Wind tunnel model resistance measuring device based on gravity

Abstract

The invention belongs to the technical field of resistance measurement, and relates to a wind tunnel model resistance measurement device based on gravity, which comprises a balance assembly and an angle adjustment assembly arranged in a wind tunnel model, the balancing assembly comprises a platform arranged on the angle adjusting assembly, a guide rail arranged on the platform and sensors arranged at the two ends of the guide rail. The angle adjusting assembly is used for adjusting the horizontal inclination angle of the platform, so that an object to be measured arranged on the guide rail can slide along the guide rail under the action of gravity; and adjusting the angle adjusting assembly bidirectionally until the two sensors do not output signals, and obtaining the resistance of the to-be-measured object in the wind tunnel model according to the horizontal inclination angle of the platform. According to the invention, the wind resistance of the model can be accurately measured.

Description

Technical Field

[0001] The present application relates to the technical field of resistance measurement, and in particular to a wind tunnel model resistance measurement device based on gravity. Background Art

[0002] As an important device for studying the aerodynamic performance of moving objects, the wind tunnel model drag measurement device can not only verify the reliability of numerical simulation results, but also help engineers test the effects of different part design schemes.

[0003] In the prior art, in order to measure the resistance of a car or other object, the traditional resistance measurement device directly measures the total resistance of the model by using a force sensor (such as a force balance). In addition, there is also a method of fixing the car and then installing a differential pressure sensor on the outside of the car body to measure the static pressure difference on the surface of the car to calculate the resistance of the car.

[0004] The above-mentioned resistance measurement device can basically measure the resistance of the car relatively accurately through the cooperation of the sensor in the wind tunnel. However, there are still the following problems: 1. Accurate measurement of traditional pressure requires high precision of instruments. The complete set of pressure measurement devices is a high-cost equipment, which brings great economic pressure to some non-industrial institutional research projects; 2. The traditional solution more or less requires the installation of force sensors on the object, which is a contact measurement solution, affecting the flow field structure, making the final measured resistance have an unknown difference from the actual resistance; 3. Traditional devices are not universal for measuring the resistance of different objects in wind tunnels. When measuring different objects, it is necessary to reinstall sensors and adjust parameters. The experimental steps are relatively cumbersome when measuring multiple times. Summary of the invention

[0005] Based on this, it is necessary to provide a gravity-based wind tunnel model resistance measurement device to address the above technical problems, which can achieve accurate measurement of the model wind resistance.

[0006] A wind tunnel model resistance measurement device based on gravity, comprising: a balance component and an angle adjustment component arranged in the wind tunnel model; The balancing assembly comprises: a platform arranged on the angle adjustment assembly, a guide rail arranged on the platform, and sensors arranged at both ends of the guide rail; The angle adjustment assembly is used to adjust the horizontal inclination angle of the platform so that the object to be measured disposed on the guide rail can slide along the guide rail under the action of gravity; The angle adjustment assembly is bidirectionally adjusted until both sensors do not output signals, and the resistance of the object to be measured in the wind tunnel model is obtained according to the horizontal inclination angle of the platform.

[0007] In one embodiment, the guide rail is a magnetic levitation guide rail.

[0008] In one embodiment, the length direction of the guide rail is consistent with the length direction of the wind tunnel model.

[0009] In one embodiment, the balancing assembly and the angle adjustment assembly are both arranged in a test section of a wind tunnel model.

[0010] In one embodiment, the balancing assembly and the angle adjustment assembly are both connected to the wind tunnel model via an airtight and stretchable rubber layer to form a transition structure.

[0011] In one embodiment, obtaining the resistance of the object to be tested in the wind tunnel model according to the horizontal inclination angle of the platform includes:

[0012] In the formula, is the resistance of the object to be tested in the wind tunnel model, is the mass of the object to be measured, is the acceleration due to gravity, is the horizontal inclination angle of the platform.

[0013] In one embodiment, the angle adjustment assembly includes: a top plate, a bottom plate, and a telescopic mechanism; The two corresponding ends of the top plate and the bottom plate are connected by a telescopic mechanism, so that the top plate is hinged to one corresponding end of the bottom plate, and the other corresponding end of the top plate and the bottom plate are spaced apart so that the platform has a non-zero horizontal inclination angle.

[0014] In one embodiment, the telescopic mechanism comprises: a telescopic member, a top seat, a base and a motor; The two ends of the telescopic member are respectively hinged to the top seat and the base. The telescopic member is also connected to the motor and has different states of extension and contraction under the driving action of the motor to adjust the horizontal inclination angle of the platform.

[0015] In one embodiment, the telescopic member comprises: a worm wheel and a worm; The output end of the motor is rotationally connected to the worm wheel, and the edge of the worm wheel is meshed with the worm.

[0016] In one embodiment, the telescopic member comprises: a sleeve and a screw rod; The output end of the motor is rotatably connected to the sleeve, the sleeve is sleeved on the outside of the screw rod, and the sleeve is threadedly connected to the screw rod.

[0017] The above-mentioned gravity-based wind tunnel model resistance measurement device is designed with a balance component and an angle adjustment component to achieve precise balance of the object under test in the airflow, and converts the actual airflow resistance exerted on the object into the component of the object's gravity along the platform through force balance. The gravity component is obtained by analyzing the force exerted on the object, and then the resistance exerted on the object under wind tunnel conditions is obtained. This enables rapid measurement of the model's wind resistance and ensures high accuracy of the resistance measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a balance assembly of a wind tunnel model drag measurement device based on gravity in one embodiment; Figure 2 A schematic diagram of an angle adjustment assembly of a gravity-based wind tunnel model drag measurement device according to an embodiment; Figure 3 is a three-dimensional schematic diagram of a balance component of a wind tunnel model resistance measurement device based on gravity in another embodiment; Figure 4 It is a front view of a balance assembly of a wind tunnel model resistance measurement device based on gravity in another embodiment, wherein the circle is a schematic diagram of the connection between the pulley and the guide rail body; Figure 5 for Figure 3 Detailed schematic diagram of the structure in the middle circle; Figure 6 Schematic diagram of a wind tunnel model in one embodiment.

[0019] Reference numerals: Air inlet A, expansion section B, test section C, air outlet D; Platform 1, guide rail 2, body 21, magnetic member 22, support part 23, sensor 3, connector 4, support platform 41, pulley 42, inner core 421, bearing 422, outer ring 423, ball 424; Top plate 5, bottom plate 6, telescopic mechanism 7. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0021] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "multiple groups" means at least two groups, such as two groups, three groups, etc., unless otherwise clearly and specifically defined.

[0023] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0025] The present application provides a wind tunnel model resistance measurement device based on gravity, such as Figure 1 and Figure 2 As shown, in one embodiment, it includes: a balancing component and an angle adjustment component.

[0026] The balancing component is used to make the object to be measured on the balancing component reach force balance. The balancing component includes: a platform, a guide rail and a sensor; the platform is rigidly connected to the angle adjustment component (the specific connection method is the existing technology) to provide support for the guide rail and the sensor; the guide rail (the specific structure can adopt the existing technology) is set on the platform to support the object to be measured; there are two sensors, which are respectively set at both ends of the guide rail to detect the position of the object to be measured and determine whether the object to be measured has reached force balance. For example, the sensor is a pyroelectric position sensor, which uses a thermal crystal with polarization phenomenon (such as ferroelectrics). When irradiated with infrared radiation, it causes temperature changes, reduces polarization intensity, and reduces surface charge. It has high sensitivity and fast response characteristics; in actual use, infrared rays are always irradiated to the sensor, and the sensor has no output signal. When the platform deviates to one side, it will block the infrared rays, so that the sensor has an output signal, so that it deviates to the other side. When there is no output signal on both sides, it is judged that the object to be measured has reached force balance.

[0027] The angle adjustment component is used to adjust the horizontal inclination of the platform so that the object to be tested on the guide rail can slide along the guide rail under the action of gravity, ensuring that the object resistance and the gravity force component along the guide rail direction can be balanced under general working conditions.

[0028] In this embodiment, the balancing component and the angle adjustment component are both arranged in the wind tunnel model; the angle adjustment component is adjusted bidirectionally until both sensors have no output signals, and it is determined that the object to be tested reaches force balance (that is, the wind resistance and the gravity force along the guide rail surface are balanced). Through force analysis, according to the horizontal inclination angle of the platform, the resistance of the object to be tested under specific working conditions in the wind tunnel model is obtained:

[0029] In the formula, is the resistance of the object to be tested in the wind tunnel model, is the mass of the object to be measured, is the acceleration due to gravity, is the horizontal inclination angle of the platform.

[0030] Preferably, the guide rail is a magnetic levitation guide rail, so as to reduce friction through magnetic suspension and maintain an ultra-low resistance state, thereby reducing measurement errors and improving measurement accuracy.

[0031] Further preferably, the length direction of the guide rail is consistent with the length direction of the wind tunnel model to ensure the consistency of the airflow direction with the axial direction of the stable section, avoid the influence of the airflow direction deviation on the experimental results, and will not affect the direction angle between the airflow and the object.

[0032] More preferably, if Figures 3 to 5As shown, the balance component also includes: a connecting member, so that the object to be measured can be placed on the guide rail through the connecting member. Specifically: the guide rail includes a body and a magnetic member; there are two bodies, which are spaced and arranged in parallel on both sides of the platform, and the body includes a first part, a second part and a third part that are connected in sequence, and the cross-sectional width of the second part is smaller than that of the first part and the third part at the same time, so that the cross-sectional width of the body forms an "I"-shaped structure, and a curved groove is provided on the corner end of the first part away from the second part so that the top surface of the body of the guide rail has a concave arc-shaped top angle, and the side surface of the second part is recessed in the direction of the axis of the guide rail so that the body of the guide rail forms a concave arc-shaped side surface, with the arc-shaped top angle of the first part as the top surface and the arc-shaped side surface of the second part as the bottom surface, so that the side surface of the guide rail body forms a convex support portion; the magnetic member is arranged between the two bodies, and is divided into an upper magnet and a lower magnet, the upper magnet is connected to the connecting member, and the lower magnet is connected to the platform, and the polarity of the upper magnet and the lower magnet is the same, so as to produce The repulsive magnetic force forms a uniform gap between the upper magnet and the lower magnet, realizing the suspension and guiding functions; the connecting part includes a support platform and a pulley; the support platform is a flat structure made of high-strength materials such as aluminum alloy, the middle part is fixedly connected to the upper magnet, and the two sides are connected to the side surfaces of the guide rail through pulleys; the pulley is a rotating body structure, including an inner core, a bearing and an outer ring which are sequentially arranged from the inside to the outside, the inner core is a cylindrical structure and is fixedly connected to the support platform, the bearing abuts against the inner core and the outer ring, and a slide groove is provided on the side surface of the outer ring to connect with the top and bottom surfaces of the support part so that the slide groove cooperates with the support part, and a spherical ball is nested at the position of the slide groove connected to the top and bottom surfaces of the support part, so that the outer ring of the pulley is driven to rotate between the side surface of the outer ring of the pulley and the side surface of the guide rail through the rolling of the ball, so that the pulley slides on the guide rail body, that is, a sliding connection is formed through a rolling connection.

[0033] The above arrangement can improve the stability of the balancing assembly in the wind tunnel, reduce the impact of vibration, and increase the friction area to further reduce friction, thereby improving the accuracy of the measurement; at the same time, the connecting piece is arranged in the middle position of the guide rail body to avoid inaccurate experimental results due to too small angle adjustment.

[0034] More preferably, the balancing component and the angle adjustment component are both arranged in the test section of the wind tunnel model, and the wind tunnel model adopts a flow intelligent control system to provide a stable airflow environment for the wind tunnel model and support the entire measuring device. Specifically, the flow intelligent control system includes: a flow sensor, a control module and an actuator connected in sequence; the flow sensor is used to monitor the airflow flow inside the wind tunnel model in real time and output a signal to the control module, the control module (including an anemometer, installed after the fan of the wind tunnel, through intelligent control of the flow, thereby controlling the wind speed) calculates the airflow flow that needs to be adjusted through a preset intelligent control algorithm (belonging to the existing technology, such as PID control, Fuzzy control or AI algorithm) and sends it to the actuator, and the actuator adjusts the airflow valve and other components in the wind tunnel model accordingly, thereby achieving precise control of the airflow flow; the flow intelligent control system also includes: an airflow stabilization module arranged on the anemometer, which adopts a closed-loop feedback control technology (existing technology) to ensure the stability of the airflow environment and avoid airflow fluctuations caused by external interference. Compared with the existing technology, the above-mentioned intelligent flow control system has the innovative features of intelligent control and multi-dimensional monitoring. It can dynamically adjust the airflow according to real-time data, and combine other parameters (such as temperature, pressure, etc.) for comprehensive control, thereby significantly improving the stability of the airflow environment; the system achieves fine-tuning control of the airflow through precise sensors and high-performance actuators to ensure the high stability of the airflow environment; the application of this system can significantly improve the stability of the airflow environment of the wind tunnel model, reduce the impact of external interference on the airflow environment, and quickly respond to changes in airflow through intelligent control to maintain the stability of the airflow environment, thereby significantly improving the measurement accuracy of the wind tunnel model and ensuring the reliability of the entire measurement device. It should be noted that the specific structures of the flow sensor, control module, actuator and airflow stabilization module all belong to the existing technology.

[0035] More preferably, the angle adjustment component is connected to the wind tunnel model by an airtight and stretchable rubber layer (for example, silicone rubber, having good plasticity and sealing properties) to form a transition structure for the sealed connection of the wind tunnel device. The airtight and stretchable rubber layer can effectively prevent airflow intersection or leakage between the wind tunnel model and the external environment due to its good sealing performance and stretchability, thereby ensuring the sealing of the wind tunnel device. At the same time, the airtight and stretchable rubber layer can change according to the shape and structure of the wind tunnel model to achieve a more flexible sealed connection, thereby reducing the problem of sealing failure caused by dimensional errors or structural deformation. In addition, the airtight property of the airtight and stretchable rubber layer can effectively prevent interference from external air, facilitate angle adjustment, and further improve the airflow stability of the wind tunnel device.

[0036] The working process of this application is: 1. The wind tunnel model includes: air inlet, expansion section, test section and outlet D (such as Figure 6As shown, the object to be tested is placed on the balancing component of the test section, specifically on the supporting table of the balancing component; 2. Move the support table horizontally so that it touches the sensor at one end; 3. Adjust the working state of the fan in the wind tunnel model until the fan supplies air stably; 4. Turn on the detection sensor and slowly adjust the angle of the balancing device so that the object to be measured tilts the support platform due to gravity until the sensor at the other end is also blocked and sends a signal; 5. Adjust the angle of the balancing device in the opposite direction to half of the previous angle of the balancing device, until the sensors in both directions are not blocked and no signal is sent out. At this time, the force on the object is balanced; 6. Record the angle between the stable segment and the ground, that is, the angle between the plane where the object is located and the horizontal plane , get the resistance of the object.

[0037] The above-mentioned gravity-based wind tunnel model resistance measurement device is designed with a balance component and an angle adjustment component to achieve precise balance of the object under test in the airflow, and converts the actual airflow resistance exerted on the object into the component of the object's gravity along the platform through force balance, so as to obtain the gravity component through force analysis of the object, and then obtain the resistance exerted on the object under wind tunnel conditions. It can realize rapid measurement of the model wind resistance, ensure high accuracy of resistance measurement, and achieve the effect of precise measurement of airflow resistance.

[0038] In addition, this application also has the following technical effects: 1. It only needs to ensure that the object does not slide on the guide rail, and the measurement accuracy of the instrument is not required to be high, which reduces the equipment cost and the economic pressure of the project; 2. It is not necessary to install a force sensor on the object. It is a non-contact measurement of the actual resistance of the object, avoiding the additional interference of contact measurement, and has less impact on the airflow structure of the original flow field. It can restore the flow field around the object during movement to a large extent, making the final measured resistance more in line with the actual situation and more accurate. 3. It is universal for measuring the resistance of different objects in wind tunnels. It can measure the resistance of objects of various shapes in wind tunnels. When measuring different objects, there is no need to reinstall sensors or readjust parameters. The steps are simple, the operation is quick, the experimental operation is less difficult, and it is convenient for multiple measurements.

[0039] In one embodiment, the angle adjustment assembly includes: a top plate, a bottom plate, and a telescopic mechanism.

[0040] The two corresponding ends of the top plate and the bottom plate are connected by a telescopic mechanism, so that one corresponding end of the top plate and the bottom plate is hinged, and the other corresponding end of the top plate and the bottom plate is spaced apart so that the platform has a non-zero horizontal inclination angle.

[0041] Preferably, the telescopic mechanism includes: a telescopic member, a top seat, a base and a motor. The two ends of the telescopic member are respectively hinged to the top seat and the base, and the telescopic member is also connected to the motor. Under the driving action of the motor, the telescopic member has different states of extension and contraction, so as to accurately adjust the horizontal inclination angle of the platform according to actual needs, and has high flexibility and adjustability, thereby providing a stable test environment for the wind tunnel device.

[0042] For example, the telescopic part includes: a worm wheel and a worm; the output end of the motor is rotationally connected to the worm wheel, and the edge of the worm wheel is meshed with the worm, which can achieve smooth rotation and precise angle adjustment.

[0043] For another example, the telescopic member includes: a sleeve and a screw rod; the output end of the motor is rotatably connected to the sleeve, the sleeve is sleeved on the outside of the screw rod, and the sleeve is threadedly connected to the screw rod, which can ensure the stability and durability of the telescopic mechanism.

[0044] The telescopic mechanism of the above-mentioned angle adjustment component has high flexibility and adjustability, and can accurately adjust the horizontal inclination angle of the platform according to actual needs, thereby providing a stable testing environment for the wind tunnel model; through the drive and precise engagement of the telescopic mechanism, precise control of the horizontal inclination angle of the platform is achieved, which not only improves the adjustment accuracy of the wind tunnel model, but also provides it with a more stable testing environment, reducing measurement errors caused by inaccurate inclination angles; the motor-driven telescopic parts can achieve fast and smooth angle adjustment, further improving the stability of the test environment of the wind tunnel model; it can be dynamically adjusted according to the specific needs of the wind tunnel model, reducing the problem of inclination misalignment caused by dimensional errors or structural deformation; the telescopic mechanism is scalable and maintainable, and the modular design enables each component to be replaced and repaired independently, extending the service life of the device.

[0045] In addition, by adjusting the angle of the stabilizing section as a whole (the specific adjustment method belongs to the existing technology), the airflow direction can be ensured to be consistent with the axial direction of the stabilizing section, avoiding changes in resistance caused by inconsistency.

[0046] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0047] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A wind tunnel model resistance measurement device based on gravity, characterized in that: include: A balancing component and an angle adjustment component provided in a wind tunnel model; The balancing assembly comprises: a platform arranged on the angle adjustment assembly, a guide rail arranged on the platform, and sensors arranged at both ends of the guide rail; The angle adjustment assembly is used to adjust the horizontal inclination angle of the platform so that the object to be measured disposed on the guide rail can slide along the guide rail under the action of gravity; The angle adjustment assembly is adjusted bidirectionally until both sensors do not output signals, and the resistance of the object to be measured in the wind tunnel model is obtained according to the horizontal inclination angle of the platform.

2. The wind tunnel model resistance measurement device based on gravity according to claim 1, characterized in that: The guide rail is a magnetic levitation guide rail.

3. The wind tunnel model resistance measurement device based on gravity according to claim 2, characterized in that: The length direction of the guide rail is consistent with the length direction of the wind tunnel model.

4. The wind tunnel model resistance measurement device based on gravity according to claim 3, characterized in that: The balancing component and the angle adjustment component are both arranged in a test section of the wind tunnel model.

5. A wind tunnel model resistance measurement device based on gravity according to any one of claims 1 to 4, characterized in that: The balancing component and the angle adjustment component are both connected to the wind tunnel model through an airtight and stretchable rubber layer to form a transition structure.

6. A wind tunnel model resistance measurement device based on gravity according to any one of claims 1 to 4, characterized in that: According to the horizontal inclination angle of the platform, the resistance of the object to be tested in the wind tunnel model is obtained, including: In the formula, is the resistance of the object to be tested in the wind tunnel model, is the mass of the object to be measured, is the acceleration due to gravity, is the horizontal inclination angle of the platform.

7. A wind tunnel model resistance measurement device based on gravity according to any one of claims 1 to 4, characterized in that: The angle adjustment assembly includes: a top plate, a bottom plate and a telescopic mechanism; The two corresponding ends of the top plate and the bottom plate are connected by a telescopic mechanism, so that the top plate is hinged to one corresponding end of the bottom plate, and the other corresponding end of the top plate and the bottom plate are spaced apart so that the platform has a non-zero horizontal inclination angle.

8. The wind tunnel model resistance measurement device based on gravity according to claim 7, characterized in that: The telescopic mechanism comprises: a telescopic member, a top seat, a base and a motor; The two ends of the telescopic member are respectively hinged to the top seat and the base. The telescopic member is also connected to the motor and has different states of extension and contraction under the driving action of the motor to adjust the horizontal inclination angle of the platform.

9. The wind tunnel model resistance measurement device based on gravity according to claim 8, characterized in that: The telescopic member comprises: a worm wheel and a worm; The output end of the motor is rotationally connected to the worm wheel, and the edge of the worm wheel is meshed with the worm.

10. The wind tunnel model resistance measurement device based on gravity according to claim 8, characterized in that: The telescopic member comprises: a sleeve and a screw rod; The output end of the motor is rotatably connected to the sleeve, the sleeve is sleeved on the outside of the screw rod, and the sleeve is threadedly connected to the screw rod.

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