Method and system for train active resistance reduction

Abstract

To provide a method and a system for train active resistance reduction solving a technical problem of difficulty in reduction of energy consumption for travelling of a high speed train due to poor effect of a train aerodynamic resistance reduction method.SOLUTION: A method carries out active aerodynamic resistance reduction control for a train by: analyzing turbulence field variation due to different travelling vehicle speed of the train and an aerodynamic resistance result of the train by building a train light section aerodynamic resistance numerical calculation model; establishing an exhaust / suction control range on a head vehicle and / or rearmost vehicle of the train by analyzing a relation between train surface pressure, periphery air flow speed, and periphery air pressure based on the train aerodynamic resistance numerical result; establishing a relation between an aerodynamic resistance reduction rate and an exhaust / suction angle by analyzing an aerodynamic resistance reduction rate at different exhaust / suction speed at different travelling vehicle speed by providing one or a plurality of exhaust / suction holes in the exhaust / suction control range; and building a database for active exhaust / suction adjustment control parameter variation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technical field of train drag reduction, and more particularly to a method and system for active train drag reduction. [Background technology]

[0002] Energy consumption for high-speed trains is primarily due to overcoming aerodynamic resistance caused by inflow during travel. When a train travels at high speed, its aerodynamic resistance is directly proportional to the square of its running speed. When the train's speed exceeds 300 km / h, the aerodynamic resistance can reach 70% to 85% of its total resistance. Currently, train running resistance is reduced primarily by optimizing the external shape of the train's streamlined head and adjusting the train's local detailed structure, but the resistance reduction effect is limited. Increasing the length of the train's streamlined head is a more effective method. However, once the streamlined head reaches a certain length, its resistance reduction effect also has a certain limit, making it difficult to break through by continuously extending the length. Therefore, improving the aerodynamic resistance reduction effect of trains to save energy consumption during high-speed train travel is a technical problem that those skilled in the art are striving to solve. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention provides a method and system for active train drag reduction to solve the technical problem that the conventional methods for reducing train aerodynamic drag are ineffective and it is difficult to reduce energy consumption for high-speed train operation. [Means for solving the problem]

[0004] In view of this, a first aspect of the present invention provides a method for active train resistance reduction, the method comprising: constructing a train geometry model and a train open section aerodynamic resistance numerical calculation model; Calculating a train aerodynamic resistance numerical result based on the train geometry model and the train open section aerodynamic resistance numerical calculation model; Analyzing the relationship between the train surface pressure, the ambient air velocity, and the ambient air pressure based on the train aerodynamic resistance numerical results; determining an exhaust / intake control area on the streamlined head surface of the leading car and / or the trailing car of the train based on a relationship analysis result between the train surface pressure, the ambient air flow velocity, and the ambient air pressure according to the train geometry model, wherein the exhaust / intake control area is provided with one or more exhaust / intake holes; Obtaining aerodynamic drag reduction rates at different exhaust / intake speeds at different running vehicle speeds according to the train surface exhaust / intake control region, and determining the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; constructing an active exhaust / intake adjustment control parameter change database based on the aerodynamic drag reduction rate at different exhaust / intake speeds at different vehicle speeds and the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; and performing active aerodynamic drag reduction control on the train based on the active exhaust / intake adjustment control parameter change database.

[0005] Preferably, the relationships between the train surface pressure, the ambient air flow velocity, and the ambient air pressure are as shown in the following equations 1 to 3.

[0006]

number

[0007]

number

[0008]

number

[0009] C d is the resistance coefficient, and C lis the lift coefficient, and C p is the surface pressure coefficient, and F x is the resistance experienced by the train body, and F z is the lift force exerted on the train body, P is the train surface pressure, ρ is the air density, and U t is the train speed, P0 is the air pressure, and A is the reference area.

[0010] Preferably, the aerodynamic drag reduction rate is calculated using the following equation 4:

[0011]

number

[0012] ε d is the aerodynamic drag reduction rate, and C d-blow is the train resistance coefficient under exhaust conditions, and C d-ori is the train resistance coefficient under no exhaust conditions.

[0013] Preferably, the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is as shown in the following equations (5) and (6).

[0014]

number

[0015]

number

[0016] θ is the exhaust angle, h0 is the vertical distance from the exhaust port to the horizontal axis where the exhaust focus is located, and L is the distance from the exhaust focus to the train nose.

[0017] Preferably, the step of performing active aerodynamic drag reduction control on the train based on the active exhaust / intake adjustment control parameter change database includes: acquiring train speed data; Searching an active exhaust / intake adjustment control parameter change database based on train speed data to obtain an optimal exhaust / intake speed and an optimal exhaust / intake angle; and transmitting the optimum exhaust / intake speed and optimum exhaust / intake angle to a train fan control system, and controlling the rotation speed and rotation direction of the fan by the fan control system so as to reach the optimum exhaust / intake speed and optimum exhaust / intake angle, respectively, thereby performing active aerodynamic drag reduction control on the train.

[0018] A second aspect of the present invention provides a train active drag reduction system, the train active drag reduction system comprising: a modeling module for constructing a train geometry model and a train open section aerodynamic resistance numerical calculation model; an aerodynamic characteristic calculation module for calculating a train aerodynamic resistance numerical result based on a train geometric model and a train open section aerodynamic resistance numerical calculation model; an aerodynamic characteristic result analysis module that analyzes the relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure based on the train aerodynamic resistance numerical result; an intake / exhaust control area acquisition module for determining an exhaust / intake control area on the streamlined head surface of the leading car and / or the trailing car of the train based on a relationship analysis result between the train surface pressure, the ambient air flow velocity, and the ambient air pressure according to a train geometry model, wherein the exhaust / intake control area is provided with one or more exhaust / intake holes; an intake / exhaust speed and angle analysis module for obtaining the aerodynamic drag reduction rate at different exhaust / intake speeds at different running vehicle speeds based on the train surface exhaust / intake control region, and determining the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; an intake / exhaust adjustment control parameter database module for constructing an active exhaust / intake adjustment control parameter change database based on the aerodynamic drag reduction rate at different exhaust / intake speeds at different vehicle speeds and the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; and a drag reduction control module that performs active aerodynamic drag reduction control on the train based on the active exhaust / intake adjustment control parameter change database.

[0019] The relationships between the train surface pressure, the ambient air flow velocity, and the ambient air pressure are as shown in the following equations 7 to 9.

[0020]

number

[0021]

number

[0022]

number

[0023] C d is the resistance coefficient, and C l is the lift coefficient, and C p is the surface pressure coefficient, and F x is the resistance experienced by the train body, and F z is the lift force exerted on the train body, P is the train surface pressure, ρ is the air density, and U t is the train speed, P0 is the air pressure, and A is the reference area.

[0024] Preferably, the aerodynamic drag reduction rate is calculated using the following equation:

[0025]

number

[0026] ε d is the aerodynamic drag reduction rate, and C d-blow is the train resistance coefficient under exhaust conditions, and C d-ori is the train resistance coefficient under no exhaust conditions.

[0027] Preferably, the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is as shown in the following equations 11 and 12.

[0028]

number

[0029]

number

[0030] θ is the exhaust angle, h0 is the vertical distance from the exhaust port to the horizontal axis where the exhaust focus is located, and L is the distance from the exhaust focus to the train nose.

[0031] Preferably, the drag reduction control module specifically: Acquire train speed data, Based on the train speed data, search the active exhaust / intake adjustment control parameter change database to obtain the optimal exhaust / intake speed and optimal exhaust / intake angle; The optimum exhaust / intake speed and optimum exhaust / intake angle are transmitted to the train fan control system, which controls the fan rotation speed and rotation direction to reach the optimum exhaust / intake speed and optimum exhaust / intake angle, thereby performing active aerodynamic drag reduction control for the train. [Effects of the Invention]

[0032] As can be seen from the above technical solutions, the active train resistance reduction method provided by the present invention has the following advantages: In the active train drag reduction method provided by the present invention, a numerical calculation model for the aerodynamic resistance of a train's open section is constructed, and the turbulence field fluctuations and the aerodynamic resistance results of the train at different running speeds are analyzed. Based on the numerical results of the aerodynamic resistance of the train, the relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure is analyzed. This is used to determine the exhaust / intake control area on the streamlined head surface of the lead car and / or the tail car of the train. One or more exhaust / intake holes are provided in the exhaust / intake control area. The aerodynamic drag reduction rate at different exhaust / intake velocities at different running speeds is analyzed, the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is determined, and an active exhaust / intake adjustment control parameter change database is constructed to perform active aerodynamic drag reduction control on the train, thereby avoiding the problem of the limited drag reduction effect of drag reduction methods that increase the length of the streamlined head of the train. This solves the technical problem of the poor effectiveness of conventional methods for reducing aerodynamic drag of trains and the difficulty of reducing energy consumption for high-speed trains.

[0033] In order to more clearly explain the technical solutions of the embodiments of the present invention or the prior art, the following briefly introduces the drawings necessary for the description of the embodiments or the prior art. The drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other related drawings based on these drawings without exerting any effort that amounts to inventive step. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a flow diagram of a method for active train drag reduction according to an embodiment of the present invention; [Figure 2] 1 is an exemplary side view of a train surface exhaust / intake control area according to an embodiment of the present invention; [Figure 3] 1 is an exemplary perspective view of a train surface exhaust / intake control area according to an embodiment of the present invention; [Figure 4] 1 is a graph showing a change curve of the aerodynamic resistance of each car of a train according to an embodiment of the present invention as it changes with the exhaust speed, where Ub is the exhaust speed, Ut is the vehicle speed, and Ub / Ut is the dimensionless exhaust speed. [Figure 5]A graph showing the change in aerodynamic resistance of the entire train according to an embodiment of the present invention as a function of exhaust velocity. [Figure 6] 1 is a graph showing the change in aerodynamic lift of each car of a train according to an embodiment of the present invention as the exhaust velocity changes. [Figure 7] 10A and 10B are diagrams showing the swirl changes around the streamlined head surface of a train according to an embodiment of the present invention when exhausting at different exhaust velocities. [Figure 8] Schematic diagram showing how the exhaust angle is changed by changing the focal position according to an embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing the drag reduction effect of each car of a train at different exhaust angles according to an embodiment of the present invention. [Figure 10] FIG. 10 shows the drag reduction effect of different exhaust angles on different resistances of a train according to an embodiment of the present invention. [Figure 11] 1 is a structural schematic diagram of a train active drag reduction system according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0035] In order to enable those skilled in the art to better understand the solution of the present invention, the following clearly and completely describes the technical solutions of the embodiments of the present invention, combined with the drawings of the embodiments of the present invention, and the described embodiments are not all embodiments, but only some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any inventive efforts are within the protection scope of the present invention.

[0036] For ease of understanding, referring to FIG. 1, the present invention provides an embodiment of a train active drag reduction method, which includes the following steps: In step 101, a train geometry model and a train open section aerodynamic resistance numerical calculation model are constructed.

[0037] Here, a 3D computer-aided modeling software such as CAD is used to construct a geometric model of a high-speed train's multi-car formation, and then a structural model of supporting facilities such as the railway and roadbed is constructed. Based on the constructed high-speed train geometric model and the structural model of supporting facilities such as the railway and roadbed, a numerical calculation model of the aerodynamic resistance of high-speed train open sections is constructed using CFD preprocessing software, and the calculation domain and appropriate boundary conditions are simulated, and grid division is performed for the calculation domain.

[0038] In step 102, the train aerodynamic resistance numerical result is calculated based on the train geometry model and the train open section aerodynamic resistance numerical calculation model.

[0039] Here, based on the constructed train geometric model and train open section aerodynamic resistance numerical calculation model, the train open section aerodynamic resistance is calculated to obtain the train aerodynamic resistance numerical result.

[0040] In step 103, the relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure is analyzed based on the train aerodynamic resistance numerical results.

[0041] Here, the relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure is analyzed based on the calculation result of step 102. The relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure is expressed by the following equations 13 to 15.

[0042]

number

[0043]

number

[0044]

number

[0045] C dis the resistance coefficient, and C l is the lift coefficient, and C p is the surface pressure coefficient, and F x is the resistance experienced by the train body, and F z is the lift force exerted on the train body, P is the train surface pressure, ρ is the air density, and is 1.225 kg / m 3 is set to U t is the train speed, P0 is the air pressure, A is the reference area, and 11.22m 2 is set to

[0046] Based on the air velocity streamline distribution and vortex structure near the train, we clarify the special flow characteristics that form a strong correlation with the aerodynamic resistance of trains, such as the flow field structure fluctuations near the train, vortex development and evolution process, and air flow separation and reattachment, and further disclose the generation mechanism and evolution discipline of vortex flow around the car body.

[0047] In step 104, according to the train geometry model, based on the relationship analysis results between the train surface pressure, the ambient air flow velocity, and the ambient air pressure, an exhaust / intake control area on the streamlined head surface of the leading car and / or the trailing car of the train is determined, and one or more exhaust / intake holes are provided in the exhaust / intake control area.

[0048] Here, surface exhaust / intake control areas are arranged in the streamlined head regions of the leading and trailing cars of a train based on a high-speed train geometric model constructed using computer-aided 3D modeling software such as CAD, examples of which include, but are not limited to, those shown in Figures 2 and 3. Exhaust / intake holes may be provided simultaneously in the streamlined head regions of the leading and trailing cars of a high-speed train formation, or only in the streamlined head regions of the leading or trailing cars of a high-speed train formation, see, for example, AB-1, AB-2, and AB-3 in Figure 3. The arrangement of air holes in the surface exhaust / intake control areas may be equally spaced and with equal opening widths, or may be unevenly spaced and with uneven opening widths, and may be designed based on constraints such as the specific size, molding line direction, chamfer size, and strength requirements of the vehicle type, but should not affect the streamlined outline and running safety of the entire train.

[0049] In step 105, based on the train surface exhaust / intake control region, the aerodynamic drag reduction rate at different exhaust / intake speeds at different running vehicle speeds is obtained, and the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is determined.

[0050] Here, based on the determined train surface exhaust / intake control region, the aerodynamic drag reduction rate at different exhaust / intake speeds at different running vehicle speeds is calculated, and the calculation formula for the aerodynamic drag reduction rate is as follows:

[0051]

number

[0052] ε d is the aerodynamic drag reduction rate, and C d-blow is the train resistance coefficient under exhaust conditions, and C d-ori is the train resistance coefficient under no exhaust conditions.

[0053] Correspondingly, the aerodynamic lift reduction rate at different exhaust / intake velocities at different vehicle speeds may be calculated, and the calculation formula is as follows:

[0054]

number

[0055] ε l is the aerodynamic lift reduction rate, and C l-blow is the train lift coefficient under exhaust conditions, and C l-Ori is the train lift coefficient under no exhaust conditions.

[0056] Figures 4 to 6 show the curves of the aerodynamic resistance / aerodynamic lift of a train as it changes with exhaust speed when a train of a certain train model number is traveling at a certain speed, with exhaust holes simultaneously installed on the streamlined head surfaces of the leading and trailing cars of the train.

[0057] We build a numerical simulation model or conduct wind tunnel tests to study the effect of different exhaust / intake angles on the aerodynamic drag reduction rate of a train. The exhaust / intake angle θ is the angle between the vertical direction and the exhaust direction. The tangent value of the exhaust / intake angle θ is the ratio of the vertical distance h0 from the exhaust port to the horizontal axis where the exhaust focus is located to the distance L from the exhaust focus to the nose of the train.

[0058]

number

[0059] As shown in Figure 8, the exhaust / intake angle is changed by changing the position from focal point F (F1-F4) to the train nose. The changes in the train surface pressure distribution and wake structure are observed, and the aerodynamic parameters of the train at different exhaust / intake angles are recorded, including the friction drag coefficient, pressure difference drag coefficient, and surface pressure coefficient. Experimental results are analyzed to establish a mathematical model or relationship between the exhaust / intake angle and the drag reduction rate. The influence of the exhaust / intake angle on the drag reduction rate is determined statistically. As can be seen, the wake vortex structure is significantly improved. After determining the relationship between the exhaust / intake angle and the drag reduction rate, the exhaust / intake angle is adjusted to control the train's resistance. For specific running conditions, the optimal exhaust / intake angle is selected based on the mathematical model or experimental results of the exhaust / intake angle-drag reduction rate relationship to achieve the drag reduction goal. The exhaust / intake angle is adjusted using an electrohydraulic system to control adjustable components in the exhaust / intake system, such as the exhaust / intake port directional control device. As can be seen from the results of the numerical simulation, the drag reduction performance improves as the distance between the exhaust focus and the train nose decreases and the wake flow direction approaches the train surface.

[0060] Aerodynamic drag reduction rate ε was calculated by numerical simulation. d and the focal length L, the relationship between

[0061]

number

[0062] In step 106, an active exhaust / intake adjustment control parameter change database is constructed based on the aerodynamic drag reduction rate at different exhaust / intake speeds at different vehicle speeds and the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle.

[0063] Based on the relationship between aerodynamic drag reduction rate and exhaust / intake angle, we analyzed the effects of different running vehicle speeds (inflow wind speeds), different exhaust / intake velocities, and different exhaust / intake angles on the surface pressure and ambient air flow velocity of a high-speed train. Based on the air velocity streamline distribution and vortex structure near the train, we analyzed the effects of different exhaust velocities, different exhaust shapes, and different exhaust angles on the flow field structure near the train, as well as the development and evolution of vortices. We then determined the optimal exhaust / intake velocities and exhaust / intake angles for different running vehicle speeds. Figure 7 shows the change in vortexes near a certain model train when it is running at a specific speed, with exhaust ports installed on the streamlined head surfaces of both the front and rear cars of the train.

[0064] Based on the above analysis results, the correspondence between the aerodynamic drag reduction rate of high-speed trains and the optimal exhaust / intake speed and optimal exhaust / intake angle at different running speeds and different exhaust velocities is obtained, and a database of changes in train active exhaust / intake adjustment control parameters is constructed.

[0065] In step 107, active aerodynamic drag reduction control is performed on the train based on the active exhaust / intake adjustment control parameter change database.

[0066] The active exhaust / intake adjustment control parameter change database contains a correspondence between aerodynamic drag reduction rates and optimal exhaust / intake speeds and optimal exhaust / intake angles. Therefore, active aerodynamic drag reduction control is performed on the train based on the active exhaust / intake adjustment control parameter change database. Specifically, train speed data is first acquired, and the active exhaust / intake adjustment control parameter change database is searched based on the train speed data to obtain optimal exhaust / intake speeds and optimal exhaust / intake angles. The optimal exhaust / intake speeds and optimal exhaust / intake angles are then transmitted to the train fan control system. The fan control system then controls the fan rotation speed and rotation direction to achieve the optimal exhaust / intake speeds and optimal exhaust / intake angles, thereby performing active aerodynamic drag reduction control on the train. For the drag reduction effect, please refer to Figures 9 and 10.

[0067] In the active train drag reduction method provided by the present invention, a numerical calculation model for the aerodynamic resistance of a train's open section is constructed, and the turbulence field fluctuations and the aerodynamic resistance results of the train at different running speeds are analyzed. Based on the numerical results of the aerodynamic resistance of the train, the relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure is analyzed. This is used to determine the exhaust / intake control area on the streamlined head surface of the lead car and / or the tail car of the train. One or more exhaust / intake holes are provided in the exhaust / intake control area. The aerodynamic drag reduction rate at different exhaust / intake velocities at different running speeds is analyzed, the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is determined, and an active exhaust / intake adjustment control parameter change database is constructed to perform active aerodynamic drag reduction control on the train, thereby avoiding the problem of the limited drag reduction effect of the drag reduction method of increasing the length of the streamlined head of the train. This solves the technical problem of the poor effectiveness of conventional methods for reducing aerodynamic resistance of trains and the difficulty of reducing energy consumption for high-speed trains.

[0068] For ease of understanding, referring to FIG. 11, the present invention provides an embodiment of a train active drag reduction system, which includes: a modeling module for constructing a train geometry model and a train open section aerodynamic resistance numerical calculation model; an aerodynamic characteristic calculation module for calculating a train aerodynamic resistance numerical result based on a train geometric model and a train open section aerodynamic resistance numerical calculation model; an aerodynamic characteristic result analysis module that analyzes the relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure based on the train aerodynamic resistance numerical result; an intake / exhaust control area acquisition module for determining an exhaust / intake control area on the streamlined head surface of the leading car and / or the trailing car of the train based on a relationship analysis result between the train surface pressure, the ambient air flow velocity, and the ambient air pressure according to a train geometry model, wherein the exhaust / intake control area is provided with one or more exhaust / intake holes; an intake / exhaust speed and angle analysis module for obtaining the aerodynamic drag reduction rate at different exhaust / intake speeds at different running vehicle speeds based on the train surface exhaust / intake control region, and determining the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; an intake / exhaust adjustment control parameter database module for constructing an active exhaust / intake adjustment control parameter change database based on the aerodynamic drag reduction rate at different exhaust / intake speeds at different vehicle speeds and the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; and a drag reduction control module that performs active aerodynamic drag reduction control on the train based on the active exhaust / intake adjustment control parameter change database.

[0069] The relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure is expressed by the following equations (20) to (22).

[0070]

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[0071]

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[0072]

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[0073] C d is the resistance coefficient, and C l is the lift coefficient, and C p is the surface pressure coefficient, and F x is the resistance experienced by the train body, and F z is the lift force exerted on the train body, P is the train surface pressure, ρ is the air density, and U t is the train speed, P0 is the air pressure, and A is the reference area.

[0074] The formula for calculating the aerodynamic drag reduction rate is as follows:

[0075]

number

[0076] ε d is the aerodynamic drag reduction rate, and C d-blow is the train resistance coefficient under exhaust conditions, and C d-ori is the train resistance coefficient under no exhaust conditions.

[0077] The relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is given by the following equations (24) and (25).

[0078]

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[0079]

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[0080] θ is the exhaust angle, h0 is the vertical distance from the exhaust port to the horizontal axis where the exhaust focus is located, and L is the distance from the exhaust focus to the train nose.

[0081] Specifically, the drag reduction control module: Acquire train speed data, Based on the train speed data, search the active exhaust / intake adjustment control parameter change database to obtain the optimal exhaust / intake speed and optimal exhaust / intake angle; The optimum exhaust / intake speed and optimum exhaust / intake angle are transmitted to the train fan control system, which controls the fan rotation speed and rotation direction to reach the optimum exhaust / intake speed and optimum exhaust / intake angle, thereby performing active aerodynamic drag reduction control for the train.

[0082] The active train resistance reduction system provided by the present invention implements the active train resistance reduction method provided by the present invention, and its principles and obtained technical effects are the same as those of the active train resistance reduction method provided by the present invention, and no further description is given here.

[0083] As mentioned above, the above embodiments do not limit the technical solutions of the present invention, but are merely used for illustration. The present invention has been described in detail with reference to the above embodiments. However, as can be understood by those skilled in the art, the technical solutions described in the above embodiments may still be amended or some of the technical features may be equivalently replaced, and the essence of the corresponding technical solutions will not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention due to such amendments or replacements.

Claims

1. A method for active train resistance reduction, comprising: constructing a train geometry model and a train open section aerodynamic resistance numerical calculation model; Calculating a train aerodynamic resistance numerical result based on the train geometry model and the train open section aerodynamic resistance numerical calculation model; Analyzing the relationship between the train surface pressure, the ambient air velocity, and the ambient air pressure based on the train aerodynamic resistance numerical results; determining an exhaust / intake control area on the streamlined head surface of the leading car and / or the trailing car of the train based on a relationship analysis result between the train surface pressure, the ambient air flow velocity, and the ambient air pressure according to the train geometry model, wherein the exhaust / intake control area is provided with one or more exhaust / intake holes; Obtaining aerodynamic drag reduction rates at different exhaust / intake speeds at different running vehicle speeds according to the train surface exhaust / intake control region, and determining the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; constructing an active exhaust / intake adjustment control parameter change database based on the aerodynamic drag reduction rate at different exhaust / intake speeds at different vehicle speeds and the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; and performing active aerodynamic drag reduction control on the train based on the active exhaust / intake adjustment control parameter change database.

2. The relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure is as shown in the following equations 1 to 3: [Equation 1] [Equation 2] [Equation 3] C ｄ is the resistance coefficient, and C ｌ is the lift coefficient, and C ｐ is the surface pressure coefficient, F ｘ is the resistance received by the train body, and F ｚ is the lift force applied to the train body, P is the train surface pressure, ρ is the air density, and U ｔ is the train speed, and P ０ 2. The method for reducing train resistance according to claim 1, wherein: ρ is the air pressure; and A is the reference area.

3. The calculation formula for the aerodynamic drag reduction rate is as follows: [Equation 4] ε ｄ is the aerodynamic drag reduction rate, and C ｄ－ｂｌｏｗ is the train resistance coefficient under exhaust conditions, and C ｄ－ｏｒｉ 3. The method for reducing train resistance according to claim 2, wherein: is the train resistance coefficient under no exhaust conditions.

4. The relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is as shown in the following equations 5 and 6: [Equation 5] [Equation 6] θ is the exhaust angle, and h ０ 4. The method for reducing the active drag of a train according to claim 3, wherein λ is the vertical distance from the exhaust port to the horizontal axis on which the exhaust focus is located, and L is the distance from the exhaust focus to the nose of the train.

5. The step of performing active aerodynamic drag reduction control on the train based on the active exhaust / intake adjustment control parameter change database includes: acquiring train speed data; Searching an active exhaust / intake adjustment control parameter change database based on train speed data to obtain an optimal exhaust / intake speed and an optimal exhaust / intake angle; and transmitting the optimum exhaust / intake speed and optimum exhaust / intake angle to a train fan control system, and controlling the rotation speed and rotation direction of the fan by the fan control system so as to reach the optimum exhaust / intake speed and optimum exhaust / intake angle, thereby performing active aerodynamic drag reduction control on the train.

6. A train active drag reduction system, comprising: a modeling module for constructing a train geometry model and a train open section aerodynamic resistance numerical calculation model; an aerodynamic characteristic calculation module for calculating a train aerodynamic resistance numerical result based on a train geometric model and a train open section aerodynamic resistance numerical calculation model; an aerodynamic characteristic result analysis module that analyzes the relationship between the train surface pressure, the ambient air flow velocity, and the ambient air pressure based on the train aerodynamic resistance numerical result; an intake / exhaust control area acquisition module for determining an exhaust / intake control area on a streamlined head surface of the leading car and / or the trailing car of the train based on a relationship analysis result between the train surface pressure, the ambient air flow velocity, and the ambient air pressure in accordance with a train geometry model, wherein the exhaust / intake control area is provided with one or more exhaust / intake holes; an intake / exhaust speed and angle analysis module for obtaining aerodynamic drag reduction rates at different exhaust / intake speeds at different running vehicle speeds according to the train surface exhaust / intake control region, and determining the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; an intake / exhaust adjustment control parameter database module for constructing an active exhaust / intake adjustment control parameter change database based on the aerodynamic drag reduction rate at different exhaust / intake speeds at different vehicle speeds and the relationship between the aerodynamic drag reduction rate and the exhaust / intake angle; and a drag reduction control module that performs active aerodynamic drag reduction control on the train based on an active exhaust / intake adjustment control parameter change database.

7. The relationships between the train surface pressure, the ambient air flow velocity, and the ambient air pressure are as shown in the following equations 7 to 9: [Equation 7] [Equation 8] [Equation 9] C ｄ is the resistance coefficient, and C ｌ is the lift coefficient, and C ｐ is the surface pressure coefficient, F ｘ is the resistance received by the train body, and F ｚ is the lift force applied to the train body, P is the train surface pressure, ρ is the air density, and U ｔ is the train speed, and P ０ 7. The train active drag reduction system according to claim 6, wherein: ρ is the air pressure; and A is the reference area.

8. The calculation formula for the aerodynamic drag reduction rate is as follows: [Equation 10] ε ｄ is the aerodynamic drag reduction rate, and C ｄ－ｂｌｏｗ is the train resistance coefficient under exhaust conditions, and C ｄ－ｏｒｉ 8. The train active drag reduction system according to claim 7, wherein: is the train drag coefficient under no exhaust conditions.

9. The relationship between the aerodynamic drag reduction rate and the exhaust / intake angle is as shown in the following equations 11 and 12: [0011] [0012] θ is the exhaust angle, and h ０ 9. The train active drag reduction system of claim 8, wherein Λ is the vertical distance from the exhaust port to the horizontal axis on which the exhaust focus is located, and L is the distance from the exhaust focus to the train nose.

10. The drag reduction control module is Acquire train speed data, Searching an active exhaust / intake adjustment control parameter change database based on train speed data to obtain an optimal exhaust / intake speed and an optimal exhaust / intake angle; 7. The train active drag reduction system according to claim 6, wherein the optimum exhaust / intake speed and optimum exhaust / intake angle are transmitted to a train fan control system, and the fan control system controls the rotation speed and rotation direction of the fan so as to reach the optimum exhaust / intake speed and optimum exhaust / intake angle, thereby performing active aerodynamic drag reduction control for the train.

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