Train active drag reduction method and system

Abstract

The invention discloses an active resistance reduction method and system for a train, and the method comprises the steps: building a train open line aerodynamic resistance numerical calculation model, and analyzing the sudden change of a turbulent flow field caused by different running speeds of the train and the aerodynamic resistance result of the train; the method comprises the following steps: analyzing the relationship between train surface pressure and ambient air velocity and the relationship between the train surface pressure and ambient air pressure on the basis of a train aerodynamic resistance numerical result, determining an air blowing / suction control area on the streamline head surface of a head train and / or a tail train of the train, and forming one or more air blowing / suction holes in the air blowing / suction control area, and analyzing the pneumatic drag reduction rates at different air blowing / suction speeds at different running speeds, determining the relationship between the pneumatic drag reduction rates and the air blowing / suction angles, constructing an active air blowing / suction regulation and control parameter change database, and performing active pneumatic drag reduction control on the train. The technical problems that an existing train pneumatic drag reduction method is poor in effect, and energy consumption of high-speed train operation is difficult to reduce are solved.

Description

Technical Field

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

[0002] The energy consumption of high-speed train operation is mainly used to overcome the aerodynamic resistance caused by the oncoming flow during operation. When the train runs at high speed, its aerodynamic resistance is proportional to the square of its running speed. When the running speed of the train is higher than 300km / h, the aerodynamic resistance it encounters can reach 70%-85% of its total resistance. At present, the running resistance of the train is mainly reduced by optimizing the streamlined head shape of the train and adjusting the local detailed structure of the train, but the drag reduction effect is limited. In contrast, increasing the length of the streamlined head of the train is one of the more effective methods. However, when the streamlined head of the train reaches a certain length, its drag reduction effect will also show certain limitations, and it is difficult to achieve a breakthrough by extending its length. Therefore, how to improve the aerodynamic drag reduction effect of the train to save the energy consumption of high-speed train operation is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0003] The present invention provides a train active drag reduction method and system, which are used to solve the technical problem that the existing train aerodynamic drag reduction method has poor effect and is difficult to reduce the energy consumption of high-speed train operation.

[0004] In view of this, a first aspect of the present invention provides a method for active train drag reduction, comprising:

[0005] Construct train geometry model and numerical calculation model of train open line aerodynamic drag;

[0006] Calculate the numerical results of the train's aerodynamic drag based on the train's geometric model and the train's open-line aerodynamic drag numerical calculation model;

[0007] Based on the numerical results of train aerodynamic drag, the relationship between train surface pressure and surrounding air velocity and surrounding air pressure is analyzed;

[0008] According to the train geometric model, based on the analysis result of the relationship between the train surface pressure and the surrounding air flow velocity and the surrounding air pressure, determine the blowing / suction control area of ​​the streamlined head surface of the train head car and / or the tail car, and set one or more blowing / suction holes in the blowing / suction control area;

[0009] Based on the blowing / inhaling control area on the train surface, the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds is obtained, and the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle is determined;

[0010] Based on the aerodynamic drag reduction rate at different blowing / inhalation speeds at different running speeds and the relationship between the aerodynamic drag reduction rate and the blowing / inhalation angle, a database of active blowing / inhalation control parameter changes is constructed;

[0011] Based on the database of active blowing / inhalation control parameter changes, active aerodynamic drag reduction control is performed on the train.

[0012] Optionally, the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure is:

[0013]

[0014]

[0015]

[0016] Among them, C d is the drag coefficient, C l is the lift coefficient, C p is the surface pressure coefficient, F x is the resistance of the train body, F z is the lift force on the train body, P is the surface pressure of the train, ρ is the air density, U t is the train speed, P0 is the air pressure, and A is the reference area.

[0017] Optionally, the calculation formula of the aerodynamic drag reduction rate is:

[0018]

[0019] Among them, ε d is the aerodynamic drag reduction rate, C d-blow is the train resistance coefficient under blowing conditions, C d-ori is the train resistance coefficient without air blowing.

[0020] Optionally, the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle is:

[0021]

[0022] ε d =0.04L 2 -1.32L+15.88

[0023] Among them, θ is the blowing angle, h0 is the vertical distance between the blowing hole and the horizontal axis where the blowing focus is located, and L is the distance between the blowing focus and the nose tip of the train.

[0024] Optionally, based on the active blowing / inhalation control parameter change database, active aerodynamic drag reduction control is performed on the train, including:

[0025] Get train speed data;

[0026] According to the train speed data, query the active blowing / inhalation control parameter change database to obtain the optimal blowing / inhalation speed and the optimal blowing / inhalation angle;

[0027] The optimal blowing / inhalation speed and the optimal blowing / inhalation angle are transmitted to the train fan control system, and the fan control system controls the fan speed and direction to achieve the optimal blowing / inhalation speed and the optimal blowing / inhalation angle respectively, thereby performing active aerodynamic drag reduction control on the train.

[0028] A second aspect of the present invention provides a train active drag reduction system, comprising:

[0029] Modeling module, used to construct train geometry model and numerical calculation model of train open line aerodynamic resistance;

[0030] An aerodynamic characteristic calculation module is used to calculate the numerical result of the train aerodynamic resistance based on the train geometry model and the train open line aerodynamic resistance numerical calculation model;

[0031] The aerodynamic characteristics result analysis module is used to analyze the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure based on the numerical results of the train aerodynamic resistance;

[0032] A blowing / suction control area acquisition module is used to determine the blowing / suction control area of ​​the streamlined head surface of the leading car and / or the trailing car of the train according to the train geometric model and the relationship analysis result between the train surface pressure and the surrounding air flow velocity and the surrounding air pressure, and to set one or more blowing / suction holes in the blowing / suction control area;

[0033] The blowing / inhaling speed angle analysis module is used to obtain the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds based on the blowing / inhaling control area on the train surface, and determine the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle;

[0034] The blowing / inhalation control parameter database module is used to construct an active blowing / inhalation control parameter change database based on the aerodynamic drag reduction rate at different blowing / inhalation speeds at different running vehicle speeds and the relationship between the aerodynamic drag reduction rate and the blowing / inhalation angle;

[0035] The drag reduction control module is used to perform active aerodynamic drag reduction control on the train based on the active blowing / inhalation control parameter change database.

[0036] The relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure is:

[0037]

[0038]

[0039]

[0040] Among them, C d is the drag coefficient, C l is the lift coefficient, C p is the surface pressure coefficient, F x is the resistance of the train body, F z is the lift force on the train body, P is the surface pressure of the train, ρ is the air density, U t is the train speed, P0 is the air pressure, and A is the reference area.

[0041] Optionally, the calculation formula of the aerodynamic drag reduction rate is:

[0042]

[0043] Among them, ε d is the aerodynamic drag reduction rate, C d-blow is the train resistance coefficient under blowing conditions, C d-ori is the train resistance coefficient without air blowing.

[0044] Optionally, the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle is:

[0045]

[0046] ε d =0.04L 2 -1.32L+15.88

[0047] Among them, θ is the blowing angle, h0 is the vertical distance between the blowing hole and the horizontal axis where the blowing focus is located, and L is the distance between the blowing focus and the nose tip of the train.

[0048] Optionally, the drag reduction control module is specifically used for:

[0049] Get train speed data;

[0050] According to the train speed data, query the active blowing / inhalation control parameter change database to obtain the optimal blowing / inhalation speed and the optimal blowing / inhalation angle;

[0051] The optimal blowing / inhalation speed and the optimal blowing / inhalation angle are transmitted to the train fan control system, and the fan control system controls the fan speed and direction to achieve the optimal blowing / inhalation speed and the optimal blowing / inhalation angle respectively, thereby performing active aerodynamic drag reduction control on the train.

[0052] It can be seen from the above technical solutions that the train active drag reduction method provided by the present invention has the following advantages:

[0053] The active train drag reduction method provided by the present invention establishes a numerical calculation model of the train's open-line aerodynamic drag, analyzes the sudden changes in turbulent flow fields caused by the train at different running speeds and the aerodynamic drag results of the train, analyzes the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure based on the numerical results of the train's aerodynamic drag, determines the blowing / inhaling control area on the streamlined head surface of the train's head car and / or tail car, sets one or more blowing / inhaling holes in the blowing / inhaling control area, analyzes the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds, determines the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle, constructs an active blowing / inhaling control parameter change database, performs active aerodynamic drag reduction control on the train, avoids the problem that the drag reduction effect of the drag reduction method by increasing the length of the streamlined head of the train is limited, and solves the technical problem that the existing train aerodynamic drag reduction method is not effective and it is difficult to reduce the energy consumption of high-speed train operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1 A schematic diagram of a flow chart of a train active drag reduction method provided in an embodiment of the present invention;

[0056] Figure 2 A side view of an example of a train surface blowing / suction control area provided in an embodiment of the present invention

[0057] Figure 3 An axonometric diagram of an example of a train surface blowing / suction control area provided in an embodiment of the present invention;

[0058] Figure 4 : is a curve showing the change of aerodynamic resistance of each train segment with the change of blowing speed provided in the embodiment of the present invention, U b is the blowing speed, U t is the vehicle speed, U b / U t is the dimensionless blowing velocity;

[0059] Figure 5 The curve showing the change of the aerodynamic resistance of the whole train with the change of the blowing speed provided in the embodiment of the present invention;

[0060] Figure 6 The curve of the aerodynamic lift of each segment of the train as the blowing speed changes is provided in the embodiment of the present invention;

[0061] Figure 7 The streamlined head surface of the train provided in the embodiment of the present invention is blown at different blowing speeds to change the vortex near it;

[0062] Figure 8 A schematic diagram of changing the focal position to change the blowing angle provided in an embodiment of the present invention;

[0063] Fig. 9 The drag reduction effect of each train segment at different blowing angles provided in the embodiment of the present invention;

[0064] Fig.10 The drag reduction effect of different train resistances at different blowing angles provided in the embodiment of the present invention;

[0065] Fig.11 It is a schematic structural diagram of a train active drag reduction system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] For easier understanding, see Figure 1 The present invention provides an embodiment of a train active drag reduction method, comprising:

[0068] Step 101: construct a train geometry model and a numerical calculation model of the train's open-wire aerodynamic drag.

[0069] It should be noted that the geometric model of high-speed train multi-car formation can be established by using computer 3D modeling software such as CAD, and the structural model of auxiliary facilities such as tracks and roadbeds can also be constructed. Based on the established high-speed train geometric model and the structural model of auxiliary facilities such as tracks and roadbeds, the CFD pre-processing software is used to establish the simulation calculation area and suitable boundary conditions of the high-speed train open line aerodynamic drag numerical calculation model and mesh the calculation area.

[0070] Step 102: Calculate the numerical result of the train aerodynamic drag based on the train geometry model and the train open line aerodynamic drag numerical calculation model.

[0071] It should be noted that, based on the established train geometry model and the numerical calculation model of the train's open-wire aerodynamic drag, the train's open-wire aerodynamic drag is calculated to obtain the numerical result of the train's aerodynamic drag.

[0072] Step 103: Analyze the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure based on the numerical results of the train aerodynamic resistance.

[0073] It should be noted that, based on the calculation result of step 102, the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure is analyzed. The relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure is:

[0074]

[0075]

[0076]

[0077] Among them, C d is the drag coefficient, C l is the lift coefficient, C p is the surface pressure coefficient, F x is the resistance of the train body, F z is the lift force on the train body, P is the surface pressure of the train, and ρ is the air density, which is 1.225 kg / m 3 , U t is the train speed, P0 is the air pressure, A is the reference area, which is 11.22m 2 .

[0078] Based on the air velocity streamline distribution and turbulent vortex structure near the train, the special flow characteristics that are strongly correlated with the aerodynamic drag of the train, such as the flow field structure mutation, turbulent vortex development and evolution process, and airflow separation and reattachment near the train, are clarified, which can further reveal the generation mechanism and development law of the stream vortex around the car body.

[0079] Step 104: According to the train geometry model and based on the analysis results of the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure, determine the blowing / suction control area of ​​the streamlined head surface of the leading car and / or the trailing car of the train, and set one or more blowing / suction holes in the blowing / suction control area.

[0080] It should be noted that, using CAD and other computer-aided three-dimensional modeling software, based on the established high-speed train geometric model, surface blowing / suction control areas are set in the streamlined head area of ​​the train head car and the tail car, including but not limited to Figure 2 and Figure 3 The blow / suction holes can be set at the streamlined front of both the leading and trailing cars of a high-speed train, or only at the streamlined front of the leading or trailing car of a high-speed train. Figure 3AB-1, AB-2, AB-3 in the figure; the arrangement of air holes in the surface blowing / suction control area can be of equal spacing and equal opening width, or of unequal spacing and unequal opening width. The specific design can be based on the specific dimensions of the vehicle model, the direction of the main profile, the size of the chamfer, the strength requirements and other restrictive conditions, but it should not affect the overall streamline shape and operation safety of the train.

[0081] Step 105: Based on the blowing / inhaling control area on the train surface, obtain the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds, and determine the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle.

[0082] It should be noted that, based on the determined blowing / inhaling control area on the train surface, the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds is calculated. The calculation formula of the aerodynamic drag reduction rate is:

[0083]

[0084] Among them, ε d is the aerodynamic drag reduction rate, C d-blow is the train resistance coefficient under blowing conditions, C d-ori is the train resistance coefficient without air blowing.

[0085] Accordingly, the reduction rate of aerodynamic lift at different blowing / inhaling speeds at different running speeds can also be calculated, and the calculation formula is:

[0086]

[0087] Among them, ε l is the aerodynamic lift reduction rate, C l-blow is the train lift coefficient under blowing conditions, C l-ori is the train lift coefficient without air blowing.

[0088] Figure 4-6 It is the curve of aerodynamic drag / aerodynamic lift changing with blowing speed when a certain marshaling model train runs at a certain speed and air blowing holes are set on the streamlined head surfaces of the leading and trailing cars of the train.

[0089] Establish a numerical simulation model or conduct a wind tunnel test to study the effect of different blowing / inhaling angles on the aerodynamic drag reduction rate of the train. The blowing / inhaling angle θ is the angle between the vertical direction and the blowing direction. The tangent value of the blowing / inhaling angle θ is the ratio of the vertical distance h0 from the blowing hole to the horizontal axis where the blowing focus is located to the distance L from the blowing focus to the nose of the train, that is:

[0090]

[0091] like Figure 8As shown in the figure, by changing the position of the focus F (F1~F4) from the nose of the train to change the blowing / inhaling angle, the changes in the pressure distribution on the train surface and the wake structure are observed, and the aerodynamic parameters of the train at different blowing / inhaling angles, including the friction drag coefficient, the pressure difference drag coefficient and the surface pressure coefficient, are recorded. The experimental results are analyzed, and a mathematical model or relationship between the blowing / inhaling angle and the drag reduction rate is established. The degree of influence of the blowing / inhaling angle on the drag reduction rate is determined by statistical methods. It can be seen that the wake vortex structure has been significantly improved. After determining the relationship between the blowing / inhaling angle and the drag reduction rate, the drag of the train can be controlled by adjusting the blowing / inhaling angle. For specific operating conditions, according to the relationship between the blowing / inhaling angle and the drag reduction rate obtained by the mathematical model or experimental results, the optimal blowing / inhaling angle is selected to achieve the goal of drag reduction. The adjustable components in the blowing / inhaling system, such as the direction control device of the blowing / inhaling port, are controlled by the electric hydraulic system to achieve the adjustment of the blowing / inhaling angle. The numerical simulation results show that as the distance between the blowing focus and the nose of the train decreases, the wake flow direction is closer to the train surface, and the drag reduction performance is better.

[0092] The aerodynamic drag reduction rate ε is obtained through numerical simulation d The relationship between the focal distance L is:

[0093] ε d =0.04L 2 -1.32L+15.88

[0094] Step 106: construct an active blowing / inhalation control parameter change database based on the aerodynamic drag reduction rates at different blowing / inhalation speeds at different vehicle speeds and the relationship between the aerodynamic drag reduction rates and the blowing / inhalation angles.

[0095] It should be noted that based on the relationship between the aerodynamic drag reduction rate and the blowing / inhalation angle, the effects of different running speeds (incoming wind speed) and different blowing / inhalation speeds and different blowing / inhalation angles on the surface pressure of the high-speed train and the surrounding air velocity and pressure are analyzed; based on the air velocity streamline distribution and turbulent structure near the train, the effects of different blowing speeds / different blowing forms / different blowing angles on the flow field structure near the train, as well as the development and evolution laws of turbulence, are analyzed to determine the optimal blowing / inhalation speeds and blowing / inhalation angles at different running speeds. Figure 7 It refers to the changes of turbulence near a certain type of train when it runs at a certain speed and air holes are set on the streamlined head surfaces of the leading and trailing cars of the train.

[0096] Based on the above analysis results, the correspondence between the aerodynamic drag reduction rate of high-speed trains and the optimal blowing / inhalation speed and the optimal blowing / inhalation angle under different running speeds and different blowing speeds is obtained, and a database of changes in train active blowing / inhalation control parameters is constructed.

[0097] Step 107: Based on the active blowing / inhalation control parameter change database, active aerodynamic drag reduction control is performed on the train.

[0098] It should be noted that the active blowing / inhalation control parameter change database contains the correspondence between the aerodynamic drag reduction rate and the optimal blowing / inhalation speed and the optimal blowing / inhalation angle. Therefore, the train can be actively controlled for aerodynamic drag reduction based on the active blowing / inhalation control parameter change database. Specifically, first obtain the train speed data, query the active blowing / inhalation control parameter change database based on the train speed data, obtain the optimal blowing / inhalation speed and the optimal blowing / inhalation angle, transmit the optimal blowing / inhalation speed and the optimal blowing / inhalation angle to the train fan control system, and control the fan speed and direction through the fan control system to achieve the optimal blowing / inhalation speed and the optimal blowing / inhalation angle, and perform active aerodynamic drag reduction control on the train. The drag reduction effect is as follows: Fig. 9 and Fig.10 shown.

[0099] The active train drag reduction method provided by the present invention establishes a numerical calculation model of the train's open-line aerodynamic drag, analyzes the sudden changes in turbulent flow fields caused by the train at different running speeds and the aerodynamic drag results of the train, analyzes the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure based on the numerical results of the train's aerodynamic drag, determines the blowing / inhaling control area on the streamlined head surface of the train's head car and / or tail car, sets one or more blowing / inhaling holes in the blowing / inhaling control area, analyzes the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds, determines the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle, constructs an active blowing / inhaling control parameter change database, performs active aerodynamic drag reduction control on the train, avoids the problem that the drag reduction effect of the drag reduction method by increasing the length of the streamlined head of the train is limited, and solves the technical problem that the existing train aerodynamic drag reduction method is not effective and it is difficult to reduce the energy consumption of high-speed train operation.

[0100] For easier understanding, see Fig.11 The present invention provides an embodiment of a train active drag reduction system, comprising:

[0101] Modeling module, used to construct train geometry model and numerical calculation model of train open line aerodynamic resistance;

[0102] An aerodynamic characteristic calculation module is used to calculate the numerical result of the train aerodynamic resistance based on the train geometry model and the train open line aerodynamic resistance numerical calculation model;

[0103] The aerodynamic characteristics result analysis module is used to analyze the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure based on the numerical results of the train aerodynamic resistance;

[0104] A blowing / suction control area acquisition module is used to determine the blowing / suction control area of ​​the streamlined head surface of the leading car and / or the trailing car of the train according to the train geometric model and the relationship analysis result between the train surface pressure and the surrounding air flow velocity and the surrounding air pressure, and to set one or more blowing / suction holes in the blowing / suction control area;

[0105] The blowing / inhaling speed angle analysis module is used to obtain the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds based on the blowing / inhaling control area on the train surface, and determine the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle;

[0106] The blowing / inhalation control parameter database module is used to construct an active blowing / inhalation control parameter change database based on the aerodynamic drag reduction rate at different blowing / inhalation speeds at different running vehicle speeds and the relationship between the aerodynamic drag reduction rate and the blowing / inhalation angle;

[0107] The drag reduction control module is used to perform active aerodynamic drag reduction control on the train based on the active blowing / inhalation control parameter change database.

[0108] The relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure is:

[0109]

[0110]

[0111]

[0112] Among them, C d is the drag coefficient, C l is the lift coefficient, C p is the surface pressure coefficient, F x is the resistance of the train body, F z is the lift force on the train body, P is the surface pressure of the train, ρ is the air density, U t is the train speed, P0 is the air pressure, and A is the reference area.

[0113] The calculation formula of aerodynamic drag reduction rate is:

[0114]

[0115] Among them, ε d is the aerodynamic drag reduction rate, C d-blow is the train resistance coefficient under blowing conditions, C d-ori is the train resistance coefficient without air blowing.

[0116] The relationship between aerodynamic drag reduction rate and blowing / inhaling angle is:

[0117]

[0118] ε d =0.04L 2 -1.32L+15.88

[0119] Among them, θ is the blowing angle, h0 is the vertical distance between the blowing hole and the horizontal axis where the blowing focus is located, and L is the distance between the blowing focus and the nose tip of the train.

[0120] The drag reduction control module is specifically used for:

[0121] Get train speed data;

[0122] According to the train speed data, query the active blowing / inhalation control parameter change database to obtain the optimal blowing / inhalation speed and the optimal blowing / inhalation angle;

[0123] The optimal blowing / inhalation speed and the optimal blowing / inhalation angle are transmitted to the train fan control system, and the fan control system controls the fan speed and direction to achieve the optimal blowing / inhalation speed and the optimal blowing / inhalation angle respectively, thereby performing active aerodynamic drag reduction control on the train.

[0124] The active train drag reduction system provided in the present invention is used to execute the active train drag reduction method provided in the present invention. Its principle and technical effects are the same as those of the active train drag reduction method provided in the present invention, and will not be repeated here.

[0125] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A train active drag reduction method, characterized in that: include: Construct train geometry model and numerical calculation model of train open line aerodynamic drag; Calculate the numerical results of the train's aerodynamic drag based on the train's geometric model and the train's open-line aerodynamic drag numerical calculation model; Based on the numerical results of train aerodynamic drag, the relationship between train surface pressure and surrounding air velocity and surrounding air pressure is analyzed; According to the train geometric model, based on the analysis result of the relationship between the train surface pressure and the surrounding air flow velocity and the surrounding air pressure, determine the blowing / suction control area of ​​the streamlined head surface of the train head car and / or the tail car, and set one or more blowing / suction holes in the blowing / suction control area; Based on the blowing / inhaling control area on the train surface, the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds is obtained, and the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle is determined; Based on the aerodynamic drag reduction rate at different blowing / inhalation speeds at different running speeds and the relationship between the aerodynamic drag reduction rate and the blowing / inhalation angle, a database of active blowing / inhalation control parameter changes is constructed; Based on the active blowing / inhalation control parameter change database, active aerodynamic drag reduction control is performed on the train.

2. The train active drag reduction method according to claim 1, characterized in that: The relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure is: Among them, C d is the drag coefficient, C l is the lift coefficient, C p is the surface pressure coefficient, F x is the resistance of the train body, F z is the lift force on the train body, P is the surface pressure of the train, ρ is the air density, U t is the train speed, P0 is the air pressure, and A is the reference area.

3. The train active drag reduction method according to claim 2, characterized in that: The calculation formula of aerodynamic drag reduction rate is: Among them, ε d is the aerodynamic drag reduction rate, C d-blow is the train resistance coefficient under blowing conditions, C d-ori is the train resistance coefficient without air blowing.

4. The train active drag reduction method according to claim 3, characterized in that: The relationship between aerodynamic drag reduction rate and blowing / inhaling angle is: e d =0.04L 2 -1.32L+15.88 Among them, θ is the blowing angle, h0 is the vertical distance between the blowing hole and the horizontal axis where the blowing focus is located, and L is the distance between the blowing focus and the nose tip of the train.

5. The train active drag reduction method according to claim 1, characterized in that: Based on the active blowing / inhaling control parameter change database, active aerodynamic drag reduction control is performed on the train, including: Get train speed data; According to the train speed data, query the active blowing / inhalation control parameter change database to obtain the optimal blowing / inhalation speed and the optimal blowing / inhalation angle; The optimal blowing / inhalation speed and the optimal blowing / inhalation angle are transmitted to the train fan control system, and the fan control system controls the fan speed and direction to achieve the optimal blowing / inhalation speed and the optimal blowing / inhalation angle respectively, thereby performing active aerodynamic drag reduction control on the train.

6. A train active drag reduction system, characterized in that: include: Modeling module, used to construct train geometry model and numerical calculation model of train open line aerodynamic resistance; An aerodynamic characteristic calculation module is used to calculate the numerical result of the train aerodynamic resistance based on the train geometry model and the train open line aerodynamic resistance numerical calculation model; The aerodynamic characteristics result analysis module is used to analyze the relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure based on the numerical results of the train aerodynamic resistance; A blowing / suction control area acquisition module is used to determine the blowing / suction control area of ​​the streamlined head surface of the leading car and / or the trailing car of the train according to the train geometric model and the relationship analysis result between the train surface pressure and the surrounding air flow velocity and the surrounding air pressure, and to set one or more blowing / suction holes in the blowing / suction control area; The blowing / inhaling speed angle analysis module is used to obtain the aerodynamic drag reduction rate at different blowing / inhaling speeds at different running speeds based on the blowing / inhaling control area on the train surface, and determine the relationship between the aerodynamic drag reduction rate and the blowing / inhaling angle; The blowing / inhalation control parameter database module is used to construct an active blowing / inhalation control parameter change database based on the aerodynamic drag reduction rate at different blowing / inhalation speeds at different running vehicle speeds and the relationship between the aerodynamic drag reduction rate and the blowing / inhalation angle; The drag reduction control module is used to perform active aerodynamic drag reduction control on the train based on the active blowing / inhalation control parameter change database.

7. The train active drag reduction system according to claim 6, characterized in that: The relationship between the train surface pressure and the surrounding air velocity and the surrounding air pressure is: Among them, C d is the drag coefficient, C l is the lift coefficient, C p is the surface pressure coefficient, F x is the resistance of the train body, F z is the lift force on the train body, P is the surface pressure of the train, ρ is the air density, U t is the train speed, P0 is the air pressure, and A is the reference area.

8. The train active drag reduction system according to claim 7, characterized in that: The calculation formula of aerodynamic drag reduction rate is: Among them, ε d is the aerodynamic drag reduction rate, C d-blow is the train resistance coefficient under blowing conditions, C d-ori is the train resistance coefficient without air blowing.

9. The train active drag reduction system according to claim 8, characterized in that: The relationship between aerodynamic drag reduction rate and blowing / inhaling angle is: e d =0.04L 2 -1.32L+15.88 Among them, θ is the blowing angle, h0 is the vertical distance between the blowing hole and the horizontal axis where the blowing focus is located, and L is the distance between the blowing focus and the nose tip of the train.

10. The train active drag reduction system according to claim 6, characterized in that: The drag reduction control module is specifically used for: Get train speed data; According to the train speed data, query the active blowing / inhalation control parameter change database to obtain the optimal blowing / inhalation speed and the optimal blowing / inhalation angle; The optimal blowing / inhalation speed and the optimal blowing / inhalation angle are transmitted to the train fan control system, and the fan control system controls the fan speed and direction to achieve the optimal blowing / inhalation speed and the optimal blowing / inhalation angle respectively, thereby performing active aerodynamic drag reduction control on the train.

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