Low-pressure wind field simulation system and method based on submerged jet

Abstract

The invention provides a sinking jet-based low-pressure wind field simulation system and method, and the system comprises a space environment simulation container, a simulation air duct disposed in the space environment simulation container, a plurality of sensors to be calibrated, a moving mechanism, an air duct air inlet pipeline, an air source, a flow control assembly, and a pressure control assembly. And the moving mechanism is used for driving the plurality of sensors to be calibrated to move into the submerged jet range so as to calibrate the wind speed. According to the invention, multiple sensors to be calibrated can be calibrated at the same time, a low-pressure simulation air duct with stable sinking jet can be accurately formed, and the problems of large nozzle speed error and unstable wind field in calibration of the air duct are solved.

Description

Technical Field

[0001] This application relates to the field of environmental testing technology, and more specifically, to a low-pressure wind field simulation system and method based on submerged jets. Background Technology

[0002] To validate deep-space probes and high-altitude drones operating under low-pressure conditions, such as in ground tests of Mars probes and stratospheric drones, it is necessary to simulate the convective environment they operate in, specifically simulating a convective environment at -80°C and approximately 1000 kPa. However, current methods for measuring wind speed, including thermal, ultrasonic, and dynamic pressure measurements, are all affected by extremely low pressure, often resulting in weak signals and susceptibility to interference. Specialized low-pressure wind speed sensors also often require recalibration under these conditions. Existing systems often present difficulties in use and error assessment. Specifically, errors in existing systems tend to accumulate over time. For example, in rotating anemometer calibration systems, as calibration progresses, air gradually flows with the airflow, increasing the original flow field velocity and decreasing the velocity difference between the rotating arm and the flow field, leading to a gradually increasing calibration error. This error cannot be measured using current methods and is therefore difficult to assess. Furthermore, the Reynolds number is extremely low under low pressure, often resulting in laminar flow. Therefore, calibration methods using air ducts often lead to boundary layer separation, making it difficult to achieve uniform wind speed distribution at the outlet. Compared to the rotary method, the parameters of the open duct method are difficult to control, and various devices are often required to be installed on the outside of the container for temperature and flow control, making the required system extremely complex.

[0003] Therefore, it is necessary to provide a new low-pressure wind field simulation system and method based on submerged jets to solve one of the aforementioned technical problems. Summary of the Invention

[0004] The purpose of this application is to provide a low-pressure wind field simulation system and method based on submerged jets, which can solve at least one of the aforementioned technical problems. The specific solution is as follows:

[0005] According to a specific embodiment of this application, this application provides a low-pressure wind field simulation system based on submerged jets, comprising: a space environment simulation container with a built-in simulated wind duct; multiple sensors to be calibrated, arranged near the nozzles of the simulated wind duct; a moving mechanism connected to the multiple sensors to be calibrated, used to drive the multiple sensors to be calibrated to move within the submerged jet range formed by the simulated wind duct for wind speed calibration; a wind duct inlet pipe connected to the simulated wind duct; a gas source for supplying gas to the simulated wind duct through the wind duct inlet pipe; a flow control component located between the gas source and the wind duct inlet pipe for controlling the inlet gas flow rate of the simulated wind duct; and a pressure control component connected to the space environment simulation container for controlling the pressure inside the space environment simulation container.

[0006] According to a specific embodiment of this application, this application also provides a low-pressure wind field simulation method based on submerged jets, which uses the low-pressure wind field simulation system based on submerged jets described in this application, including: determining the Reynolds number under the current calibration conditions based on different wind ducts; calculating the inlet gas flow rate required for calibration based on the determined Reynolds number range and the selected wind duct; selecting a suitable flow controller based on the calculated inlet gas flow rate required for calibration, and actively controlling the pressure inside the space environment simulation container until the environmental parameters of the simulated wind duct stabilize, so as to form a submerged jet at the nozzle of the simulated wind duct; within the range of the submerged jet formed by the nozzle of the simulated wind duct, collecting signals from multiple sensors to be calibrated multiple times for multi-point testing, and performing error calculation to determine valid data; and determining the calibration matrix of the multiple sensors to be calibrated based on the determined valid data.

[0007] According to a specific embodiment of this application, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the low-pressure wind field simulation method based on submerged jet as described in any of the preceding claims.

[0008] According to a specific embodiment of this application, this application also provides an electronic device, including: one or more processors; and a storage device for storing one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement the low-pressure wind field simulation method based on submerged jet as described in any of the preceding claims.

[0009] Compared with the prior art, the above-described solutions of this application have at least the following beneficial effects:

[0010] The low-pressure wind field simulation system of this application can simulate a more stable submerged jet range in the wind duct, thereby obtaining an extremely uniform wind field. By simultaneously moving multiple sensors to be calibrated in one dimension within the uniform area of ​​the submerged jet range formed by the wind duct outlet to collect relevant data, calibration errors can be effectively reduced. By simultaneously calibrating multiple sensors to be calibrated within a specified area formed by the wind duct nozzle, the calibration workload of the sensors can be reduced more efficiently.

[0011] Furthermore, by controlling and adjusting the temperature and flow rate of the incoming gas, the speed and temperature controllability of the simulated wind field can be improved. Attached Figure Description

[0012] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0013] Figure 1 This is a schematic diagram of the low-pressure wind field simulation system based on submerged jet according to an embodiment of this application;

[0014] Figure 2 This is a partial structural diagram of the simulated wind duct and simulated wind duct nozzle in the low-pressure wind field simulation system based on submerged jet according to an embodiment of this application.

[0015] Figure 3 This is a schematic diagram of the submerged jet range formed by the simulated wind duct of the low-pressure wind field simulation system based on submerged jet according to an embodiment of this application.

[0016] Figure 4 This is a flowchart illustrating the low-pressure wind field simulation method based on submerged jets according to an embodiment of this application.

[0017] Figure 5 This is a schematic diagram of the velocity nozzle of the simulated air duct nozzle of the low-pressure wind field simulation system based on submerged jet according to an embodiment of this application.

[0018] Figure 6 This is a schematic diagram of the electronic device structure shown in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0021] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0022] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of this application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, first may also be referred to as second without departing from the scope of the embodiments of this application, and similarly, second may also be referred to as first.

[0023] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0024] This application provides a low-pressure wind field simulation system and method based on submerged jet. The low-pressure wind field simulation system includes: a space environment simulation container, a simulated air duct built into the space environment simulation container, multiple calibration sensors deployed near the nozzle of the simulated air duct, a moving mechanism, an air inlet pipe for the air duct, an air source, a flow control component, and a pressure control component. The moving mechanism is used to drive the multiple sensors to be calibrated to move within the submerged jet range formed by the simulated air duct for wind speed calibration. Through the simulated air duct in this low-pressure wind field simulation system, a more stable submerged jet range can be formed, thereby obtaining an extremely uniform wind field. By simultaneously moving multiple sensors to be calibrated one-dimensionally within the uniform area of ​​the submerged jet range formed by the air duct outlet to collect relevant data, calibration errors can be effectively reduced.

[0025] It should be noted that this application uses the simulated pressure difference inside and outside the air duct as the wind speed driving method, and the flow meter on the outside of the space environment simulation container as the mass flow rate, i.e., the wind speed reference. It employs the simultaneous movement of multiple sensors to be calibrated (e.g., hot-wire anemometers) to actively collect and test the wind speed signal distribution of the simulated air duct nozzle (sometimes referred to as the "air duct nozzle" in this application) multiple times. The wind speed at the air duct nozzle is calculated and corrected to accurately calibrate the sensors to be calibrated, thereby solving the problem of difficulty in assessing the velocity error of the calibrated air duct nozzle. Furthermore, the method in this application has wide applications, particularly suitable for scenarios such as Mars rovers and low-speed stratospheric vehicles. In the ground verification of Mars probes and stratospheric spacecraft, it is usually necessary to simulate the extreme convective environment faced by the probes and spacecraft. Before the ground simulation test, the sensors to be calibrated can be calibrated more accurately and effectively, so that the calibrated wind speed sensors can effectively measure the wind speed in the low-pressure environment (700Pa in the Martian environment and 5500Pa in the typical 20km stratosphere environment) in the ground simulation test. They can accurately form a low-pressure simulated wind field with a stable submerged jet, thereby solving the problems of large velocity error and unstable wind field in the calibration of the wind duct nozzle.

[0026] The following is in conjunction with the appendix Figures 1 to 3 Detailed description of optional embodiments of the system in this application.

[0027] like Figure 1As shown, the low-pressure wind field simulation system based on submerged jet of this application includes a space environment simulation container 101, a simulated wind duct built into the space environment simulation container 101, multiple sensors to be calibrated, a moving mechanism connected to the multiple sensors to be calibrated, a wind duct inlet pipe connected to the simulated wind duct, an air source 401, a flow control component 405 located between the air source 401 and the wind duct inlet pipe, and a pressure control component connected to the space environment simulation container 101. The moving mechanism includes a moving block and a stepper motor for driving the moving block to move. The wind duct inlet pipe includes an air inlet 201 located outside the simulated wind duct and inside the space environment simulation container 101, and an air outlet 202 located inside the simulated wind duct. The pressure control component includes multiple components.

[0028] A stepper motor is used to drive a moving block to move towards the stepper motor until the moving block contacts a limit switch, thus establishing a zero-position reference for the movement (i.e., the position of the sensor to be calibrated returns to zero). The movement of the moving block is controlled to move multiple sensors to be calibrated within the submerged jet range. By controlling the vent valve and the air inlet valve in the air duct, and adjusting the bridge resistance, different calibration conditions of the multiple sensors to be calibrated are tested.

[0029] Specifically, the space environment simulation container 101 is a vacuum container, and heat sinks 102 are symmetrically arranged on the upper and lower sides inside the space environment simulation container 101. The pressure control components connected to the space environment simulation container 101 include an air extraction pipeline 103, a heat sink 104, a first opening valve 105, a second opening valve 106, an adjusting air intake pipeline 107, and a vacuum pump 108.

[0030] Optionally, the space environment simulation container 101 is used to simulate low-temperature (e.g., temperature range of -150℃ to 20℃) and low-pressure (e.g., pressure range of 100Pa to 101325Pa) environments, and is a horizontal cylindrical large vacuum container. A heat sink 102 is installed inside the space environment simulation container 101, uniformly distributed along the circumference of the container, and its temperature can be set between -196℃ and 0℃, providing the capability for low-temperature environment simulation.

[0031] Furthermore, the gas source 401 is used to supply the gas to be transported to the simulated air duct. The gas source 401 is connected to the pressure reducing valve 402 to reduce the pressure of the gas to be transported. A first pressure sensor 403 and a first temperature sensor 404 are provided downstream of the pressure reducing valve 402. The first pressure sensor 403 is used to monitor the pressure of the gas to be transported after pressure reduction, and the first temperature sensor 404 is used to monitor the temperature of the gas to be transported entering the flow control component 405.

[0032] Next, downstream of the first temperature sensor 404, a flow control component 405, a turbine expander 406, and an insulated pipe 408 are provided. The flow control component 405 is used to precisely control the gas flow rate to achieve a specified volumetric flow rate, which serves as a wind speed reference source. The turbine expander 406 is used to expand and cool the gas to be delivered into the simulated air duct, thereby reducing the gas temperature and pressure. The turbine expander allows the gas to expand adiabatically under pressure difference for a first cooling process. The insulated pipe 407 prevents the cooled gas from exchanging heat with the outside environment. The insulated pipe 407 is used for insulation, and the insulated pipe 407 is connected to the inlet pipe 409 in the space environment simulation container 101 by the through-wall flange 408. The inlet pipe 409 is a non-insulated pipe. The inlet pipe 409 includes a metal hose and is located above the heat sink 102 (i.e., the lower heat sink). The inlet pipe can exchange heat with the heat sink 102 in the space environment simulation container for a second cooling process. The metal hose makes the temperature of the gas inside it closer to the temperature of the gas inside the space environment simulation container 101 (i.e., regardless of whether the gas temperature is higher or lower than the temperature of the gas inside the space environment simulation container 101, the gas temperature in the inlet pipe 409 can be close to the temperature of the gas inside the space environment simulation container 101 by the heat transfer effect of the heat sink). To further ensure the temperature of the gas entering the simulated air duct, a second temperature sensor 410 is installed upstream of the simulated air duct. The second temperature sensor 410 is used to measure the temperature of the gas after heat exchange with the heat sink 102. Since the temperature of the heat sink is lower than the gas temperature inside the space environment simulation container 101, it is only necessary to consider heating the gas. For example, the gas can be heated using a heater 411 to bring the gas temperature to the expected temperature, thereby achieving precise temperature control.

[0033] Optionally, the programmable power supply 418 can control the power of the heater 411 to control the temperature of the gas by adjusting its output. The heating cable 416 is connected to the heater 411 via a through-wall airtight electrical connector 417.

[0034] Furthermore, before entering the simulated air duct, the gas temperature is directly measured using a third temperature sensor 412, and the exhaust valve 413 or the air duct inlet valve 414 is controlled to perform corresponding operations. Specifically, when the gas temperature measured by the third temperature sensor 412 differs from the expected temperature, the exhaust valve 413 is opened to discharge the gas from the exhaust pipe 415. Conversely, when the gas temperature measured by the third temperature sensor 412 equals the expected temperature, the air duct inlet valve 414 is opened to introduce the gas into the simulated air duct, preventing the impact of temperature discrepancies on the simulated air duct.

[0035] It should be noted that in this application, the upstream side and downstream side are defined by the direction of gas delivery from the gas source to the simulated air duct, with the side closer to the gas source being the upstream side and the side closer to the simulated air duct being the downstream side.

[0036] like Figure 2 As shown, the simulated air duct is built into the space environment simulation container 101. The simulated air duct sequentially includes an air inlet 201, an air outlet 202, a baffle 203, a duct stabilization section 204, a rectifier 205, a first turbulence reduction net 206, a second turbulence reduction net 207, a converging section 208, and a submerged jet nozzle 209. The air outlet 202 introduces gas with adjusted temperature and flow rate into the simulated air duct. Under the action of the baffle 203, the gas is dispersed, and under the action of the rectifier 205, the first turbulence reduction net 206, and the second turbulence reduction net 207 in the duct stabilization section 204, a preliminary uniform gas flow is formed. The gas is then accelerated under the action of the converging section 208, forming a high-quality flow. The converging section 208 is, for example, a hypercubic curve configuration.

[0037] from Figure 2 As can be seen from the diagram, multiple sensors to be calibrated are arranged near the submerged jet nozzle 209. These sensors include a first thermal anemometer 3011, a second thermal anemometer 3012, and a third thermal anemometer 3013. The first thermal anemometer 3011, the second thermal anemometer 3012, and the third thermal anemometer 3013 are connected to the anemometer bridge 305 using thermal anemometer probe cables.

[0038] Specifically, the thermal anemometer cable includes an internal compensation cable 3021 located inside the space environment simulation container 101 and an external compensation cable 3022 located outside the space environment simulation container 101. The internal compensation cable 3031 and the external compensation cable 3032 are connected by a through-wall airtight electrical connector 304. The anemometer bridge 305 is a 1:1 bridge. For example, the ratio of the fixed resistors of the bridge arms (i.e., R1:R2) is 1:1, where R3 represents the variable resistor used to set the expected operating temperature of the hot-wire sensor (i.e., HWprobe). The HW bridge arm and the R3 bridge arm correspond to the thermal anemometer cable and the thermal anemometer compensation cable, respectively. By ensuring that the thermal anemometer cable and the thermal anemometer compensation cable are led out in the same environment, they can be ensured to be affected by the same temperature, thereby compensating for the influence of the thermal anemometer cable at low temperatures and effectively improving the measurement and calibration accuracy.

[0039] like Figure 2As shown, the first thermal anemometer 3011, the second thermal anemometer 3012, and the third thermal anemometer 3013 are connected to a moving mechanism (specifically including an optical axis 504, a lead screw 505, and a moving block 501). The moving mechanism is connected to a stepper motor 508, which drives the moving mechanism to move the first thermal anemometer 3011, the second thermal anemometer 3012, and the third thermal anemometer 3013. The first thermal anemometer 3011, the second thermal anemometer 3012, and the third thermal anemometer 3013 are fixed to a sensor mounting base 502 using fixing bolts 503. The sensor mounting base 502 is detachably fixed to the moving block 501, so that when the moving block 501 moves, it can move the first thermal anemometer 3011, the second thermal anemometer 3012, and the third thermal anemometer 3013 along the optical axis 504. The moving mechanism is connected to the stepper motor 508 using a coupling 507. The first fixing block 5061 and the second fixing block 5062 respectively fix the two ends (first end and second end) of the optical shaft 504 and the lead screw 505. The second fixing block 5062 fixes the second end of the optical shaft 504 and the lead screw 505 to the coupling 507. The optical shaft 504 cooperates with a linear bearing, and the lead screw 505 cooperates with a nut, so that when the lead screw 505 rotates, the moving block 501 can move from the first end to the second end, or from the second end to the first end.

[0040] Optionally, a limit switch 509 is also provided at the second end of the optical axis 504. The limit switch 509 is used to limit the position of the moving block 501 near the second end of the optical axis 504, which can prevent out-of-tolerance or prevent motion interference. By controlling the moving block 501 to move left and right (i.e., from the first end to the second end, or from the second end to the first end), multiple sensors to be calibrated can be calibrated simultaneously within a specified area formed by the air duct nozzle, which can more efficiently reduce the workload of sensor calibration.

[0041] Specifically, the sensor mounting base 502 is used to fix sensors of different diameters to be calibrated. The sensor mounting base 502 includes an adjustable slot for inserting sensors of different diameters to be calibrated, for example, by fixing the sensors to be calibrated using fixing bolts 503. The sensor to be calibrated is a thermal anemometer.

[0042] The submerged jet range formed by the simulated wind duct 208 of the low-pressure wind field simulation system of this application, such as Figure 3 The wind field stability region shown is 210. From Figure 2As can be seen, the outlet diameter of the simulated wind duct 208 is D, and the submerged jet range formed by the simulated wind duct 208 is a cone with a length of 5×D along the wind duct direction. Multiple sensors to be calibrated can obtain an extremely uniform wind field within the submerged jet range, thus forming a more stable submerged jet range. By simultaneously moving multiple sensors to be calibrated one-dimensionally within the uniform area of ​​the submerged jet range formed by the wind duct outlet to collect relevant data, calibration errors can be effectively reduced. Furthermore, by simultaneously calibrating multiple sensors within a designated area formed by the wind duct nozzle, the calibration workload of the sensors can be reduced more efficiently. In addition, the temperature and flow rate of the incoming gas can be adjusted by regulating the gas supply, improving the controllability of the simulated wind field's speed and temperature.

[0043] Compared with existing technologies, the low-pressure wind field simulation system of this application can form a more stable submerged jet range in the simulated wind duct, thereby obtaining an extremely uniform wind field. By simultaneously moving multiple sensors to be calibrated one-dimensionally within the uniform area of ​​the submerged jet range formed by the wind duct outlet to collect relevant data, calibration errors can be effectively reduced. By simultaneously calibrating multiple sensors to be calibrated within a designated area formed by the wind duct nozzle, the calibration workload of the sensors can be reduced more efficiently. In addition, the temperature and flow rate of the incoming gas can be adjusted by regulating the gas supply, thereby improving the controllability of the speed and temperature of the simulated wind field.

[0044] The following is in conjunction with the appendix Figure 3 , Figure 4 and Figure 5 Detailed description of optional embodiments of the method of this application.

[0045] This application also provides a method for simulating low-pressure wind fields based on submerged jets.

[0046] like Figure 4 As shown, in step S101, the Reynolds number under the current calibration condition is determined based on different air ducts.

[0047] The environmental parameters under the current calibration conditions are measured and adjusted. These environmental parameters include target temperature, target pressure, target wind speed, and gas composition, including carbon dioxide, nitrogen, etc.

[0048] The nozzle Reynolds number is calculated for each calibration condition to determine the Reynolds number under the current calibration condition, that is, to determine the minimum Reynolds number to be simulated under the current condition.

[0049]

[0050] Where Re represents the minimum Reynolds number to be simulated under the current operating conditions; D is the diameter of the nozzle in the simulated air duct; μ is the dynamic viscosity of the gas, which can be obtained from a table based on the target temperature; Vave T represents the expected average velocity of the gas exiting the nozzle of the simulated air duct under the current calibration conditions; env and P env These represent the target temperature (specifically, Kelvin temperature) and target pressure, respectively; R is the gas constant corresponding to different gases. For example, it is 297 for nitrogen and 189 for carbon dioxide. Based on the above expressions, the Reynolds number of the duct nozzle under various calibration conditions can be calculated, thereby obtaining the Reynolds number range to be simulated. Furthermore, considering the requirements of different calibration conditions, Reynolds numbers are calculated for different duct configurations.

[0051] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.

[0052] Next, in step S102, the required inlet gas flow rate is calculated based on the determined Reynolds number range and the selected duct.

[0053] Specifically, the tapering section of the air duct is selected according to selection rules, which include not changing the tapering section of the simulated air duct during the same calibration process, ensuring that the Reynolds number under each calibration condition is greater than a specified value (the specified value is, for example, 5000), and simultaneously minimizing the size of the tapering section of the simulated air duct.

[0054] For example, the tapering section of the simulated air duct can be selected as a bicubic curve configuration.

[0055] Figure 5 This is a schematic diagram of the nozzle velocity distribution obtained by applying the low-pressure wind field simulation method of this application.

[0056] like Figure 5 As shown, 606 represents the wind speed distribution at Re=15000, 605 at Re=8000, 604 at Re=4000, 603 at Re=2000, 602 at Re=1000, 601 at Re=500, 607 represents the geometric range of the entire duct nozzle, and 608 represents the stable wind speed region at Reynolds number Re=500. Figure 5 As can be seen, when the Reynolds number is low, the wind velocity at the duct nozzle often exhibits a large non-uniform region. Therefore, when selecting the corresponding duct nozzle, a Reynolds number (Re) greater than 5000 is chosen to maximize the submerged jet range (i.e., the stable range or wind field stable region) of the duct nozzle. Figure 3 As shown, it is a cone with a base diameter D and a height of 5D or more, which is the stable wind field region. The sensor to be calibrated can obtain an extremely uniform wind field within the stable wind field region.

[0057] After selecting the tapering section of the simulated air duct, the air velocity at the nozzle of the simulated air duct is corrected:

[0058] V ave =V Tar / a

[0059] Among them, V ave V represents the expected wind speed after correction based on the duct structure and the outlet Reynolds number; Tar This represents the expected wind speed value near the wind speed sensor; 'a' is a function value related to the duct structure and the outlet Reynolds number, i.e., a calibration parameter. For each specific duct, 'a' is obtained, for example, through CFD simulation calculations.

[0060] Specifically, when the Reynolds number Re∈[5000,50000), the calibration parameters satisfy the following expression:

[0061] a=c5Re 5 +c4Re 4 +c3Re 3 +c2Re 2 +c1Re 1 +c0;

[0062] Where 'a' is a function value related to the duct structure and outlet Reynolds number, i.e., a calibration parameter, and the value of 'a' ranges from 1.0 to 1.4; c0 to c5 represent the first, second, third, fourth, fifth, and sixth fitting parameters obtained by least squares fitting, respectively.

[0063] Specifically, among the first, second, third, fourth, fifth, and sixth fitting parameters, the first fitting parameter is the largest.

[0064] Optionally, after fitting, c0 takes the value of 1.0 to 1.3, while c1, c2, c3, c4, and c5 are all much smaller than 1, for example, less than 10. -4 .

[0065] When the Reynolds number is greater than 50,000, a equals 1.

[0066] In one specific implementation, the first, second, third, fourth, fifth, and sixth fitting parameters are obtained by fitting CFD calculation results. For example, about 10 data points are randomly selected between 5000 and 50000 to establish a duct simulation model. CFD simulation calculations are performed on the expected working conditions, and the V value for each calibration working condition is obtained. Tar / V ave , where V TarV represents the wind speed at the exact center of the simulated duct outlet, such as a vector [1.5, 1, 1.5, 2, ..., 15]. ave The vector represents the average nozzle velocity calculated based on the inlet flow rate, such as [1.3, 0.9, 1.4, 1.9, ... 14.6]. The first, second, third, fourth, fifth, and sixth fitting parameters are obtained by fitting two sets of vectors using the least squares method.

[0067] Using the above calculation method, the expected average wind speed can be obtained quickly with very little computation, thereby correcting the impact of uneven outlet speed distribution.

[0068] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.

[0069] Before calibration, the environmental parameters (specifically temperature and pressure) inside the space environment simulation container are adjusted until all parameters stabilize. The adjustment of environmental parameters will be explained in detail below in conjunction with step S103.

[0070] Next, in step S103, based on the calculated required inlet gas flow rate, a suitable flow controller is selected, and the pressure inside the space environment simulation container is actively controlled until the environmental parameters of the simulated air duct are stable, so as to form a submerged jet at the nozzle of the simulated air duct.

[0071] Specifically, read the following environmental parameters under the current calibration conditions: temperature, pressure, and wind speed data.

[0072] Calculate the nozzle volumetric flow rate of the current simulated air duct nozzle, based on the environmental parameters under the current calibration conditions.

[0073] Based on the current measurements from the pressure and temperature sensors, recalculate the expected flow rate of the flow controller, i.e., the inlet gas flow rate (or the inlet gas flow rate required for calibration).

[0074] The expected flow rate of the flow controller, i.e., the inlet gas flow rate (or the inlet gas flow rate required for calibration), is calculated using the following expression:

[0075]

[0076] in, T represents the expected flow rate of the flow controller; 测 and P 测 These represent the Kelvin temperature and pressure of the gas before it enters the flow meter, respectively. This indicates the pressure under the current calibration conditions; This indicates the Kelvin temperature under the current calibration conditions; This represents the expected average wind speed of the gas exiting the nozzle of the simulated air duct under the current calibration conditions; D represents the diameter of the air duct nozzle.

[0077] Based on the calculated and calibrated required inlet gas flow rate, a suitable flow controller is selected, and the pressure inside the space environment simulation container is actively controlled until the environmental parameters of the simulated air duct are stable, so as to form a submerged jet at the nozzle of the simulated air duct, that is, to form a submerged jet range.

[0078] In one specific implementation, an inlet flow controller is set according to the calculated inlet gas flow rate. That is, the expected flow rate of the simulated environment is calculated according to the calculated inlet gas flow rate, the flow controller with the best matching range is selected, set to the calculated inlet gas flow rate, and the other flow controllers are turned off to ensure that the flow rate through the flow controller group is the expected flow rate.

[0079] Adjusting the environmental parameters within the space environment simulation container also includes temperature control. Specifically, temperature control is activated after the test begins, and the temperature is adjusted to the expected temperature via the heater. Specifically, the temperature control function of heater 411 is activated to control the temperature. Based on the gas temperature measured by the second temperature sensor 410 and combined with the temperature measured by the third sensor 412, the gas to be transported (i.e., to be transported to the simulated air duct) is further heated by feedback.

[0080] Adjusting environmental parameters within the space environment simulation container also includes pressure control. For example, when the pressure inside the space environment simulation container exceeds a specific value (e.g., the specific value is the expected pressure ±5 Pa), outlet pressure control is activated. That is, based on the calculated inlet gas flow rate, the pressure inside the environment simulation container is actively controlled. This is achieved by adjusting the opening of the first opening valve 105 and the second opening valve 106 (e.g., using PID control for automatic adjustment).

[0081] Specifically, when the pumping volume is large (e.g., greater than 0.5 times the pumping capacity), the flow resistance between the space environment simulation container 101 and the vacuum pump 108 is changed by adjusting the opening of the first opening valve 105, thereby changing the pumping volume of the vacuum pump 108 and achieving dynamic pressure control within the space environment simulation container 101. When the pumping volume is small (less than 0.5 times the pumping capacity) and the first opening valve 105 is opened to its maximum, the amount of gas entering from the inlet pipe 107 is changed by adjusting the opening of the second opening valve 106, thereby regulating the pressure within the space environment simulation container 101. That is, without changing the flow resistance between the space environment simulation container 101 and the vacuum pump 108, the proportion of the total pumping volume of the vacuum pump 108 within the space environment simulation container 101 is changed, thereby achieving dynamic pressure control within the space environment simulation container 101.

[0082] When all the above environmental parameters are stable, that is, when the temperature, flow rate and pressure of the simulated air duct are stable, close the vent valve and open the inlet valve. That is, close the vent valve 413 and open the air duct inlet valve 414, so that the flow with stable temperature, pressure and wind speed enters the simulated air duct, forming a submerged jet range at the air duct nozzle. This can effectively form a stable submerged jet range for the calibration of the sensor to be calibrated.

[0083] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.

[0084] Next, in step S104, within the range of the formed submerged jet, multiple signals are collected from multiple sensors to be calibrated for multi-point testing, and error calculation is performed to determine the valid data.

[0085] Within the submerged jet range formed in step S103, signals are collected multiple times from multiple sensors to be calibrated for multi-point testing, and error calculation is performed to determine valid data.

[0086] Before calibration begins, it is determined whether the environmental parameters within the space environment simulation container have stabilized. If all environmental parameters within the space environment simulation container are confirmed to be stable, calibration of the sensor to be calibrated begins. If one or more environmental parameters within the space environment simulation container are found to be unstable, environmental parameter adjustments are performed until all environmental parameters are stable before calibration of the sensor to be calibrated begins. This allows for the establishment of stable flow patterns in terms of temperature, pressure, and wind speed within the simulated airflow duct of the space environment simulation container.

[0087] To begin the calibration process, the position of the sensor to be calibrated is returned to zero. This is achieved by rotating stepper motor 508 (e.g., in reverse or forward) to drive moving block 501 in the direction of stepper motor 508 until moving block 501 contacts limit switch 509. This establishes the zero-position reference for the movement, meaning the position of the sensor to be calibrated is returned to zero. See [link to documentation] for details. Figure 1 and Figure 2 .

[0088] Next, the moving block is controlled to move to move multiple sensors to be calibrated to the submerged jet range (specifically to the wind field stable region 210, sometimes also called the "nozzle velocity stable region 210"), so as to control the exhaust valve and the air duct inlet valve, adjust the bridge resistance value, and test the multiple sensors to be calibrated under different calibration conditions.

[0089] Specifically, this includes high-speed and low-speed tests. Since low air pressure significantly alters convective heat transfer characteristics, the signal range must be tested to prevent issues such as excessively low low-speed signals or high-speed signal saturation. Specifically, low-speed tests (i.e., opening and closing the exhaust valve 413 and opening the duct inlet valve 414) simulate the wind speed V at the center of the duct outlet. Tar Set to low wind speed, calculate the expected average wind speed V of the gas exiting the nozzle of the simulated air duct. ave and the expected flow of the flow controller The flow controller is used for control, while the pressure and temperature inside the simulated space environment container 101 are stabilized. This allows for testing of the bridge voltage signal output at low wind speeds. Subsequently, the wind speed is adjusted to a high wind speed, and the bridge resistance is adjusted to test the signal. The test should cover all calibration conditions. When the output signal is too small at low wind speeds (the signal change is too small to be measured), or when the signal is saturated at high wind speeds (the signal reaches its maximum value of 5V before reaching high wind speed), the resistance configuration of the bridge circuit needs to be adjusted appropriately to optimize the measurement sensitivity.

[0090] It should be noted that in this example, the high wind speed and low wind speed are related to the wind speed to be calibrated. For example, when the wind speed to be calibrated is 10m / s to 100m / s, the high wind speed is 100m / s and the low wind speed is 10m / s.

[0091] By adjusting the CTA bridge and based on the results of the unventilated wind speed test, the operating resistance value of the CTA bridge (i.e., the resistance value of the CTA bridge determines the expected operating temperature of the wind speed probe) is determined and set. The expected operating temperature refers to the ambient temperature of the sensor to be calibrated, which is increased or decreased by a specific degree (e.g., 100℃~200℃).

[0092] In one specific implementation, full-range calibration is performed, that is, formal calibration begins, and the signal (e.g., output voltage) output by the sensor to be calibrated under each calibration condition is tested and recorded.

[0093] For each calibration condition (i.e., each specific temperature T) env Pressure P env Wind speed V Tar Under the combination of wind speeds in the stable region 210 (see details) Figure 3 Multiple data collections are performed within the specified timeframe to collect multiple test points, and multi-point testing is conducted to avoid testing errors.

[0094] Based on the results of multiple data acquisitions, calculate the standard error of the output voltage of the anemometer bridge under the current calibration conditions:

[0095]

[0096] Where STD represents the standard error (e.g., 0–5V) of the output voltage of the anemometer bridge collected under the current calibration conditions; U i This represents the voltage measurement value of the i-th data acquisition, for example, the voltage of the anemometer bridge is measured n times (e.g., n is 10 times); This represents the mean of the results from n data collections, where n is the number of measurements or data collections.

[0097] Data is considered valid when the standard error reaches the level of 0.05V. Data is considered invalid when the standard error is below the level of 0.05V. Once all calibrations are completed and the results analysis is valid, the next processing stage can begin.

[0098] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.

[0099] Next, in step S105, the calibration matrix of the plurality of sensors to be calibrated is determined based on the determined valid data.

[0100] Specifically, based on the valid data determined in step S104, the calibration matrix of the plurality of sensors to be calibrated is determined.

[0101] It should be noted that in this example, because there is a certain difference between the average nozzle velocity and the velocity in the steady zone, the calibration matrix for each sensor under specific conditions is a matrix composed of two column vectors. For example, the first column is the voltage (measured value of the bridge), and the second column is the target wind speed V. Tar The above are merely optional examples and should not be construed as limiting this application.

[0102] In one specific implementation, a matrix can be formed after each determined calibration parameter becomes valid:

[0103]

[0104] in, The average output voltage value measured at each wind speed (e.g., expressed in V), V ave_n Re represents the average wind speed at each wind speed corresponding to the submerged jet nozzle (i.e., the duct nozzle). n Based on the average wind speed V ave_n Based on the calculated nozzle Reynolds number, the calibration parameter 'a' can be optimized using the above calculation method, thereby forming a matrix:

[0105]

[0106] The left-hand side represents the calibration matrix of the sensor to be calibrated, which represents the voltage measurement value U of the sensor. n And actual wind speed V Tar_n The relationship between them.

[0107] Furthermore, the resulting matrix can be further fitted using the following expression:

[0108] U n 2 =A+BV Tar_n c

[0109] Among them, U n This represents a set of measured voltage values ​​for the sensor to be calibrated; This represents the actual wind speed of the sensor to be calibrated at the corresponding voltage value (i.e., a set of corrected values ​​calculated based on the average wind speed after calibration). A, B, and c represent the first, second, and third coefficients obtained from the fitting, respectively, i.e., based on a set of U... n V Tar_n Obtained through data fitting.

[0110] U, fitted by the above expression n V Tar_n The correlation method can greatly simplify the conversion process of hot-wire anemometer systems.

[0111] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.

[0112] Compared with existing technologies, the low-pressure wind field simulation system of this application can form a more stable submerged jet range by simulating the wind duct, thereby obtaining an extremely uniform wind field. By simultaneously moving multiple sensors to be calibrated in one dimension within the uniform area of ​​the submerged jet range formed by the wind duct outlet to collect relevant data, calibration errors can be effectively reduced. By simultaneously calibrating multiple sensors to be calibrated within the specified area formed by the wind duct nozzle, the calibration workload of the sensors can be reduced more efficiently.

[0113] Furthermore, by controlling and adjusting the temperature and flow rate of the incoming gas, the speed and temperature controllability of the simulated wind field can be improved.

[0114] like Figure 6 As shown, this embodiment provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the method steps described in the above embodiment.

[0115] This application provides a non-volatile computer storage medium storing computer-executable instructions that can perform the steps described in the above embodiments.

[0116] The following is for reference. Figure 6 The diagram illustrates a structural schematic of an electronic device suitable for implementing the embodiments of this application. The terminal devices in the embodiments of this application may include, but are not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 6 The electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0117] like Figure 6 As shown, the electronic device may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage device 408 into a random access memory (RAM) 403. The RAM 403 also stores various programs and data required for the operation of the electronic device. The processing unit 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0118] Typically, the following devices can be connected to I / O interface 405: input devices 406 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 407 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 408 including, for example, magnetic tapes, hard disks, etc.; and communication devices 409. Communication device 409 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 6 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown. More or fewer devices may be implemented or have instead.

[0119] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 409, or installed from a storage device 408, or installed from a ROM 402. When the computer program is executed by the processing device 401, it performs the functions defined in the methods of the embodiments of this application.

[0120] It should be noted that the computer-readable medium described above in this application can be a computer-readable signal medium, a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0121] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device.

[0122] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0123] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0124] The units described in the embodiments of this application can be implemented in software or hardware. The names of the units are not, in some cases, limiting the scope of the unit itself.

Claims

1. A low-pressure wind field simulation system based on submerged jets, characterized in that, include: A space environment simulation container with built-in simulated air ducts; Multiple sensors to be calibrated are deployed near the nozzles of the simulated air duct; A moving mechanism, which is connected to the plurality of sensors to be calibrated, is used to drive the plurality of sensors to be calibrated to move within the range of the submerged jet formed by the simulated wind duct in order to perform wind speed calibration; The air intake duct is connected to the simulated air duct. A gas source, which supplies gas to the simulated air duct through the air intake pipe of the air duct; A flow control component, located between the gas source and the air inlet pipe of the duct, is used to control the inlet gas flow rate of the simulated air duct; A pressure control component connected to the space environment simulation container for controlling the pressure within the space environment simulation container.

2. The low-pressure wind field simulation system based on submerged jet according to claim 1, characterized in that, Further includes: A controller is electrically connected to the moving mechanism, the pressure control component, and the flow control component. The moving mechanism includes a moving block and a stepper motor for driving the moving block to move. The controller controls the moving block to move multiple sensors to be calibrated to the submerged jet range. The controller also controls the exhaust valve and the air inlet valve of the air duct to adjust the bridge resistance and test the multiple sensors under different calibration conditions. The controller is also used to control the stepper motor to rotate so as to drive the moving block to move toward the stepper motor until the moving block contacts the limit switch, that is, to establish the zero coordinate reference for the movement.

3. The low-pressure wind field simulation system based on submerged jet according to claim 1, characterized in that, The simulated air duct sequentially includes an air inlet pipe, an air inlet pipe outlet, a baffle plate, an air duct stabilization section, a rectifier, a first turbulence reduction net, a second turbulence reduction net, a convergence section, and a submerged jet nozzle. The air inlet pipe outlet introduces gas with adjusted temperature and flow rate into the simulated air duct, and the gas is accelerated under the action of the convergence section to form gas flow, further forming the submerged jet of the air duct nozzle. The convergence section includes a bicubic curve configuration.

4. The low-pressure wind field simulation system based on submerged jets according to claim 3, characterized in that, Further includes: Based on the calculated and calibrated inlet gas flow rate, a suitable flow controller is selected, and the pressure inside the space environment simulation container is actively controlled by the flow controller until the environmental parameters of the simulated air duct are stable, so as to form a submerged jet at the nozzle of the simulated air duct.

5. The low-pressure wind field simulation system based on submerged jet according to claim 1, characterized in that, include: After selecting the tapering section of the air duct, the wind speed at the simulated air duct nozzle is corrected: In ave =V Tar / and Among them, V ave V represents the expected average wind speed of the gas exiting the nozzle of the simulated air duct under the current calibration conditions; Tar represents the expected wind speed value near the wind speed sensor; 'a' is a function value related to the duct structure and the outlet Reynolds number, i.e., the calibration parameter.

6. The low-pressure wind field simulation system based on submerged jet according to claim 1, characterized in that, Further includes: The system includes a turbine expander, an inlet pipe, and a heater. The turbine expander enables the gas to expand adiabatically under pressure difference for a first cooling process. The inlet pipe allows heat exchange with the heat sink inside the space environment simulation container for a second cooling process. The heater heats the gas to reach a desired temperature.

7. A method for simulating low-pressure wind fields based on submerged jets, characterized in that, include: Based on different air ducts, determine the Reynolds number under the current calibration conditions, and calculate the inlet gas flow rate required for calibration according to the determined Reynolds number range and the selected air duct. Based on the calculated and calibrated required inlet gas flow rate, select a suitable flow controller and actively control the pressure inside the space environment simulation container until the environmental parameters of the simulated air duct stabilize, so as to form a submerged jet at the nozzle of the simulated air duct. Within the submerged jet range formed by the simulated air duct nozzle, multiple signals are collected from multiple sensors to be calibrated for multi-point testing, and error calculation is performed to determine the valid data. Based on the determined valid data, the calibration matrix of the plurality of sensors to be calibrated is determined.

8. The method for simulating low-pressure wind fields based on submerged jets according to claim 7, characterized in that, include: After selecting the tapering section of the air duct, the wind speed at the simulated air duct nozzle is corrected: In ave =V Tar / and Among them, V ave V represents the expected wind speed after correction based on the duct structure and the outlet Reynolds number; Tar This represents the desired wind speed value near the wind speed sensor; where V ave V represents the expected average wind speed of the gas exiting the nozzle of the simulated air duct under the current calibration conditions; Tar 'a' represents the target wind speed at the duct nozzle; 'a' is a function value related to the duct structure and the outlet Reynolds number, i.e., the calibration parameter.

9. The method for simulating low-pressure wind fields based on submerged jets according to claim 7, characterized in that, When the Reynolds number Re∈[5000,50000), the calibration parameters are calculated using the following expression: a=c5Re 5 +c4Re 4 +c3Re 3 +c2Re 2 +c1Re 1 +c0; Where, 'a' represents the calculated value of the function related to the duct structure and the outlet Reynolds number, i.e., the calibration parameter, and the value of 'a' ranges from 1.0 to 1.4; 'c0' to 'c5' represent the first fitting parameter, the second fitting parameter, the third fitting parameter, the fourth fitting parameter, the fifth fitting parameter, and the sixth fitting parameter obtained by least squares fitting, respectively. When the Reynolds number Re > 50000, a = 1.

10. The method for simulating low-pressure wind fields based on submerged jets according to claim 7, characterized in that, include: The movement of the moving block is driven by the rotation of the stepper motor until the moving block contacts the limit switch, thus establishing the zero coordinate reference for the movement. The moving block is controlled to move, thereby moving multiple sensors to be calibrated within the range of the submerged jet. By controlling the exhaust valve and the air inlet valve of the air duct, the resistance of the bridge is adjusted to test the multiple sensors under different calibration conditions.

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