Design method of aerodynamic effect relieving system and relieving system

Abstract

The invention relates to a design method of an aerodynamic effect relieving system and the relieving system. The design method comprises the following steps that the opening area of each communicating hole and the distance between every two adjacent communicating holes in the length direction of a tunnel are determined based on various parameters of a train and the tunnel; determining the shape and position of each communication hole according to the opening area of each communication hole and the distance between two adjacent communication holes; and a plurality of communicating holes used for communicating the on-rail space and the under-rail space of the tunnel are formed in the length direction of the tunnel at intervals according to the shape and the position of each communicating hole. According to the design method of the aerodynamic effect relieving system and the relieving system, the problem that the relieving effect of the aerodynamic effect is poor when the clearance area above the rail surface of the high-speed rail shield tunnel is limited is solved.

Description

Technical Field

[0001] This invention relates to the field of tunnel technology, and in particular to a design method and a mitigation system for aerodynamic effects. Background Technology

[0002] When a high-speed train enters a smaller cross-section (shield tunnel) from a larger cross-section (mining method or cut-and-cover method tunnel), the space narrows, creating a high-pressure compression wave in front of the train. Simultaneously, a negative pressure zone forms at the rear of the train, generating an expansion wave. When the compression wave reflects within the tunnel and superimposes with the subsequent expansion wave, it causes a sudden change in local tunnel pressure, resulting in transient pressure. This transient pressure can lead to adverse effects such as increased train drag, aerodynamic imbalance, and reduced passenger comfort.

[0003] To mitigate the aerodynamic effects of trains, the "High-Speed ​​Railway Design Code" specifies requirements for the clearance area above the rail surface corresponding to the design speed. However, in reality, due to the limited clearance area above the rail surface in high-speed railway shield tunnels, the aerodynamic effect mitigation is relatively poor. Summary of the Invention

[0004] The main objective of this invention is to propose a design method and system for mitigating aerodynamic effects, aiming to solve the problem of poor aerodynamic effect mitigation when the clearance area above the track surface of a high-speed railway shield tunnel is limited.

[0005] To achieve the above objectives, the present invention proposes a design method for an aerodynamic effect mitigation system, comprising the following steps:

[0006] The opening area of ​​each connecting hole and the spacing between two adjacent connecting holes along the tunnel length direction are determined based on various parameters of the train and the tunnel.

[0007] The shape and position of each connecting hole are determined based on the opening area of ​​each connecting hole and the distance between two adjacent connecting holes.

[0008] Based on the shape and location of each connecting hole, multiple connecting holes are arranged at intervals along the length of the tunnel to connect the track space and the track space.

[0009] According to some embodiments of the present invention, determining the opening area of ​​each connecting hole and the spacing between two adjacent connecting holes along the tunnel length direction based on various parameters of the train and the tunnel includes:

[0010] Determine the standard clearance area on the track based on the train's design speed;

[0011] Obtain the initial opening area and initial spacing of each connecting hole;

[0012] The effective cross-sectional clearance area is obtained based on various parameters of the train and tunnel, the standard clearance area on the track, and the initial opening area and initial spacing of each connecting hole.

[0013] The effective clearance area of ​​the cross section is compared with the standard clearance area on the track, and the opening area and spacing of each connecting hole are adjusted according to the comparison results until the difference between the standard clearance area on the track and the effective clearance area of ​​the cross section is less than a preset threshold.

[0014] The current opening area and the current spacing are used as the opening area of ​​each connected hole and the spacing between two adjacent connected holes.

[0015] According to some embodiments of the present invention, obtaining the effective cross-sectional clearance area based on various parameters of the train and tunnel, the standard clearance area on the track, and the initial opening area and initial spacing of each connecting hole includes:

[0016] The first characteristic value is obtained based on the train model, train formation parameters, train design speed, train speed and time curve, train sealing performance parameters, tunnel length, and tunnel cross-sectional shape and tunnel cross-sectional layout parameters corresponding to the track clearance area.

[0017] The second characteristic value is obtained based on the train model, train formation parameters, train design speed, train speed and time curve, train sealing performance parameters, tunnel length, actual tunnel cross-sectional shape, actual tunnel cross-sectional layout parameters, and the initial opening area and initial spacing of each connecting hole.

[0018] The equivalent coefficient of the aerodynamic effect mitigation of the under-rail space and the under-rail clearance area is calculated based on the first characteristic value, the second characteristic value, the standard clearance area on the track, the actual clearance area on the track, and the actual area under the track.

[0019] The effective net area of ​​the cross section is calculated based on the equivalent coefficient, the actual net area on the track, and the actual area under the track.

[0020] According to some embodiments of the present invention, obtaining the first characteristic value based on the train model, train formation parameters, train design speed, train speed-time curve, train sealing performance parameters, tunnel length, and the tunnel cross-sectional shape and tunnel cross-sectional layout parameters corresponding to the track clearance area includes:

[0021] The first three-dimensional model is established based on the train model, train formation parameters, train design speed, tunnel length, and the tunnel cross-sectional shape and layout parameters corresponding to the track clearance area.

[0022] Based on the first three-dimensional model, the train speed and time curves, and the train sealing performance parameters, aerodynamic simulation tests were conducted under multiple working conditions, including a single vehicle passing through a tunnel and two vehicles meeting at different locations in the tunnel, to obtain the first transient pressure amplitude, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train in the tunnel.

[0023] The first characteristic value is calculated based on the first transient pressure amplitude inside the tunnel, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train.

[0024] According to some embodiments of the present invention, calculating the first characteristic value based on the first transient pressure amplitude inside the tunnel, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train includes:

[0025] The extreme value normalization method is used to normalize the amplitude of the first transient pressure, the amplitude of the first micro-pressure wave, and the rate of change of the first internal and external pressure of the train in the tunnel, so as to obtain the first normalization index, the second normalization index, and the third normalization index.

[0026] The first weight value, the second weight value, and the third weight value are determined using the analytic hierarchy process (AHP), and the sum of the first weight value, the second weight value, and the third weight value is set to 1.

[0027] The first normalized index, the second normalized index, and the third normalized index are weighted and calculated based on the first weight value, the second weight value, and the third weight value to obtain the first feature value.

[0028] According to some embodiments of the present invention, obtaining the second characteristic value based on the train model, train formation parameters, train design speed, train speed-time curve, train sealing performance parameters, tunnel length, actual tunnel cross-sectional shape, actual tunnel cross-sectional layout parameters, and the initial opening area and initial spacing of each connecting hole includes:

[0029] A second three-dimensional model is established based on the train model, train formation parameters, train design speed, tunnel length, actual tunnel cross-sectional shape, and actual tunnel cross-sectional layout parameters.

[0030] Based on the initial opening area and initial spacing of each connecting hole, multiple connecting holes are set in the tunnel model of the second three-dimensional model to obtain the updated second three-dimensional model.

[0031] Based on the second three-dimensional model, the train speed and time curves, and the train sealing performance parameters, aerodynamic simulation tests were conducted under multiple working conditions, including a single vehicle passing through a tunnel and two vehicles meeting at different locations in the tunnel, to obtain the second transient pressure amplitude, the second micro-pressure wave amplitude, and the second internal and external pressure change rate of the train in the tunnel.

[0032] The second characteristic value is calculated based on the second transient pressure amplitude inside the tunnel, the second micro-pressure wave amplitude, and the second internal and external pressure change rate of the train.

[0033] According to some embodiments of the present invention, the method of arranging multiple connecting holes at intervals along the tunnel length direction to connect the track space and the track sub-space of the tunnel according to the shape and position of each connecting hole includes:

[0034] Based on the location of each connecting hole, multiple evacuation staircases leading to the evacuation passage under the track are arranged at intervals along the length of the tunnel.

[0035] The connecting holes are made on the side walls of each evacuation staircase according to their shape and location, so that the space above the track is connected to the evacuation passage below the track.

[0036] According to some embodiments of the present invention, after the plurality of connecting holes for connecting the track space and the track subspace of the tunnel are arranged at intervals along the tunnel length direction according to the shape and position of each connecting hole, the method further includes:

[0037] Ventilation louver valves, which can be controlled by a controller, are installed at each of the aforementioned connecting holes, so that each ventilation louver valve blocks the corresponding connecting hole.

[0038] In addition, the present invention also provides an aerodynamic effect mitigation system, including a plurality of connecting holes opened on the tunnel to connect the space above the track and the space below the track. The plurality of connecting holes are arranged at intervals along the length of the tunnel, and the shape and position of each connecting hole are determined by the design method described in any of the above.

[0039] According to some embodiments of the present invention, the system further includes a controller and a plurality of ventilation louvers, wherein the plurality of ventilation louvers are configured to correspond one-to-one with the plurality of connecting holes to block each of the connecting holes, and the plurality of ventilation louvers are electrically connected to the controller, which is used to control the plurality of ventilation louvers to close in the event of a fire.

[0040] The present invention has at least the following beneficial effects:

[0041] In this invention, the design method of the aerodynamic effect mitigation system includes the following steps: determining the opening area of ​​each connecting hole and the spacing between two adjacent connecting holes along the tunnel length direction based on various parameters of the train and the tunnel; determining the shape and position of each connecting hole according to the opening area of ​​each connecting hole and the spacing between two adjacent connecting holes; and arranging multiple connecting holes at intervals along the tunnel length direction to connect the track space and the track space below the tunnel according to the shape and position of each connecting hole. This invention connects the track space and the track space below the tunnel by arranging multiple connecting holes at intervals. When the train is running, the compression wave in front of the train can partially enter the connecting holes and be released in the track space below the track, reducing the intensity of the compression wave. At the same time, the negative pressure behind the train draws in air from the track space below the track through the connecting holes, reducing the negative pressure value. This reduces the superposition and interference effects of the two waves in the tunnel, thus mitigating the aerodynamic effects of the train when the track clearance area of ​​the shield tunnel is limited. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A schematic diagram illustrating the principle of an aerodynamic effect mitigation system provided in an embodiment of the present invention.

[0044] Figure 2 This is a cross-sectional view of a shield tunnel;

[0045] Figure 3 for Figure 2 A schematic diagram of the central evacuation staircase and connecting openings;

[0046] Figure 4 This is a cross-sectional view of a shield tunnel according to another embodiment of the present invention;

[0047] Figure 5 This is a flowchart illustrating the first embodiment of the design method of the present invention;

[0048] Figure 6 This is a flowchart illustrating the second embodiment of the design method of the present invention;

[0049] Figure 7 This is a flowchart illustrating the third embodiment of the design method of the present invention;

[0050] Figure 8 This is a flowchart illustrating the fourth embodiment of the design method of the present invention;

[0051] Figure 9This is a flowchart illustrating the fifth embodiment of the design method of the present invention;

[0052] Figure 10 This is a flowchart illustrating the sixth embodiment of the design method of the present invention;

[0053] Figure 11 This is a flowchart illustrating the seventh embodiment of the design method of the present invention;

[0054] Figure 12 This is a flowchart illustrating the eighth embodiment of the design method of the present invention.

[0055] Explanation of reference numerals in the attached figures:

[0056] 100 - Aerodynamic effect mitigation system; 1 - Connecting hole; 2 - Ventilation louver valve; 200 - Track space; 300 - Track space; 310 - Track evacuation passage; 400 - Evacuation staircase; 500 - Train; 600 - Track. Detailed Implementation

[0057] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0059] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0060] This invention provides a design method and a mitigation system for aerodynamic effects. Figures 1 to 12 This invention provides a design method for an aerodynamic effect mitigation system and specific embodiments of the mitigation system.

[0061] like Figures 1 to 4 As shown, an embodiment of the present invention provides an aerodynamic effect mitigation system 100, including a plurality of connecting holes 1 opened on a tunnel to connect the track space 200 and the track space 300. The plurality of connecting holes 1 are arranged at intervals along the length of the tunnel, and the shape and position of each connecting hole 1 are determined by the design method of the aerodynamic effect mitigation system 100.

[0062] In this invention, by arranging multiple connecting holes 1 at intervals on the tunnel, the space above the track 200 and the space below the track 300 are connected. When the train 500 is running, the compression wave in front of the train 500 can partially enter the connecting holes 1 and be released in the space below the track 300, reducing the intensity of the compression wave. At the same time, the negative pressure behind the train 500 draws in air from the space below the track 300 through the connecting holes 1, reducing the negative pressure value. This reduces the superposition and interference effect of the two waves in the tunnel, and alleviates the aerodynamic effect of the train 500 when the clearance area above the track in the shield tunnel is limited.

[0063] It should be noted that the track-under space 300 includes a track-under evacuation passage 310. The tunnel is a high-speed railway single-bore double-track shield tunnel. Two parallel tracks 600 are arranged inside the tunnel, and multiple evacuation staircases 400 leading to the track-under evacuation passage 310 are spaced apart between the two tracks 600. In this embodiment, as shown... Figure 2 As shown, the connecting hole 1 is formed on the side wall of each of the evacuation staircases 400, so as to connect the track space 200 with the track evacuation passage 310. Furthermore, the connecting hole 1 is formed on both side walls of the evacuation staircase 400, and the two connecting holes 1 are symmetrically arranged about the length direction of the tunnel.

[0064] In another embodiment, such as Figure 4 As shown, each of the connecting holes 1 is spaced apart at the top of the evacuation channel 310 under the track, so that the space on the track 200 is connected to the evacuation channel 310 under the track.

[0065] Because the tunnel has a connecting hole 1 for connecting the track space 200 and the track space 300, in the event of a fire, dense smoke can spread from the connecting hole 1 to the track space 300. Therefore, in some embodiments, such as... Figure 3As shown, the aerodynamic effect mitigation system 100 also includes a controller and multiple ventilation louver valves 2. Each ventilation louver valve 2 is configured to correspond one-to-one with one of the multiple connecting holes 1 to block each connecting hole 1. Each ventilation louver valve 2 is electrically connected to the controller, which is used to control the closure of the multiple ventilation louver valves 2 in case of a fire. This configuration, by blocking each connecting hole 1 with the multiple ventilation louver valves 2, allows the controller to open each ventilation louver valve 2 under normal operating conditions and close each ventilation louver valve 2 under fire conditions. This enables the connecting holes 1 to mitigate the aerodynamic effects of the train 500 under normal operating conditions and prevents dense smoke from spreading to the under-track space 300 through the connecting holes 1 in case of a fire.

[0066] It should be noted that the ventilation louver valve 2 is made of fire-resistant material. The controller can control the opening degree of each ventilation louver valve 2, thereby adjusting the airflow and thus mitigating the aerodynamic effects on the train 500.

[0067] Those skilled in the art will understand that the above-described structure does not constitute a limitation on the aerodynamic effect mitigation system 100, and may include more or fewer components than described above, or combine certain components, or have different component arrangements.

[0068] like Figure 5 As shown, this embodiment of the invention provides a design method for an aerodynamic effect mitigation system 100, comprising the following steps:

[0069] Step S10: Determine the opening area of ​​each connecting hole 1 and the spacing between two adjacent connecting holes 1 in the tunnel length direction based on the parameters of the train 500 and the tunnel.

[0070] It should be noted that the parameters of the train 500 include at least the train model, train formation parameters, train design speed, train speed-time curve, and train sealing performance parameters. Different train models have different three-dimensional dimensions, and the train formation parameters include the number of carriages.

[0071] It should be noted that the parameters of the tunnel include at least the tunnel length, tunnel cross-sectional shape, and tunnel cross-sectional layout. The tunnel cross-sectional layout includes at least the spatial division and dimensional boundaries of the track space 200 and the track-under space 300.

[0072] Step S20: Determine the shape and position of each connecting hole 1 based on the opening area of ​​each connecting hole 1 and the distance between two adjacent connecting holes 1.

[0073] Step S30: According to the shape and position of each connecting hole 1, multiple connecting holes 1 are arranged at intervals along the tunnel length direction to connect the track space 200 and the track space 300 of the tunnel.

[0074] In this invention, the design method of the aerodynamic effect mitigation system 100 includes the following steps: determining the opening area of ​​each connecting hole 1 and the spacing between two adjacent connecting holes 1 along the tunnel length direction based on various parameters of the train 500 and the tunnel; determining the shape and position of each connecting hole 1 according to the opening area of ​​each connecting hole 1 and the spacing between two adjacent connecting holes 1; and arranging multiple connecting holes 1 at intervals along the tunnel length direction to connect the track space 200 and the track space 300 of the tunnel according to the shape and position of each connecting hole 1. This invention connects the track space 200 and the track space 300 by arranging multiple connecting holes at intervals on the tunnel. When the train 500 is running, the compression wave in front of the train 500 can partially enter the connecting holes 1 and be released in the track space 300, reducing the intensity of the compression wave. At the same time, the negative pressure behind the train 500 draws in air from the track space 300 through the connecting holes 1, reducing the negative pressure value. This reduces the superposition and interference effects of the two waves in the tunnel, thus mitigating the aerodynamic effects of the train 500 when the track clearance area of ​​the shield tunnel is limited.

[0075] refer to Figure 6 , Figure 6 This is a flowchart illustrating the second embodiment of the design method of the present invention.

[0076] Based on the first embodiment described above, the design method of this embodiment includes the following in step S10:

[0077] Step S11: Determine the standard clearance area on the track based on the train design speed.

[0078] It should be noted that after obtaining the train design speed, the required track clearance area corresponding to the train design speed should be found in the "High-Speed ​​Railway Design Code".

[0079] Step S12: Obtain the initial opening area and initial spacing of each connecting hole 1.

[0080] It should be noted that, under normal circumstances, the opening area of ​​each of the connecting holes 1 is consistent, and the spacing between two adjacent connecting holes 1 is consistent. Therefore, the initial opening area of ​​each connecting hole 1 is consistent, and the initial spacing between two adjacent connecting holes 1 is consistent. The initial opening area and initial spacing of each connecting hole 1 can be determined based on the designer's experience.

[0081] Step S13: Based on the parameters of the train 500 and the tunnel, the standard clearance area on the track, and the initial opening area and initial spacing of each connecting hole 1, the effective clearance area of ​​the cross section is obtained.

[0082] Step S14: Compare the effective clearance area of ​​the cross section with the standard clearance area on the track, and adjust the opening area and spacing of each connecting hole 1 according to the comparison result until the difference between the standard clearance area on the track and the effective clearance area of ​​the cross section is less than a preset threshold.

[0083] It should be noted that the effective clearance area of ​​the cross section is smaller than the standard clearance area on the track. By adjusting the opening area and spacing of each connecting hole 1, the effective clearance area of ​​the cross section is increased, so that the value of the effective clearance area of ​​the cross section gradually approaches the standard clearance area on the track, until the difference between the standard clearance area on the track and the effective clearance area of ​​the cross section is less than a preset threshold.

[0084] It should be noted that the opening area and spacing of each connecting hole 1 are not linearly related to the effective net area of ​​the cross section. The designer makes adjustments to the opening area and spacing of each connecting hole 1 based on experience and the change in the effective net area of ​​the cross section after adjustment.

[0085] It should be noted that the preset threshold can be set according to actual needs.

[0086] Step S15: Use the current opening area and the current spacing as the opening area of ​​each connecting hole 1 and the spacing between two adjacent connecting holes 1.

[0087] It should be noted that when the difference between the standard clearance area on the track and the effective clearance area of ​​the cross section is less than a preset threshold, the current opening area and the current spacing are used as the opening area of ​​each connecting hole 1 and the spacing between two adjacent connecting holes 1.

[0088] refer to Figure 7 , Figure 7 This is a flowchart illustrating the third embodiment of the design method of the present invention.

[0089] Based on the second embodiment described above, the design method of this embodiment includes the following in step S13:

[0090] Step S131: Obtain the first characteristic value based on the train model, train formation parameters, train design speed, train speed-time curve, train sealing performance parameters, tunnel length, and the tunnel cross-sectional shape and layout parameters corresponding to the track clearance area.

[0091] It should be noted that the first characteristic value is the characteristic value when the tunnel cross-section is based on the track clearance area.

[0092] Step S132: Obtain the second characteristic value based on the train model, train formation parameters, train design speed, train speed and time curve, train sealing performance parameters, tunnel length, actual tunnel cross-sectional shape, actual tunnel cross-sectional layout parameters, and the initial opening area and initial spacing of each connecting hole 1.

[0093] It should be noted that the second feature value is the feature value corresponding to the actual cross-section of the tunnel after setting the connecting hole 1 according to the initial opening area and initial spacing.

[0094] Step S133: Calculate the equivalence coefficient between the aerodynamic effect mitigation of the under-track space and the under-track clearance area based on the first characteristic value, the second characteristic value, the standard clearance area on the track, the actual clearance area on the track, and the actual area under the track.

[0095] It should be noted that the actual cross-sectional layout parameters of the tunnel include the actual net clearance area above the track and the actual area below the track.

[0096] It should be noted that the equivalent coefficient is set as K, the first eigenvalue is set as T1, the second eigenvalue is set as T2, the standard clearance area on the track is set as S0, the actual clearance area on the track is set as S1, the actual area under the track is set as S2, and the formula for calculating the equivalent coefficient is:

[0097]

[0098] The equivalent coefficients can be calculated by substituting the above parameters into the calculation formula.

[0099] Step S134: Calculate the effective net area of ​​the cross section based on the equivalent coefficient, the actual net area on the track, and the actual area under the track.

[0100] It should be noted that the effective net area of ​​the cross-section is denoted as S, and the formula for calculating the effective net area of ​​the cross-section is:

[0101]

[0102] Substituting the above parameters into the calculation formula, the effective net area of ​​the cross-section can be calculated.

[0103] refer to Figure 8 , Figure 8 This is a flowchart illustrating the fourth embodiment of the design method of the present invention.

[0104] Based on the third embodiment described above, the design method of this embodiment includes the following in step S131:

[0105] Step S1311: Establish the first three-dimensional model based on the train model, train formation parameters, train design speed, tunnel length, and the tunnel cross-sectional shape and layout parameters corresponding to the track clearance area.

[0106] It should be noted that the first three-dimensional model includes the static structural three-dimensional model of train 500 and the static structural three-dimensional model of the tunnel corresponding to the standard clearance area on the track.

[0107] Step S1312: Under multiple working conditions, including a single vehicle passing through a tunnel and two vehicles meeting at different locations in the tunnel, an aerodynamic simulation test is conducted based on the first three-dimensional model, the train speed and time curve, and the train sealing performance parameters to obtain the first transient pressure amplitude, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train inside the tunnel.

[0108] It should be noted that the tunnel in this embodiment is a high-speed railway single-bore double-track shield tunnel with two parallel tracks arranged inside. At this time, there are working conditions where a single train passes through the tunnel and two trains travel towards each other and meet inside the tunnel.

[0109] It should be noted that, using the static three-dimensional structural model of train 500 and the tunnel as a carrier, during the aerodynamic simulation test, the dynamic motion core parameter of the train's speed and time curve is loaded. At the same time, dynamic working conditions such as single-vehicle passage and two-vehicle meeting at different positions in the tunnel are set, along with the train's sealing performance parameters. Through the aerodynamic simulation algorithm, the static three-dimensional structural model is made to realize the dynamic motion states of the train, such as speed change and meeting, in the simulation environment. This allows the aerodynamic interaction between the train and the tunnel during the dynamic motion process to obtain indicators such as the first transient pressure amplitude, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train in the tunnel.

[0110] It should be noted that the train sealing performance parameters include at least the car body airtightness depressurization time constant, which is the only core determining parameter of the train's first internal and external pressure change rate.

[0111] Step S1313: Calculate the first characteristic value based on the first transient pressure amplitude, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train inside the tunnel.

[0112] refer to Figure 9 , Figure 9 This is a flowchart illustrating the fifth embodiment of the design method of the present invention.

[0113] Based on the fourth embodiment described above, the design method of this embodiment includes the following in step S1313:

[0114] Step S13131: The extreme value normalization method is used to normalize the amplitude of the first transient pressure, the amplitude of the first micro-pressure wave, and the rate of change of the first internal and external pressure of the train in the tunnel, so as to obtain the first normalization index, the second normalization index, and the third normalization index.

[0115] It should be noted that the three values—the amplitude of the first transient pressure inside the tunnel, the amplitude of the first micro-pressure wave, and the rate of change of the first internal and external pressure of the train—have different dimensions and large differences in their numerical ranges. They need to be normalized first to eliminate the influence of dimensions. Since the extreme value normalization method is an existing technology, the specific detailed steps will not be elaborated.

[0116] Step S13132: Use the analytic hierarchy process (AHP) to determine the first weight value, the second weight value, and the third weight value, and set the sum of the first weight value, the second weight value, and the third weight value to 1.

[0117] It should be noted that the first weight value is set as x1, the second weight value as x2, and the third weight value as x3. Generally, the weights can be determined using the engineering experience method, based on the engineering experience of experts, setting x1=0.4, x2=0.3, and x3=0.3. The engineering experience method is more efficient. However, in this embodiment, the analytic hierarchy process is used to construct a judgment matrix by comparing the indicators pairwise. Then, through mathematical calculations (solving eigenvalues ​​and eigenvectors), the subjective judgments of the pairwise comparisons are transformed into quantified weight values. At the same time, it supports group decision-making, with multiple experts from different fields jointly constructing the judgment matrix. By integrating the opinions of multiple experts through the mean and weighted average, the subjective bias of a single expert is greatly reduced, making the weights more objective.

[0118] Step S13133: Perform a weighted calculation on the first normalized index, the second normalized index, and the third normalized index based on the first weight value, the second weight value, and the third weight value to obtain the first feature value.

[0119] It should be noted that the first normalization index is set as y1, the second normalization index is set as y2, and the third normalization index is set as y3. The formula for calculating the first eigenvalue is:

[0120]

[0121] The first characteristic value can be calculated by substituting the above parameters into the calculation formula.

[0122] refer to Figure 10 , Figure 10 This is a flowchart illustrating the sixth embodiment of the design method of the present invention.

[0123] Based on the third embodiment described above, the design method of this embodiment includes the following in step S132:

[0124] Step S1321: Establish a second three-dimensional model based on the train model, train formation parameters, train design speed, tunnel length, actual tunnel cross-sectional shape, and actual tunnel cross-sectional layout parameters.

[0125] It should be noted that the second three-dimensional model includes the static structural three-dimensional model of train 500 and the static structural three-dimensional model of the actual tunnel.

[0126] Step S1322: Based on the initial opening area and initial spacing of each connecting hole 1, set multiple connecting holes 1 in the tunnel model of the second three-dimensional model to obtain the updated second three-dimensional model.

[0127] It should be noted that the second 3D model needs to be updated each time the opening area and spacing of the connecting hole 1 are adjusted.

[0128] Step S1323: Under multiple working conditions, including a single vehicle passing through a tunnel and two vehicles meeting at different locations in the tunnel, an aerodynamic simulation test is conducted based on the second three-dimensional model, the train speed and time curve, and the train sealing performance parameters to obtain the second transient pressure amplitude, the second micro-pressure wave amplitude, and the second internal and external pressure change rate of the train inside the tunnel.

[0129] It should be noted that the specific methods for obtaining the second transient pressure amplitude, the second micro-pressure wave amplitude, and the second internal and external pressure change rate of the train inside the tunnel are the same as the method in step S1312 of the fourth embodiment.

[0130] Step S1324: Calculate the second characteristic value based on the second transient pressure amplitude, the second micro-pressure wave amplitude, and the second internal and external pressure change rate of the train inside the tunnel.

[0131] It should be noted that the specific method for obtaining the second feature value is the same as the method of steps S13131 to S13133 in the fifth embodiment.

[0132] refer to Figure 11 , Figure 11 This is a flowchart illustrating the seventh embodiment of the design method of the present invention.

[0133] Based on the first embodiment described above, the design method of this embodiment includes the following in step S30:

[0134] Step S31: Based on the location of each connecting hole 1, multiple evacuation staircases 400 leading to the evacuation passage 310 under the track are arranged at intervals along the tunnel length direction.

[0135] It should be noted that the spacing between two adjacent evacuation staircases 400 is the same as the spacing between two adjacent connecting holes 1.

[0136] Step S32: According to the shape and position of each connecting hole 1, the connecting holes 1 are opened on the side wall of each evacuation staircase 400 to connect the space above the track 200 with the evacuation passage below the track 310.

[0137] It should be noted that the two side walls of the evacuation staircase 400 are provided with the connecting holes 1, and the two connecting holes 1 are symmetrically arranged with the length direction of the tunnel as the axis of symmetry.

[0138] It should be noted that, in another embodiment, each of the connecting holes 1 is spaced apart at the top of the under-rail evacuation channel 310, so that the track space 200 is connected to the under-rail evacuation channel 310.

[0139] refer to Figure 12 , Figure 12 This is a flowchart illustrating the eighth embodiment of the design method of the present invention.

[0140] Based on the first embodiment described above, the design method of this embodiment further includes, after step S30:

[0141] Step S40: Install ventilation louver valves 2 that can be controlled by the controller at each of the aforementioned connecting holes 1, so that each ventilation louver valve 2 blocks the corresponding connecting hole 1.

[0142] It should be noted that, since the tunnel has a connecting hole 1 for connecting the track space 200 and the track space 300, in the event of a fire, dense smoke will spread from the connecting hole 1 to the track space 300. Therefore, each of the connecting holes 1 is sealed one by one by the multiple ventilation louver valves 2. Under normal operating conditions, the controller controls each of the ventilation louver valves 2 to open, and under fire conditions, the controller controls each of the ventilation louver valves 2 to close. This allows the connecting hole 1 to alleviate the aerodynamic effect of the train 500 under normal operating conditions, and also prevents dense smoke from spreading to the track space 300 through the connecting hole 1 under fire conditions.

[0143] It should be noted that the controller can control the opening degree of each of the ventilation louver valves 2, thereby adjusting the flow rate of gas in and out, and thus adjusting the mitigation effect on the aerodynamic effect of the train.

[0144] It should be understood that although the steps in the flowcharts of this application's embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0145] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0146] Furthermore, it should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0147] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for an aerodynamic effect mitigation system, characterized in that, Includes the following steps: The opening area of ​​each connecting hole and the spacing between two adjacent connecting holes along the tunnel length direction are determined based on various parameters of the train and the tunnel. The shape and position of each connecting hole are determined based on the opening area of ​​each connecting hole and the distance between two adjacent connecting holes. Based on the shape and location of each connecting hole, multiple connecting holes are arranged at intervals along the length of the tunnel to connect the track space and the track space.

2. The design method as described in claim 1, characterized in that, The determination of the opening area of ​​each connecting hole and the spacing between two adjacent connecting holes along the tunnel length direction based on various parameters of the train and the tunnel includes: Determine the standard clearance area on the track based on the train's design speed; Obtain the initial opening area and initial spacing of each connecting hole; The effective cross-sectional clearance area is obtained based on various parameters of the train and tunnel, the standard clearance area on the track, and the initial opening area and initial spacing of each connecting hole. The effective clearance area of ​​the cross section is compared with the standard clearance area on the track, and the opening area and spacing of each connecting hole are adjusted according to the comparison results until the difference between the standard clearance area on the track and the effective clearance area of ​​the cross section is less than a preset threshold. The current opening area and the current spacing are used as the opening area of ​​each connected hole and the spacing between two adjacent connected holes.

3. The design method as described in claim 2, characterized in that, The method of obtaining the effective cross-sectional clearance area based on various parameters of the train and tunnel, the standard clearance area on the track, and the initial opening area and initial spacing of each connecting hole includes: The first characteristic value is obtained based on the train model, train formation parameters, train design speed, train speed and time curve, train sealing performance parameters, tunnel length, and tunnel cross-sectional shape and tunnel cross-sectional layout parameters corresponding to the track clearance area. The second characteristic value is obtained based on the train model, train formation parameters, train design speed, train speed and time curve, train sealing performance parameters, tunnel length, actual tunnel cross-sectional shape, actual tunnel cross-sectional layout parameters, and the initial opening area and initial spacing of each connecting hole. The equivalent coefficient of the aerodynamic effect mitigation of the under-rail space and the under-rail clearance area is calculated based on the first characteristic value, the second characteristic value, the standard clearance area on the track, the actual clearance area on the track, and the actual area under the track. The effective net area of ​​the cross section is calculated based on the equivalent coefficient, the actual net area on the track, and the actual area under the track.

4. The design method as described in claim 3, characterized in that, The first characteristic value is obtained based on the train model, train formation parameters, train design speed, train speed-time curve, train sealing performance parameters, tunnel length, and tunnel cross-sectional shape and layout parameters corresponding to the track clearance area, including: The first three-dimensional model is established based on the train model, train formation parameters, train design speed, tunnel length, and the tunnel cross-sectional shape and layout parameters corresponding to the track clearance area. Based on the first three-dimensional model, the train speed and time curves, and the train sealing performance parameters, aerodynamic simulation tests were conducted under multiple working conditions, including a single vehicle passing through a tunnel and two vehicles meeting at different locations in the tunnel, to obtain the first transient pressure amplitude, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train in the tunnel. The first characteristic value is calculated based on the first transient pressure amplitude inside the tunnel, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train.

5. The design method as described in claim 4, characterized in that, The calculation of the first characteristic value based on the first transient pressure amplitude, the first micro-pressure wave amplitude, and the first internal and external pressure change rate of the train within the tunnel includes: The extreme value normalization method is used to normalize the amplitude of the first transient pressure, the amplitude of the first micro-pressure wave, and the rate of change of the first internal and external pressure of the train in the tunnel, so as to obtain the first normalization index, the second normalization index, and the third normalization index. The first weight value, the second weight value, and the third weight value are determined using the analytic hierarchy process (AHP), and the sum of the first weight value, the second weight value, and the third weight value is set to 1. The first normalized index, the second normalized index, and the third normalized index are weighted and calculated based on the first weight value, the second weight value, and the third weight value to obtain the first feature value.

6. The design method as described in claim 3, characterized in that, The second characteristic value is obtained based on the train model, train formation parameters, train design speed, train speed-time curve, train sealing performance parameters, tunnel length, actual tunnel cross-sectional shape, actual tunnel cross-sectional layout parameters, and the initial opening area and initial spacing of each connecting hole, including: A second three-dimensional model is established based on the train model, train formation parameters, train design speed, tunnel length, actual tunnel cross-sectional shape, and actual tunnel cross-sectional layout parameters. Based on the initial opening area and initial spacing of each connecting hole, multiple connecting holes are set in the tunnel model of the second three-dimensional model to obtain the updated second three-dimensional model. Based on the second three-dimensional model, the train speed and time curves, and the train sealing performance parameters, aerodynamic simulation tests were conducted under multiple working conditions, including a single vehicle passing through a tunnel and two vehicles meeting at different locations in the tunnel, to obtain the second transient pressure amplitude, the second micro-pressure wave amplitude, and the second internal and external pressure change rate of the train in the tunnel. The second characteristic value is calculated based on the second transient pressure amplitude inside the tunnel, the second micro-pressure wave amplitude, and the second internal and external pressure change rate of the train.

7. The design method as described in claim 1, characterized in that, The method of arranging multiple connecting holes at intervals along the tunnel length direction according to the shape and position of each connecting hole to connect the track space and the track space of the tunnel includes: Based on the location of each connecting hole, multiple evacuation staircases leading to the evacuation passage under the track are arranged at intervals along the length of the tunnel. The connecting holes are made on the side walls of each evacuation staircase according to their shape and location, so that the space above the track is connected to the evacuation passage below the track.

8. The design method as described in claim 1, characterized in that, After the step of arranging multiple connecting holes at intervals along the tunnel length direction according to the shape and position of each connecting hole to connect the track space and the track space of the tunnel, the method further includes: Ventilation louver valves, which can be controlled by a controller, are installed at each of the aforementioned connecting holes, so that each ventilation louver valve blocks the corresponding connecting hole.

9. A system for mitigating aerodynamic effects, characterized in that, It includes multiple connecting holes opened in the tunnel to connect the space above the track and the space below the track. The multiple connecting holes are arranged at intervals along the length of the tunnel. The shape and position of each connecting hole are determined by the design method described in any one of claims 1 to 8.

10. The aerodynamic effect mitigation system as described in claim 9, characterized in that, It also includes a controller and multiple ventilation louver valves, each ventilation louver valve being configured to correspond one-to-one with the multiple connecting holes to block each of the connecting holes. Each of the multiple ventilation louver valves is electrically connected to the controller, which is used to control the multiple ventilation louver valves to close in the event of a fire.

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