A vortex control method and device for improving train operation safety in a strong wind environment

Abstract

The application provides a vortex control method for improving train operation safety in a strong wind environment, when the train encounters crosswind, a small-scale flow vortex is generated under the crosswind through a vortex generator on the leeward side of the top surface of the train, the flow vortex develops to the leeward side of the downstream, is sucked into a large-scale trailing vortex on the leeward side of the train, the strength of the trailing vortex is reduced, the pressure on the leeward side of the train is improved, and the lateral force and overturning moment of the train are reduced. The application starts from the idea of active intervention on the vortex structure interference of the flow field in the near-body area of the running train, realizes the active control on the train safety under the strong wind environment through the vortex generator on the top surface of the train, breaks through the traditional passive control measure research thought of the train safety under the wind environment, provides a new research thought for the active control of the train operation safety, and provides a valuable reference for the research on the active control technology of the train operation safety by using the similar vortex generator control method.

Description

Technical Field

[0001] This invention relates to the field of train safety technology, and in particular to a vortex control method and device for improving train operation safety in windy conditions. Background Technology

[0002] With the rapid development and application of new drag reduction technologies for high-speed trains, operating speeds have increased to 400 km / h, greatly improving commuting efficiency. However, this increased speed has led to a deterioration in train stability and safety. When a train experiences a tilting moment due to strong winds, it may pose a greater risk of instability, affecting daily operational safety and, in severe cases, even causing major railway accidents such as train derailment.

[0003] Currently, there are three main methods to address the deterioration of train aerodynamic performance under crosswinds: first, establishing a strong wind monitoring and early warning system; second, constructing windbreaks along railway lines; and third, limiting train speed. Germany's Ril80704 guideline stipulates that comprehensive control and monitoring of crosswind safety across the entire railway network is necessary to ensure the safety and stability of trains operating under crosswinds. To this end, Germany has established a short-term strong crosswind forecasting model. Specifically, numerous anemometers are installed along the line, transmitting information about train type, track conditions, and wind speed to the control center via the track. The control center then issues instructions to adjust train speed. This system can forecast strong wind speeds two minutes in advance, ensuring sufficient time for trains to implement speed-limiting operations. France has constructed windbreaks on the TGV Mediterranean line and established a short-term spatial wind speed prediction and monitoring network along a continuous section of the line to enable automatic train deceleration in case of alarms. Since 2006, East Japan Railway Company has replaced all previously controlled areas with "early warning regulations" and introduced a "strong wind warning system" in 12 sections of three lines within the Tokyo metropolitan area. Windproof netting was installed on the Kamitsu Main Line to protect the trains from the effects of wind.

[0004] However, all three measures mentioned above have obvious drawbacks, and standards vary from country to country, lacking a unified international standard. Train speed limits refer to altering the maximum operating speed of trains under different wind conditions; the stronger the wind, the lower the train speed, until the train stops. Therefore, this severely impacts commuting rates and railway transport planning. Furthermore, setting these limits requires extensive real-vehicle testing under different wind conditions and track conditions to ensure their rationality, making it difficult to establish universally applicable normative documents. Constructing windproof facilities requires substantial funding and extensive real-vehicle testing before and after construction, and may result in inadequate or excessive windproofing in certain sections.

[0005] In summary, traditional control measures for trains operating in high wind environments are all passive, making it difficult to meet the diverse needs of windy environments and train speeds, and are also extremely costly. Therefore, it is of practical significance to implement active control measures that adjust relevant parameters based on the wind environment characteristics, train speed, and aerodynamic loads of the operating train to suppress the drag vortex intensity on the leeward side of the train, thereby reducing the leeward side pressure and achieving proactive control of train safety in high wind environments.

[0006] In existing technologies, there are schemes for controlling the crosswind effect of high-speed trains. These schemes create a novel microstructure surface by locally adding strip structures to the outer surface of the top of the train's lead car. This controls the boundary layer flow of the high-speed train under crosswind conditions, achieving interference control of large-scale separated vortices. It effectively suppresses flow separation phenomena occurring in the transition zone between the train's windward side and the top, thereby reducing lateral forces and overturning moments, further improving train operation safety and stability. However, this scheme focuses on the microscale, and its anti-overturning principle is to suppress flow separation phenomena at the top of the train, which differs from the "vortex-suppressing" method involved in this invention.

[0007] In existing technologies, there are also solutions for crosswind-resistant telescopic wings on high-speed trains. These solutions provide a high-speed train crosswind-resistant telescopic wing comprising at least one pair of wings positioned on both sides of the train body. When crosswind resistance is required, the wing on the windward side rotates 180 degrees, generating downward pressure on the windward side. This pressure, combined with the lift generated by the wing on the leeward side, creates a greater resistance moment, enhancing the resistance to crosswinds and improving the high-speed train's ability to withstand crosswinds. However, this method relies on the anti-overturning moment generated by the lifting wing itself. The anti-overturning principle is based on the asymmetric lift generated by the shape of the equipment under crosswind conditions, which differs from the method of controlling the train's own overturning moment in this invention. Summary of the Invention

[0008] The purpose of this invention is to address the problems existing in the background technology mentioned above by providing a solution based on the concept of eddy current generators. This solution uses eddy current generators to actively intervene in and control the flow field in the near-body region of a train. By analyzing and comparing the aerodynamic indicators of the original train with those of the eddy current generator control technology, a reasonable design position and parameters for the eddy current generator technology that can effectively improve the safety of train operation in windy environments can be obtained.

[0009] To achieve the above objectives, the present invention provides a vortex control method to improve train operation safety in windy conditions. When a train encounters a crosswind, the side of the train opposite to the crosswind is the windward side, and the side of the train away from the crosswind is the leeward side. Through a vortex generator located on the leeward side of the train's roof, a small-scale directional vortex is generated under the crosswind. The directional vortex develops downstream to the leeward side and is sucked into a large-scale drag vortex on the leeward side of the train, reducing the intensity of the drag vortex, increasing the pressure on the leeward side of the train, and reducing the lateral force and overturning moment of the train.

[0010] Furthermore, within certain limits, the higher the height of the eddy current generator, the better it is to reduce lateral forces and overturning moments.

[0011] Furthermore, the eddy current generators on both sides are retracted when the train is running normally, and the eddy current generator on the windward side is retracted when the train encounters crosswinds.

[0012] Furthermore, the angle of the vortex generator is adjusted according to the wind direction to minimize the overturning moment experienced by the train.

[0013] The present invention also provides a vortex control device to improve the safety of train operation in windy conditions. The device uses the method described above and includes multiple vortex generators installed on the top surface of the train. The vortex generators are arranged in two sets, arranged in a linear array along the longitudinal direction of the top surface of the train and symmetrically distributed with respect to the longitudinal section of the train. When encountering crosswinds, one set of vortex generators on the leeward side extends out of the top surface of the train, while the other set of generators on the windward side retracts into the top surface of the train.

[0014] Furthermore, the top surface of the train is provided with an installation slot, which is elongated and matches the eddy current generator. The installation slot and the eddy current generator are arranged in a one-to-one correspondence. A lifting drive mechanism is provided below the installation slot, which is used to drive the eddy current generator to extend and retract relative to the installation slot.

[0015] Furthermore, when the eddy current generator is retracted into the mounting slot, the top surface of the eddy current generator seals the mounting slot to maintain the aerodynamic integrity of the train's roof.

[0016] Furthermore, an angle adjustment mechanism is provided below the mounting slot. The angle adjustment mechanism includes a rotary drive unit and a rotary shaft. The rotary shaft is rotatably mounted on a lifting platform. The rotary drive unit is mounted on the lifting platform and is connected to the rotary shaft in a transmission connection. The end of the eddy current generator is connected to the rotary shaft to adjust the angle as the rotary shaft rotates. The lifting platform is connected to the lifting drive mechanism.

[0017] Furthermore, the eddy current generator maintains an angle consistent with the mounting slot during the lifting and lowering process, and after the eddy current generator extends out of the mounting slot, it is rotated and adjusted to a preset angle.

[0018] Furthermore, the eddy current generator is a blade type, a Wheeler type, or a wedge type.

[0019] The above-described solution of the present invention has the following beneficial effects:

[0020] The vortex control method and device for improving train operation safety in windy environments provided by this invention starts from the idea of ​​actively intervening in the vortex structure interference of the flow field in the near-body area of ​​the train. It realizes active control of train operation safety in windy environments through vortex generators on the top surface of the train. It breaks through the traditional passive control measures research thinking for train operation safety in windy environments and provides a new research idea for active control of train operation safety. At the same time, the control effect of the vortex generator arrangement scheme on train safety also provides a valuable reference for future research on active control technology for train operation safety using similar vortex generator control methods.

[0021] Other beneficial effects of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the leeward vortex structure of a train without or without an vortex generator in this invention.

[0023] Figure 2 This is a three-dimensional schematic diagram (single group) of the eddy current generator arrangement in this invention;

[0024] Figure 3 A top view of the arrangement of eddy current generators in this invention (single group);

[0025] Figure 4 This is a schematic diagram showing three different heights of the eddy current generator in this invention;

[0026] Figure 5 This is a schematic diagram of the mounting platform setup in this invention. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0028] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0029] It should also be noted that the illustrations provided in the following embodiments are merely schematic representations of the basic concept of this disclosure. The drawings only show components relevant to this disclosure and are not drawn according to the actual number, shape, and size of the components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex. Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0030] This invention provides a vortex control method to improve train operation safety in windy conditions, utilizing multiple vortex generators on the top surface of the train. When a train encounters a crosswind, the side of the train opposite the crosswind is the windward side, and the side away from the crosswind is the leeward side. Dividing the train into two parts using its longitudinal profile, the vortex generators are located on the top surface of the train on the leeward side. Under crosswind conditions, the vortex generators themselves generate small-scale flow vortices, such as... Figure 1As shown, the energetic, high-turbulence-intensity flow vortex will develop downstream on the leeward side and be sucked into the large-scale drag vortex on the leeward side of the train, thereby reducing the intensity of the drag vortex, increasing the pressure on the leeward side of the train, reducing the lateral force and overturning moment of the train, and achieving effective active control of train safety.

[0031] Understandably, this scheme employs a "vortex-suppressing-vortex" approach, reducing the intensity of drag vortices by generating small-scale flow vortices. This differs from existing technologies that add strip structures to the outer surface of the top of the high-speed train's lead car. Existing technologies use strip structures to form novel microstructure surfaces for high-speed trains, controlling boundary layer flow under crosswind conditions and effectively suppressing flow separation between the windward side and the top transition zone. This reduces lateral forces and overturning moments. The scheme focuses on the microscale, and its anti-overturning principle is based on suppressing flow separation at the train's top.

[0032] In this embodiment, several vortex generators at different heights were installed on the top surface of the train. Based on computational fluid dynamics, the aerodynamic parameters of the train with different vortex generator heights under windy conditions were numerically simulated and compared with the aerodynamic performance of the original train without vortex generators. Finally, the optimal vortex generator design scheme that can significantly improve the aerodynamic parameters of the train under windy conditions was obtained.

[0033] specific Figure 2 and Figure 3 As shown, this illustrates the installation location of rectangular eddy current generators on a train with a body height H = 3.70 m. The eddy current generators are rectangular and arranged in a linear array on the top surface of the train. Each eddy current generator has a preset angle (oblique angle) with the train's direction of travel (longitudinal section of the train). The eddy current generators are positioned on the leeward side of the train's top surface. The small-scale eddy structures they generate are injected into the main eddy (dragging eddy) on the leeward side of the train to reduce the eddy intensity on the leeward side, thereby increasing the leeward side pressure and reducing the lateral force and overturning moment.

[0034] To determine the optimal height of the eddy current generator to ensure the train achieves the best wind resistance and aerodynamic performance, Figure 4 This embodiment presents a comparative analysis of three height schemes for the eddy current generator. Here, h represents the boundary layer thickness at the top of the vehicle body in a wind field of 60 m / s with a 30° sideslip angle. The three schemes are: 0.4h height scheme one, h height scheme two, and 2h height scheme three, with the eddy current generator initially located at the longitudinal section of the train. It should be noted that... Figure 2 The eddy current generator shown corresponds to Figure 4 Option 3.

[0035] In this embodiment, when comparing vortex generators at three different heights, the common composite velocity from high-speed train wind tunnel tests was used as the research condition. The composite velocity was 60 m / s, and the sideslip angle was 30°. Computational fluid dynamics was used to obtain the key aerodynamic parameters of the train model using vortex generators at three different heights, and these parameters were compared with those of the original train model (the train without vortex generators). As shown in equations (1) to (4), the main aerodynamic parameters for safe train operation include the lateral force coefficient C. y Lift coefficient C z Overturning moment coefficient C Mxlee F y For lateral force, F z For lift, M xlee The aerodynamic overturning moment is denoted by . A is the cross-sectional area of ​​the train, and l is the reference length (here, the train height is taken as ). For the train model used in this embodiment, in its full-size configuration, its cross-sectional area A and train height H are 11.22m. 2 and 3.7 m, U s The synthesis rate is given by ρ, where ρ is the air density, taken as 1.225 kg / m³. 3 .

[0036]

[0037]

[0038]

[0039]

[0040] Table 1 shows the C values ​​of the trains in the three schemes compared to the original train. y C z and C Mxlee The comparison results (incremental percentage E) are defined as shown in equation (4), where C represents the key aerodynamic coefficient value of the three schemes, and C0 represents the value of the aerodynamic coefficient corresponding to C in the original train model.

[0041] Table 1. Comparison of Aerodynamic Performance of Different Vortex Generator Height Schemes

[0042] Eddy current generator height scheme Primitive Train Option 1 Option 2 Option 3 <![CDATA[C y (E)]]> \ -19.58％ -20.71％ -24.37％ <![CDATA[C z (E)]]> \ 49.20％ 54.26％ 47.78％ <![CDATA[C mxlee (E)]]> \ -9.50％ -9.98％ -15.97％

[0043] As shown in Table 1, the eddy current generator can significantly alter the aerodynamic performance of a train in crosswinds, and the height of the eddy current generator also affects C. y and C z The effects are different, therefore, taking C as an example. y and C z C, an indicator reflecting the comprehensive effect of the effect MxleeThe following analysis was conducted to determine the impact of different eddy current generator height schemes on train safety. It can be seen that when scheme three (2h height) is used, train C... Mxlee This reduces the impact by 15.97%, effectively controlling the safety of the intermediate car in windy conditions. It's understandable that, within certain limits, a higher eddy current generator is more beneficial for reducing lateral forces and overturning moments.

[0044] Therefore, this embodiment, based on existing technological conditions where wind control measures for trains mainly involve passive measures such as speed limits and the construction of windproof facilities along railway lines in windy areas, adopts an active intervention approach that interferes with the vortex structure of the flow field near the train's body to achieve active control of train safety in windy environments. Simultaneously, three vortex generator height scheme models for leeward vortex control of trains were established, and based on a series of numerical simulation results, the effectiveness of these three vortex generator height scheme models in improving train safety in windy environments was evaluated, resulting in the final arrangement scheme of the train vortex generators. This approach breaks through the traditional passive control measures research mindset for train safety in windy environments, providing a new research approach for active control of train operation safety. Furthermore, the control effect of the proposed vortex generator arrangement scheme on train safety provides valuable reference for future research on active control technologies for train operation safety using similar vortex generator control methods.

[0045] Considering that crosswinds may blow towards the train body from the left or right side at different angles during actual train operation, this embodiment employs two symmetrically arranged sets of vortex generators, distributed symmetrically with respect to the train's longitudinal profile. The vortex generators on both sides can generate small-scale flow vortices or retract and become inactive, thus adapting to the lateral forces and overturning moments resisted when crosswinds switch between the left and right sides of the train. An installation slot, elongated and matching the vortex generator, can be created on the train's roof, with each slot corresponding to a different vortex generator. A lifting drive mechanism is also provided below the installation slot, which drives the vortex generator to extend out of the installation slot to generate small-scale flow vortices or retract and become inactive.

[0046] Furthermore, for crosswinds blowing towards the train at different angles, the vortex generator should have an optimal angle to maximize the overturning moment coefficient. This optimal value can also be obtained through numerical simulation using computational fluid dynamics. As a preferred embodiment, this example further adjusts the angle of the vortex generator according to wind direction adaptability. Once the train's wind direction sensor detects and confirms the wind direction, the vortex generator on the leeward side rises and adjusts to the optimal angle corresponding to the wind direction, minimizing the overturning moment experienced by the train and better ensuring the safety of train operation when encountering crosswinds.

[0047] Based on the same inventive concept, this embodiment also provides a vortex control device to improve train operation safety in windy conditions, including multiple vortex generators installed on the top surface of the train. The vortex generators are generally rectangular plate-shaped structures; in other embodiments, blade-type vortex generators of other shapes can be used, such as triangular and trapezoidal, or Wheeler-type or wedge-shaped vortex generators. The vortex generators are arranged in a longitudinal linear array along the top surface of the train. Based on the difference between left-side and right-side crosswinds, this embodiment uses two sets of vortex generators arranged in a longitudinal linear array along the top surface of the train. When encountering a crosswind, the vortex generators on the leeward side extend out of the top surface of the train and generate small-scale directional vortices, while the vortex generators on the windward side retract into the top surface of the train and have no effect.

[0048] Specifically, the device also includes an installation slot on the top surface of the train. The installation slot is elongated and matches the eddy current generator, with each slot and eddy current generator arranged in a one-to-one correspondence. A lifting drive mechanism is installed below the installation slot, which can be in the form of a cylinder, electric actuator, etc. The lifting drive mechanism drives the eddy current generator to extend out of the installation slot to generate small-scale directional eddies, or retracts it without producing any effect. Based on the aforementioned numerical simulation examples, the lifting drive mechanism can also control the lifting height of the eddy current generator, allowing for height adaptive adjustments to different intensities of crosswinds, or adjusting the eddy current generator to a safe height when it is about to cross a height restriction area.

[0049] It should be noted that the thickness of the mounting groove should ideally be precisely matched with that of the eddy current generator, i.e., slightly larger than the thickness of the eddy current generator, so that after the eddy current generator is retracted, the upper edge (i.e., the top surface) of the eddy current generator can seal the mounting groove as much as possible, thereby maintaining the aerodynamic integrity of the train's top surface and ensuring the aerodynamic effect during normal train operation.

[0050] Meanwhile, for crosswinds blowing towards the train at different angles, this embodiment further includes an angle adjustment mechanism for the eddy current generator, which includes a rotary drive unit and a rotary shaft. The rotary drive unit can be in the form of a servo motor, etc. The rotary shaft is rotatably mounted on a lifting platform, and the servo motor is mounted on the lifting platform and driven by the rotary shaft. The rotary shaft is driven to rotate by the servo motor. The end of the eddy current generator is connected to the rotary shaft and can adjust its angle as the rotary shaft rotates. The lifting platform can be located in the cavity below the mounting slot and connected to the lifting drive mechanism to drive the overall lifting.

[0051] Considering that the eddy current generator needs to be rotated and adjusted, this embodiment sets the mounting slot at a fixed angle to the longitudinal section of the train. The eddy current generator maintains the same angle as the mounting slot during lifting and lowering, allowing for smooth lifting and lowering along the slot and ensuring the aerodynamic integrity of the train's roof after retraction. When the eddy current generator extends out of the mounting slot, it can rotate to a preset angle with the rotating shaft under the drive of a servo motor, optimizing the overturning moment coefficient and better ensuring the safety of the train when encountering crosswinds. When the eddy current generator needs to be retracted, it first rotates to the same angle as the mounting slot and then retracts via the lifting drive mechanism.

[0052] Alternatively, a rotating mounting slot method can be considered. A rotating platform is installed on the train's roof, with the mounting slot located on it. A lifting and driving mechanism is positioned below the rotating platform and rotates synchronously with it. The rotating platform is considered part of the train's roof surface, ensuring its integrity when the eddy current generator is retracted into the mounting slot. When eddy current control is needed, the rotating platform rotates the mounting slot to a preset angle. Simultaneously, the eddy current generator is driven by the lifting and driving mechanism to extend out of the mounting slot, ultimately aligning at a preset angle on the train's roof surface, generating small-scale eddies to reduce eddy current intensity on the leeward side of the train.

[0053] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vortex control method for improving train operation safety in high wind environments, characterized in that, When a train encounters a crosswind, the side of the train opposite to the crosswind is the windward side, and the side of the train away from the crosswind is the leeward side. Through the vortex generator on the top surface of the train located on the leeward side, small-scale directional vortices are generated under the crosswind. The directional vortices develop downstream on the leeward side and are sucked into the large-scale drag vortex on the leeward side of the train, reducing the intensity of the drag vortex, increasing the pressure on the leeward side of the train, and reducing the lateral force and overturning moment of the train. Within certain limits, a higher eddy current generator is more beneficial for reducing lateral forces and overturning moments; the height of the eddy current generator is set to... , The thickness of the boundary layer on top of the vehicle body in a wind field with a sideslip angle of 30° and a wind speed of 60 m / s. When the train is running normally, the eddy current generators on both sides are retracted. When the train encounters crosswinds, the eddy current generator on the windward side is retracted. A vortex control device for improving train operation safety in windy conditions is adopted. The vortex control device includes multiple vortex generators installed on the top surface of the train. The vortex generators are arranged in two sets, arranged in a linear array along the longitudinal direction of the top surface of the train, and are symmetrically distributed with respect to the longitudinal section of the train. When encountering crosswinds, the set of vortex generators on the leeward side extends out of the top surface of the train, and the set of generators on the windward side retracts into the top surface of the train. The top surface of the train is provided with an installation slot, which is long and narrow and matches the eddy current generator. The installation slot and the eddy current generator are arranged in a one-to-one correspondence. A lifting drive mechanism is provided below the installation slot, which is used to drive the eddy current generator to extend and retract relative to the installation slot. When the eddy current generator is retracted into the mounting slot, the top surface of the eddy current generator seals the mounting slot to maintain the aerodynamic integrity of the train's roof. Below the mounting slot, an angle adjustment mechanism is also provided. The angle adjustment mechanism includes a rotary drive and a rotary shaft. The rotary shaft is rotatably mounted on a lifting platform. The rotary drive is mounted on the lifting platform and is drively connected to the rotary shaft. The end of the eddy current generator is connected to the rotary shaft to adjust the angle as the rotary shaft rotates. The lifting platform is connected to the lifting drive mechanism. The eddy current generator maintains the same angle as the mounting slot during the lifting process. After the eddy current generator extends out of the mounting slot, it rotates and adjusts to a preset angle.

2. The vortex control method for improving train operation safety in high wind environments according to claim 1, characterized in that, The angle of the eddy current generator is adjusted according to the wind direction to minimize the overturning moment on the train.

3. The vortex control method for improving train operation safety in high wind environments according to claim 1, characterized in that, The eddy current generator is of blade type, Wheeler type, or wedge type.

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