Bidirectional self-balancing anti-crosswind device for Laval nozzle of cable-stayed bridge

Abstract

The invention discloses a bidirectional self-balancing crosswind-resistant device for a Laval nozzle of a cable-stayed bridge, and belongs to the technical field of bridge wind-resistant and vibration-proof devices. The device comprises a stand column, Laval-shaped ventilation pipes, an air storage chamber, an air pressure pump, a controller, a sensor and an exhaust pipe, and the multiple ventilation pipes are fixed to the two sides of the bridge column and are linearly arranged at intervals. The invention provides a new thought for wind resistance and vibration prevention of the bridge, and has the advantages of simple structure, low cost and remarkable windproof effect.

Description

Technical Field

[0001] The invention belongs to the technical field of wind-resistant and vibration-proof devices, in particular to a Laval nozzle bidirectional self-balancing crosswind-resistant device for a cable-stayed bridge. Background Art

[0002] With the development and progress of my country's infrastructure, bridge construction, as an important component, plays an irreplaceable role. Cable-stayed bridges are widely used bridge systems in modern transportation engineering. Due to the characteristics of low damping, high flexibility and light weight of cable-stayed bridges, bridges are prone to vibration under the stimulation of external excitation sources such as typhoons and rainstorms. Typhoons and other strong winds, as a natural disaster with a high frequency, pose a serious threat to bridges. The large-scale lateral vibration of cable-stayed bridges affected by external excitations can easily cause repeated stress changes in the cable-stayed bridge deck. In this case, it is particularly important to ensure the quality and safety of the bridge, and the wind-resistant vibration reduction of the bridge. The design and use of bridge wind-resistant vibration-proof devices can effectively improve the stability of the bridge in the face of extreme natural disasters and extend the service life of the bridge. The current windproof structure is relatively simple, and the common method is to set windproof nets on both sides of the bridge, but it can only offset part of the wind force and has a high cost. The application of the present invention to cable-stayed bridges will be able to solve the wind-resistant vibration problem of cable-stayed bridges at a low cost, simply and effectively. Summary of the invention

[0003] The object of the present invention is to provide a bidirectional self-balancing crosswind resistance device for a Laval nozzle of a cable-stayed bridge, so as to achieve the purpose of wind and vibration resistance of the cable-stayed bridge with high efficiency and low cost.

[0004] The technical solution to achieve the purpose of the present invention is: A Laval nozzle bidirectional self-balancing anti-crosswind device for a cable-stayed bridge, characterized in that it includes: the Laval duct, including a stage of reduced cross-sectional area, a throat, and a stage of increased cross-sectional area, and a top through hole, which plays a role in suppressing the vibration of the bridge caused by cross-sectional wind; the column is installed below the Laval duct to play a supporting role; the air storage chamber is installed above the Laval duct to store gas; the air pressure pump is installed above the Laval duct, including an air inlet pipe and an air outlet pipe, and the bottom end of the air outlet pipe is a thickened outer ring connected to the air storage chamber to pressurize the gas; the controller is installed above the Laval duct to control the air pressure pump; the sensor is installed above the Laval duct to transmit the detected external wind force information to the controller. The exhaust pipe is connected below the air pressure pump, and includes an air inlet, an internal groove, an expansion exhaust port, and a tail fin. It can rotate 360 ​​degrees and has a downwind guiding structure. The Laval duct is installed and fixed on both sides of the bridge. Five Laval ducts are installed and fixed on one side. The Laval ducts are aligned in a straight line. The structures on both sides of the bridge are symmetrical. Two upper and lower Laval ducts are installed on the side of the cable-stayed bridge, which are combined with the air outlet at one end in the same direction of the side of the cable-stayed bridge to completely block the side of the bridge. When the wind passes from the side, it will directly enter the Laval duct to play a role of wind blocking. The air pressure pump is connected to the air storage box through an air inlet pipe, and the air outlet pipe of the air pressure pump enters its throat through the hole in the middle of the Laval duct. A groove is provided in the air duct orifice, which is inlaid with the thickened outer ring of the air pressure pump to play the role of a rotating pair. A hollow tail fin is provided on the side, so that the air supply duct body can test the wind direction and the exhaust port can be adjusted according to the wind direction to make the exhaust duct downwind.

[0005] The working principle of the present invention is: When the transverse wind passes through the Laval duct, the gas passes through the stage of decreasing cross-sectional area. The gas movement follows the principle that "when the fluid moves in the tube, the flow velocity is large at the small cross-sectional area and small at the large cross-sectional area", so the airflow is constantly accelerated. When it reaches the throat, the flow velocity has reached the speed of sound. The larger the cross-sectional area of ​​the supersonic fluid in the expansion section, the faster the flow velocity. In the stage where the gas passes through the wind duct with increasing cross-sectional area, the speed of the airflow is further accelerated. The pipe wall on the side with high flow velocity is subjected to reverse force, thereby suppressing the vibration of the bridge caused by the transverse wind. In addition, an air storage chamber is installed on the Laval nozzle, and a pressure pump is used to increase the pressure, so that the airflow in the throat can adjust the flow and momentum by injecting high-pressure gas mass, and then realize the supersonic reverse thrust airflow with adjustable gas flow and momentum in the expansion section. The stress feedback from the sensor is used to control the size of the high-pressure gas flow added in the throat, and the gas flow size in the expansion section is adjusted to adjust the size of the reverse thrust of the supersonic airflow.

[0006] Compared with the prior art, the present invention has the following significant advantages: (1) The reaction force generated by the wind speed difference on both sides of the air duct is mainly used as the main force to suppress the vibration of the bridge, and the vibration of the bridge can be controlled in a timely and effective manner.

[0007] (2) Wind itself is used as the force medium, which does not pollute the environment.

[0008] (3) The wind-proof and vibration-proof device has a simple overall structure, is easy to install, and has high reliability.

[0009] (4) The wind-proof and vibration-proof device is low-cost and can be installed and removed at any time and replaced uniformly.

[0010] (5) When the side of the bridge is affected by strong winds, the wind mainly enters from the nozzle, thereby reducing the force of the wind on the side of the bridge. At the same time, the wind reaches supersonic speed when it is ejected from the other side of the nozzle, which will produce a reaction force on the bridge, further suppressing the effect of the wind on the side of the bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the Laval nozzle bidirectional self-balancing crosswind resistance device for a cable-stayed bridge of the present invention; Figure 2 It is a side view of a cable-stayed bridge of the Laval nozzle bidirectional self-balancing crosswind resistance device of the cable-stayed bridge of the present invention; Figure 3 It is a partial enlarged view of the Laval nozzle bidirectional self-balancing crosswind resistance device of the cable-stayed bridge of the present invention; Figure 4 is a detailed diagram of the Laval air duct of the present invention; Figure 5 It is a schematic diagram of the air storage chamber of the Laval nozzle bidirectional self-balancing crosswind resistance device of the cable-stayed bridge; Figure 6 It is a detailed diagram of the air pressure pump of the Laval nozzle bidirectional self-balancing crosswind resistance device of the cable-stayed bridge; Figure 7 It is a schematic diagram of the controller of the Laval nozzle bidirectional self-balancing crosswind resistance device of the cable-stayed bridge; Figure 8 It is a schematic diagram of the sensor of the Laval nozzle bidirectional self-balancing anti-crosswind device of the cable-stayed bridge; Fig. 9 It is a schematic diagram of the exhaust pipe of the Laval nozzle bidirectional self-balancing anti-crosswind device of the cable-stayed bridge; Fig.10 It is a detailed cross-sectional view of the exhaust pipe of the Laval nozzle bidirectional self-balancing anti-crosswind device of the cable-stayed bridge; Fig.11 This is a detailed cross-sectional view of the connection between the exhaust pipe and the air pressure pump of the Laval nozzle bidirectional self-balancing anti-crosswind device of the cable-stayed bridge. DETAILED DESCRIPTION

[0012] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0013] Combination Figure 1-Figure 8 The Laval nozzle bidirectional self-balancing and anti-crosswind device for a cable-stayed bridge of this embodiment is characterized by comprising a Laval air duct 1, a column 2, an air storage chamber 3, an air pressure pump 4, a controller 5, a sensor 6, and an exhaust pipe 7. The Laval air duct 1 is installed and fixed on both sides of the bridge, and includes a stage 101 where the cross-sectional area is reduced, a throat 102, a stage 103 where the cross-sectional area is increased, and a top through hole 104. The column 2 is installed and fixed under the Laval air duct 1 as a support. The air storage chamber 3 is installed above the Laval air duct 1 to store gas, including an exhaust port 301. The air pressure pump 4 is installed above the Laval air duct 1 to control the air pressure, including an air inlet pipe 401, an air outlet pipe 402, a thickened ring 403 at the end of the air outlet pipe, and a signal line 404, which is connected to the air storage chamber 3 through the air inlet pipe 401 to pressurize the gas flowing through the air storage chamber 3. The controller 5 is installed on the Laval The sensor 6 is installed above the Laval air duct 1 to detect the external wind force at this time, and includes a pair of interfaces 601, which are connected to the controller 5 through the interfaces 601 to transmit the information to the controller 5. The exhaust pipe 7 is connected below the air outlet pipe 402 of the air pump 4, and is located inside the Laval air duct 1 to play a role of downwind reversing, including an air inlet 701, an air outlet 702, a tail wing 703, and an internal groove 704.

[0014] When the transverse wind passes through the Laval duct 1, the airflow is continuously accelerated when the gas passes through the stage 101 where the cross-sectional area is reduced. When it reaches the throat 102, the flow velocity has reached the speed of sound. When the gas passes through the stage 103 where the cross-sectional area of ​​the duct is increased, the speed of the airflow is further accelerated, and the pipe wall on the side with a high flow velocity is subjected to a reverse force, thereby suppressing the vibration of the bridge caused by the transverse wind. The sensor 6 starts to detect the wind force and transmits the information to the controller 5. The controller 5 controls the air pressure pump 4 to adjust the air flowing into the air storage chamber 3. The body is pressurized and the gas is discharged into the exhaust pipe 7 through the outlet pipe 402. The internal groove 702 of the exhaust pipe 7 is embedded with the thickened ring 403 of the air pressure pump 4 to form a rotating pair, which can rotate 360 ​​degrees according to the external wind direction. A hollow tail wing piece 704 is arranged on the side, so that the air supply pipe body can turn the exhaust port 703 to the downwind direction according to the change of wind direction, so that the exhaust is smoother, and the direction of the reverse thrust is automatically adapted to and changed, thereby increasing the internal air pressure of the Laval air duct 1, further increasing the reverse force, and reducing the vibration of the bridge.

Claims

1. The Laval nozzle bidirectional self-balancing anti-crosswind device of the cable-stayed bridge is characterized by include: Laval wind tunnel (1), which serves to suppress the vibration of the bridge caused by lateral wind; A column (2) is installed below the Laval air duct (1) to play a supporting role; An air storage chamber (3) is installed above the Laval air duct (1) and serves to store gas; An air pressure pump (4) is installed above the Laval air duct (1) and connected to the air storage chamber (3) to increase the pressure of the gas; A controller (5) is installed above the Laval air duct (1) and plays a role in controlling the air pressure pump (4); A sensor (6) is installed above the Laval wind duct (1) and transmits the detected external wind force information to the controller (5); An exhaust pipe (7) is connected to the lower side of the air pressure pump (4), can rotate 360 ​​degrees, and has a downwind guiding structure; When the transverse wind passes through the Laval duct (1), the airflow is continuously accelerated when the gas passes through the stage (101) where the cross-sectional area decreases. When the gas reaches the throat (102), the flow velocity has reached the speed of sound. When the gas passes through the stage (103) where the cross-sectional area of ​​the duct increases, the speed of the airflow is further accelerated, and the tube wall on the side with a high flow velocity is subjected to a reverse force, thereby suppressing the vibration of the bridge caused by the transverse wind. The Laval air duct (1) comprises a stage (101) with a reduced cross-sectional area, a throat (102), a stage (103) with an increased cross-sectional area, and a top through hole (104); An exhaust port (301) is provided on the side of the air storage chamber (3); The air pressure pump (4) comprises an air inlet pipe (401), an air outlet pipe (402), the bottom end of the air outlet pipe (402) is a thickened outer ring (403), and a signal line (404); The controller (5) includes a pair of sensor connection lines (501) and a signal line interface (502); The sensor (6) comprises a pair of interfaces (601); The air duct (7) includes an air inlet (701), an internal groove (702), an expanded exhaust port (703), and a tail wing (704), and is connected to the air outlet pipe (302) of the air pressure pump (4) through the pipe mouth (701). The thickened outer ring (403) of the air pressure pump (4) is embedded in the internal groove (702) to play the role of a rotating pair. The expanded exhaust port (703) increases the air flow speed and can be better affected by the external wind force. The tail wing (704) is in the shape of a hollow pointed cone, and the more pointed end of the cone is located on the side of the exhaust port, so that the exhaust duct can better conform to the external wind direction.

2. The Laval nozzle bidirectional self-balancing crosswind resistance device for a cable-stayed bridge according to claim 1 is characterized in that: The Laval air duct (1) is installed and fixed on both sides of the bridge. Five Laval air ducts (1) are installed and fixed on one side. The Laval air ducts (1) are aligned in a straight line. The structures on both sides of the bridge are symmetrical. Two upper and lower Laval air ducts (1) are installed on the side of the cable-stayed bridge. They are combined with the air outlet at one end of the side of the cable-stayed bridge in the same direction to completely block the side of the bridge. When wind passes through the side, it will directly enter the Laval air duct (1) to play a role in blocking the wind.

3. The Laval nozzle bidirectional self-balancing crosswind resistance device for a cable-stayed bridge according to claim 1 is characterized in that: The air pressure pump (4) is connected to the exhaust port (301) of the air storage chamber (3) via an air intake pipe (301), and the signal line (404) is connected to the signal line interface (502).

4. The Laval nozzle bidirectional self-balancing anti-crosswind device for a cable-stayed bridge according to claim 1 or 3, characterized in that: The air outlet pipe (402) of the air pressure pump (4) enters the interior of the Laval air duct (1) through the hole (104) in the middle of the Laval air duct (1).

5. The Laval nozzle bidirectional self-balancing crosswind resistance device for a cable-stayed bridge according to claim 1 is characterized in that: The controller (5) sensor connection line (501) is connected to the sensor (6) interface (601).

6. The Laval nozzle bidirectional self-balancing anti-crosswind device for a cable-stayed bridge according to claim 1 or 3, characterized in that: The air duct (7) is provided with a groove (702) in the pipe opening, which is embedded with the thickened outer ring (403) of the air pressure pump (4) to fix the two components. A hollow tail wing (704) is provided on the side, so that the air duct body can test the wind direction and the exhaust port can be adjusted according to the wind direction so that the exhaust duct is facing the wind.

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