the PCB, and the heat radiation between the resistor and the environment. Since the anemometer is working. Since the anemometer is working, the proportions of heat conduction and heat radiation are relatively small. When using the NTC resistor, the heat convection between the resistor and the moving fluid and the self-heating power are mainly considered. According to the heat balance theory, on the premise of ignoring the heat radiation part, the heat generated (working power) by the resistor placed in the flow field should be equal to the heat dissipated by it, that is

[0053] Qt = αS(Tw - Tf),

[0054] In the formula: Qt is the thermal energy carried away by the resistor; α is the convective heat transfer coefficient; S is the contact area between the hot wire and the fluid; Tw is the surface temperature of the resistor; Tf is the temperature of the fluid.

[0055] Combined with King's formula, it can be known that the flow field velocity and direction flowing through the resistor can be obtained from the heat transfer coefficient. For a constant-temperature anemometer, the energy heated by the current inside the resistor can be approximately regarded as the heat carried away by the fluid convection, so as to reach the thermal equilibrium state. When the anemometer is working, the temperature feedback circuit keeps the bridge in balance, and the NTC resistor is always at a fixed working temperature. Therefore, there is a corresponding relationship between the flow velocity of the flow field and the current of the NTC resistor. The fluid-electric-thermal coupling simulation method can be used to verify this relationship, and the accuracy of this method can be verified by experiments.

[0056] Further, the schematic diagram of the NTC resistor detection circuit in this embodiment is as Figure 2 shown, R8 is the NTC resistor, and its specified working temperature is 88.89 °C. The absolute value of the difference between the core temperature of the NTC resistor and 88.89 °C in the specified range does not exceed 0.015 °C. This temperature is calculated according to the resistance value of the NTC resistor and the resistance value and temperature relationship formula in the specification book; the NTC resistor is 4.45 ohms, and this resistance value is measured by a high-precision four-and-a-half-digit instrument.

[0057] It should be understood that the accuracy of the simulation method depends on whether the NTC resistor simulation model is accurate and refined enough. The 3D model of the NTC resistor in this embodiment is drawn by NX12 software. As Figure 3 shown, its materials are silver, nickel, tin on the outer layer and special NTC ceramic material in the center. The thermal conductivities of the first three materials are determined, while the manufacturer usually does not specify the thermal conductivity of the NTC material. Substituting the theoretical data of the thermal conductivity of the NTC material in relevant papers into the actual project is not accurate enough. To obtain a refined NTC model, the thermal conductivity is fine-tuned by comparing with experimental data, and finally a thermal conductivity value consistent with the experimental data is obtained.

[0058] Figure 8 It is the power density distribution diagram of the PCB copper layer when the current of the NTC resistor is 0.18 A in the electro-thermal coupling model of SIWAVE software; Figure 9 It is the copper skin thermal distribution diagram caused by the electrical loss of the PCB copper layer when the current of the NTC resistor is 0.18 A in the electro-thermal coupling model of SIWAVE software. It can be found that when the ambient temperature is 24.9 °C and the components are not considered, the highest temperature of the copper skin near the NTC resistor reaches 35 °C. As a temperature-sensitive component, the NTC resistor is extremely vulnerable to the influence of the ambient temperature, and the influence of the copper skin temperature on the simulation calibration accuracy of the anemometer cannot be ignored. According to the comparison of the simulation results, under this condition, the difference in the core temperature of the NTC resistor before and after introducing the copper skin electrical loss temperature in the wind-electric-thermal coupling model is 0.561 °C.

[0059] Figure 7 It is the grid of the wind-electric-thermal coupling model in ICEPAK (the number of grids is 3.07 million); Figures 10 - 12 It is the simulation diagram of the wind-electric-thermal coupling model in ICEPAK when the wind speed is 1.7676 m / s and the current of the NTC resistor is 0.1552 A; Figure 10 It is the local thermal distribution diagram of the NTC resistor; Figure 11 It is the PCB thermal distribution diagram; Figure 12 It is the fluid distribution diagram of the wind-electric-thermal coupling model.

[0060] Figure 13 It is the function fitting curve using Matlab based on the following five groups of simulation data:

[0061]

[0062]

[0063] That is, when the ambient temperature is 25 °C, the functional relationship between the wind speed and the current is fitted by Matlab as:

[0064]

[0065] Where y is the wind speed (m / s) and x is the current (A) flowing through the NTC resistor R6. Using this relationship, the wind speed can be accurately measured by the microcontroller through software filtering and data processing.

[0066] To verify the reliability of the simulation-based calibration method, a real wind tunnel experiment was conducted for wind speed calibration, and the following five groups of measured current data were obtained under the same wind speed conditions; the differences between the wind speeds calculated by substituting the measured current into the Fit curve and the measured wind speeds are shown below, with a maximum not exceeding 1 m / s;

[0067]

[0068] The comparison of the simulation data and the experimental data on the fitting curve is as Figure 14 shown. It can be found that the simulation data is close to the experimental data, and the calibration method of the anemometer based on fluid-electric-thermal coupling simulation of the present invention has high accuracy, and the wind speed range is not limited.

[0069] The number of devices and the processing scale described here are used to simplify the description of the present invention, and the application, modification, and variation of the present invention are obvious to those skilled in the art. Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated and described examples here.

Claims

1. A calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation, characterized in that, It includes the following steps: S1. Establish a 3D model of the anemometer; S2. Construct and solve the electro-thermal coupling model of the anemometer through the 3D model of the anemometer; S3. Construct and solve the electro-thermal coupling model of the anemometer in the simulated wind tunnel model; S4. Judge whether the core temperature of the NTC resistor in the thermal analysis result in step S3 is within the specified range. If so, output the wind speed and corresponding current data; if not, reset the current and repeat steps S2 and S3; S5. Repeat steps S3 and S4 to obtain multiple groups of wind speed and corresponding current data; S6. Obtain the calibration result of the anemometer through function fitting, and use Matlab to perform function fitting of wind speed and current to complete the calibration of the anemometer.

2. The calibration method of a constant temperature anemometer based on fluid-electric-thermal coupling simulation according to claim 1, wherein The specific content of step S2 is to import the 3D model of the anemometer into the SIWAVE software; set the initial current and material properties; perform IR-drop electrical simulation calculation by loading excitation conditions on the PCB trace through the SIWAVE software to obtain the PCB power distribution; import the PCB power distribution into the simulation software ICEPAK for PCB board-level thermal simulation to obtain the PCB temperature distribution; The i-th electro-thermal co-simulation: Import the PCB temperature distribution of the (i - 1)-th electro-thermal co-simulation into the SIwave software, and perform iterative simulation in the same way as the first electro-thermal co-simulation until the results of the last two electro-thermal co-simulations meet the iterative convergence condition, that is, obtain the electro-thermal coupling co-simulation result of the PCB copper layer electrical loss; where i ≥ 2.

3. A calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation according to claim 1, characterized in that, In step S3, use the NX12 software to draw and export the model files of the anemometer housing and the wind tunnel, and add them to the ICEPAK software to redraw the mesh together with the anemometer PCB and the fan; Set the wind speed of the fan in the ICEPAK software; Set the PCB power to the electro-thermal coupling co-simulation result of the PCB copper layer in the i-th co-simulation in step S2; re-perform the thermal field calculation.

4. A calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation according to claim 2, characterized in that The conductivity in the material properties is set as a function related to temperature; the excitation conditions include an excitation current source and a voltage source; the initial current is the theoretical current value without considering the influence of temperature on the PCB; The performing IR-drop electrical simulation calculation by loading excitation conditions on the PCB trace through the SIwave software includes: obtaining the copper foil electrical loss data of each layer of the PCB.

5. A calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation according to claim 2, characterized in that, The importing the PCB power distribution into the simulation software ICEPAK for PCB board-level thermal simulation includes: Using SIWAVE to call the ICEPAK solver, setting the grid parameters, the power of each component, and the electro-thermal coupling convergence iteration convergence condition, and then performing grid drawing and temperature field analysis after the circuit board is powered on; the SIWAVE software automatically starts electro-thermal coupling iterative calculation.

6. The calibration method of a constant-temperature anemometer based on fluid-electric-thermal coupling simulation according to claim 2, wherein The iterative convergence condition includes: the power difference between the last two electro-thermal co-simulations is less than the threshold and the temperature difference is less than the threshold.

7. A calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation according to claim 1, characterized in that, Resetting the current requires changing the current in the direction that makes the core temperature of the NTC resistor closer to the specified operating temperature of the NTC resistor. That is, if the core temperature of the NTC resistor is greater than the specified operating temperature of the NTC resistor, the current should be decreased; conversely, the current should be increased until the absolute value of the difference from the specified operating temperature of the NTC resistor is less than a specified small range, and then the wind speed and current data at this time can be output.

8. A calibration method for a constant-temperature anemometer based on fluid-electric-thermal coupling simulation according to claim 1, characterized in that At least three co-simulations are performed. Let the SIWAVE power result of the i-th simulation be Pi and the ICEPAK temperature result be Ti. The convergence condition at this time is: |Pi - Pi-1| ≤ 0.1 W and |Ti - Ti-1| ≤ 0.1 °C, where i ≥ 2.

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