A jet drag reduction structure for subway train body

Abstract

The present invention discloses a jet drag reduction structure for a subway train body, comprising a train body and an upturned inclined plate, wherein the upturned inclined plate and the roof surface of the train body enclose a main jet channel, and the main jet channel gradually tilts downward in the direction of the rear of the train body; a jet inlet is arranged at the rear end of the main jet channel away from the train body, and a first jet channel and a second jet channel are arranged in sequence from top to bottom at the rear end of the main jet channel close to the train body. The present invention greatly reduces the vortex area above the rear of the train and makes the reverse vortex below the rear of the train disappear, greatly reducing the resistance of the train when it is moving; the jet drag reduction of the rear of the train can be completed without separately arranging a jet source in the train; and the travel resistance of the train when it is running is minimized by reasonably designing the parameters of the jet structure at the rear of the train.

Description

Technical Field

[0001] The invention relates to the field of rail transportation, and in particular to a jet drag reduction structure for a subway train body. Background Art

[0002] Rail transit refers to a type of transportation vehicle or transportation system in which operating vehicles need to travel on specific tracks. Urban rail transit trains run on fully enclosed lines. Lines in the central urban area are basically located in underground tunnels, and lines outside the central urban area are generally located on viaducts or on the ground. It has the advantages of saving ground space, reducing ground noise, large transportation capacity, high speed, safety and punctuality, low cost, energy saving, and comfortable and convenient riding. With the continuous increase in train running speed, passenger capacity, and transportation distance, train energy consumption has increased significantly, posing new challenges to energy conservation and environmental protection.

[0003] At present, the energy consumption during train operation is mainly used to overcome the running resistance. The air resistance of the train in high-speed operation increases sharply with the square of the speed, which is the main consideration restricting the drag reduction and energy saving of high-speed trains. How to reduce the running resistance of trains has always been an urgent problem to be solved. At present, the research on aerodynamic drag reduction of rail trains is all aimed at the head design and local structure optimization of high-speed trains. Although some progress has been made and the running resistance of trains has been reduced to a certain extent, it is difficult for traditional drag reduction technology to make new major breakthroughs due to the manufacturing process.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] In view of the problems in the related art, the present invention proposes a jet drag reduction structure for a subway train body to overcome the above technical problems existing in the existing related art.

[0006] To this end, the specific technical solution adopted by the present invention is as follows:

[0007] A jet drag reduction structure for a subway train body comprises a train body, wherein an upturned inclined plate is arranged on the top of the train body, the upturned inclined plate and the roof surface of the train body enclose a main jet channel, and the main jet channel gradually tilts downward in the direction close to the rear of the train body; a jet inlet is arranged at one end of the main jet channel away from the rear of the train body, and a first jet channel and a second jet channel are arranged in sequence from top to bottom at one end of the main jet channel close to the rear of the train body.

[0008] Furthermore, in order to make the jet ejected from the rear of the train, the jet structure at the rear of the train is used to greatly reduce the vortex area above the rear of the train and make the reverse vortex below the rear of the train disappear, thereby greatly reducing the resistance of the train when it is moving. The first jet channel and the second jet channel are both arranged to gradually tilt downward along the direction of the rear of the train close to the train body, and the first jet channel and the second jet channel are respectively provided with a first jet outlet and a second jet outlet at one end of the rear of the train close to the train body.

[0009] Furthermore, in order to allow external air to enter the main jet channel, the opening of the jet inlet faces the forward direction of the train body, and the external air of the train body is the jet source.

[0010] Furthermore, in order to make the jet ejected from the rear of the train, the jet structure at the rear of the train greatly reduces the vortex area above the rear of the train, and makes the reverse vortex below the rear of the train disappear, thereby greatly reducing the resistance of the train when moving. The first jet outlet and the second jet outlet are both located at the rear of the train body; the first jet outlet is located above the second jet outlet, and the opening of the first jet outlet is inclined downward, and the opening of the second jet outlet is inclined upward; the outlet jets of the first jet outlet and the second jet outlet intersect.

[0011] Furthermore, in order to maximize the reduction of the running resistance of the train, the inlet area of ​​the jet inlet is S1, the outlet area of ​​the first jet outlet is S2, and the outlet area of ​​the second jet outlet is S3;

[0012] Among them, S1 / S2=2-5;

[0013] S1 / S3=2-5;

[0014] S2 / S3=0.5-1.8.

[0015] Furthermore, in order to minimize the running resistance of the train, the angle between the upward inclined plate and the horizontal plane is α1 = 1-7°;

[0016] The angle between the jet direction of the first jet outlet and the horizontal plane is β1=8-10°;

[0017] The included angle β2 between the jet direction of the second jet outlet and the plumb line is 2-18°.

[0018] Furthermore, the distance between the first jet outlet and the top surface of the train body is h1;

[0019] h1 / H=0.02-0.3;

[0020] The distance between the second jet outlet and the top surface of the train body is h2;

[0021] h2 / H=0.4-0.98;

[0022] Where H is the train height.

[0023] Furthermore, in order to minimize the running resistance of the train during operation, the jet inlet, the first jet outlet and the second jet outlet are all rectangular, and the long side of the rectangle is parallel to the roof of the train body.

[0024] Furthermore, in order to minimize the running resistance of the train during operation, rectifier plates are evenly arranged in the first jet channel and the second jet channel along the jet flow direction.

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention arranges a first jet channel and a second jet channel in the train, and the jets in the first jet channel and the second jet channel are ejected from the rear of the train. The jet structure at the rear of the train greatly reduces the vortex area above the rear of the train and makes the reverse vortex below the rear of the train disappear, thereby greatly reducing the resistance of the train when it is moving.

[0027] (2) The present invention provides an upward inclined plate on the top of the train. When the train is running at high speed, the air outside the train can form a high-speed jet and enter the main jet channel. The jet drag reduction at the rear of the train can be achieved without arranging a separate jet source in the train.

[0028] (3) The present invention minimizes the running resistance of the train by rationally designing the structural parameters of the jet at the rear of the train. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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 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 drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 is a schematic structural diagram of a jet drag reduction structure for a subway train body according to an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of a jet channel in a jet drag reduction structure of a subway train body according to an embodiment of the present invention;

[0032] Figure 3 is a numerical simulation diagram of the jet flow of the jet channel of the present invention;

[0033] Figure 4 It is the velocity cloud diagram of the jet channel of the present invention;

[0034] Figure 5Schematic diagram of drag reduction rate under different speed ratios of the present invention;

[0035] Figure 6 This is a simulation diagram of the vortex area at the tail of an existing train when the present invention does not include a jet channel;

[0036] Figure 7 This is a simulation diagram of the vortex area at the tail of the train after the jet channel is added in the present invention.

[0037] Figure 8 The figure is a schematic diagram of the position of a rectifier plate in a jet drag reduction structure of a subway train body according to an embodiment of the present invention.

[0038] In the figure:

[0039] 1. Train body; 2. Upward inclined plate; 3. Main jet channel; 4. Jet inlet; 5. First jet channel; 6. Second jet channel; 7. First jet outlet; 8. Second jet outlet. DETAILED DESCRIPTION

[0040] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention, and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The described embodiments are 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 the field without creative work are within the scope of protection of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0041] According to an embodiment of the present invention, a jet drag reduction structure for a subway train body is provided.

[0042] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. Figure 1 and Figure 8As shown, the jet drag reduction structure of the subway train body according to an embodiment of the present invention includes a train body 1, an upturned inclined plate 2 is arranged on the top of the train body 1, the upturned inclined plate 2 and the roof surface of the train body 1 are enclosed to form a main jet channel 3, and the main jet channel 3 is gradually inclined downward along the direction close to the rear of the train body 1; a jet inlet 4 is arranged at the end of the main jet channel 3 away from the rear of the train body 1, and a first jet channel 5 and a second jet channel 6 are arranged in sequence from top to bottom at the end of the main jet channel 3 close to the rear of the train body 1. Wherein, when the train moves forward, external air can enter the main jet channel 3 through the jet inlet 4 to form a jet. An active jet source can also be added to the main jet channel 3 in the train to spray air into the main jet channel 3 to replace the air actively injected from the outside. To facilitate understanding of the outlet flow direction, Figure 2 The jet outlets in the first jet channel 5 and the second jet channel 6 are all extended outward to a certain extent. The channel width and the projection position along the vertical direction are consistent.

[0043] In one embodiment, the first jet channel 5 and the second jet channel 6 are both configured to gradually tilt downward along the direction of the rear of the train body 1, and the first jet channel 5 and the second jet channel 6 are respectively provided with a first jet outlet 7 and a second jet outlet 8 at one end of the first jet channel 5 and the second jet channel 6 close to the rear of the train body 1; usually the tail end of the second jet channel 6 is designed to be a V-shaped arc surface so that the outlet jet of the second jet outlet 8 can be tilted upward, so that the jet is ejected from the rear of the train, and through the jet structure at the rear of the train, the vortex area above the rear of the train is greatly reduced, and the reverse vortex below the rear of the train disappears, thereby greatly reducing the resistance of the train when it is moving.

[0044] In one embodiment, the opening of the jet inlet 4 faces the forward direction of the train body 1, and the external air of the train body 1 is the jet source, so that the external air enters the main jet channel.

[0045] In one embodiment, the first jet outlet 7 and the second jet outlet 8 are both located at the rear of the train body 1 .

[0046] Among them, the first jet outlet 7 is located above the second jet outlet 8, and the opening of the first jet outlet 7 is inclined downward, and the opening of the second jet outlet 8 is inclined upward; there is an intersection between the outlet jets of the first jet outlet 7 and the second jet outlet 8, so that the jet is ejected from the rear of the train, and passes through the jet structure at the rear of the train, which greatly reduces the vortex area above the rear of the train and makes the reverse vortex below the rear of the train disappear, thereby greatly reducing the resistance of the train when it is moving.

[0047] In one embodiment, the inlet area of ​​the jet inlet 4 is S1, the outlet area of ​​the first jet outlet 7 is S2, and the outlet area of ​​the second jet outlet 8 is S3;

[0048] Among them, S1 / S2=2-5;

[0049] S1 / S3=2-5;

[0050] S2 / S3=0.5-1.8.

[0051] In one embodiment, the angle α1 between the upward-curved inclined plate 2 and the horizontal plane is 1-7°;

[0052] The angle β1 between the outlet jet direction of the first jet outlet 7 and the horizontal plane is 8-10°;

[0053] The angle β2 between the outlet jet direction of the second jet outlet 8 and the plumb line is 2-18°.

[0054] In one embodiment, the distance between the first jet outlet 7 and the top surface of the train body 1 is h1;

[0055] h1 / H=0.02-0.3;

[0056] The distance between the second jet outlet 8 and the top surface of the train body 1 is h2;

[0057] h2 / H=0.4-0.98;

[0058] Where H is the train height.

[0059] In one embodiment, the openings of the jet inlet 4 , the first jet outlet 7 and the second jet outlet 8 are all rectangular, and the long sides of the rectangles are parallel to the roof of the train body 1 .

[0060] In one embodiment, the first jet channel 5 and the second jet channel 6 are evenly provided with rectifier plates along the jet flow direction, thereby maximizing the reduction of the running resistance of the train. The jet inlet 4, the first jet outlet 7 and the second jet outlet 8 have equal mouth widths and are all rectangular, with the long side of the rectangle parallel to the roof of the train. In order to improve the fluid flow stability in the first jet channel 5 and the second jet channel 6, 2-5 rectifier plates are evenly provided in the first jet channel 5 and the second jet channel 6 along the jet flow direction, such as Figure 8 As shown in FIG. 1 , the main jet channel 3 , the first jet channel 5 and the second jet channel 6 are all provided with rectifying plates.

[0061] See also Figure 3 The CFD technology is used to numerically simulate the jet flow, and the velocity flow field distribution is shown in the figure. The velocity streamlines in the entire jet structure are evenly distributed. The velocity cloud diagram of the entire jet structure is shown in the figure. Figure 4 As shown, the velocity cloud diagram is evenly distributed, and there is no local velocity increase or decrease at the first jet outlet 7 and the second jet outlet 8, and the outlet velocity is evenly distributed.

[0062] By rationally designing various parameters, the speed ratio of the first jet outlet 7 to the jet inlet 4 can be maintained at approximately 0.25, and the speed ratio of the second jet outlet 8 to the jet inlet 4 can be maintained at approximately 0.25. Figure 5 As shown, the horizontal axis is the speed ratio of the first jet outlet 7 to the jet inlet 4, and the three curves from top to bottom are the curve diagrams when the speed ratio of the second jet outlet 8 to the jet inlet 4 is 0.25, 0.15, and 0.05. After calculation, when the speed ratio of the first jet outlet 7 to the jet inlet 4 and the speed ratio of the second jet outlet 8 to the jet inlet 4 are both 0.25, the train drag reduction rate reaches the highest 16.5%.

[0063] like Figure 6 As shown in the figure, without the jet solution of the present invention, an obvious local vortex area is generated above the rear of the train, and the range of the vortex area is relatively large. There is also a vortex motion opposite to that above the rear near the rear of the train, which directly leads to an increase in the uniformly distributed low pressure at the rear of the train and increases the resistance of the train during operation. Figure 7 As shown, after adding the jet solution of the present invention, the vortex area above the tail of the train is significantly reduced, and the reverse vortex below the tail of the train disappears, and the running resistance of the train is greatly reduced.

[0064] In summary, the present invention sets a first jet channel and a second jet channel in the train, and the jets in the first jet channel and the second jet channel are ejected from the rear of the train, and pass through the jet structure at the rear of the train, which greatly reduces the vortex area above the rear of the train, and makes the reverse vortex below the rear of the train disappear, thereby greatly reducing the resistance of the train when it is moving. The present invention sets an upward inclined plate on the top of the train, so that when the train is moving at high speed, the air outside the train can form a high-speed jet and enter the main jet channel, and the jet drag reduction at the rear of the train can be completed without arranging a jet source separately in the train. The present invention minimizes the travel resistance of the train when it is running by rationally designing the parameters of the jet structure at the rear of the train.

[0065] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0066] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A jet drag reduction structure for a subway train body, comprising a train body (1), characterized in that: An upward-curved inclined plate (2) is arranged on the top of the train body (1), the upward-curved inclined plate (2) and the roof surface of the train body (1) enclose a main jet channel (3), and the main jet channel (3) gradually slopes downward in a direction close to the rear of the train body (1); The main jet channel (3) is provided with a jet inlet (4) at one end away from the rear of the train body (1), and the main jet channel (3) is provided with a first jet channel (5) and a second jet channel (6) in sequence from top to bottom at one end close to the rear of the train body (1); The first jet channel (5) and the second jet channel (6) are both arranged to gradually tilt downward in a direction close to the rear of the train body (1), and the first jet channel (5) and the second jet channel (6) are respectively provided with a first jet outlet (7) and a second jet outlet (8) at one end close to the rear of the train body (1); The first jet outlet (7) is located above the second jet outlet (8), and the opening of the first jet outlet (7) is inclined downward, while the opening of the second jet outlet (8) is inclined upward; The outlet jets of the first jet outlet (7) and the second jet outlet (8) intersect.

2. The jet drag reduction structure of a subway train body according to claim 1, characterized in that: The opening of the jet inlet (4) faces the forward direction of the train body (1), and the external air of the train body (1) is the jet source.

3. The jet drag reduction structure for a subway train body according to claim 2, characterized in that: The first jet outlet (7) and the second jet outlet (8) are both located at the rear of the train body (1).

4. The jet drag reduction structure for a subway train body according to claim 1, characterized in that: The inlet area of ​​the jet inlet (4) is S1, the outlet area of ​​the first jet outlet (7) is S2, and the outlet area of ​​the second jet outlet (8) is S3; Among them, S1 / S2=2-5; S1 / S3=2-5; S2 / S3=0.5-1.

8.

5. The jet drag reduction structure of a subway train body according to claim 4, characterized in that: The angle α1 between the upward-curved inclined plate (2) and the horizontal plane is 1-7°; The angle β1 between the jet direction of the first jet outlet (7) and the horizontal plane is 8-10°; The included angle β2 between the jet direction of the second jet outlet (8) and the plumb line is 2-18°.

6. The jet drag reduction structure for a subway train body according to claim 5, characterized in that: The distance between the first jet outlet (7) and the top surface of the train body (1) is h1; h1 / H=0.02-0.3; The distance between the second jet outlet (8) and the top surface of the train body (1) is h2; h2 / H=0.4-0.98; Where H is the train height.

7. The jet drag reduction structure for a subway train body according to claim 6, characterized in that: The jet inlet (4), the first jet outlet (7) and the second jet outlet (8) are all rectangular, and the long sides of the rectangle are parallel to the roof of the train body (1).

8. The jet drag reduction structure for a subway train body according to claim 7, characterized in that: Rectifier plates are evenly arranged in the first jet channel (5) and the second jet channel (6) along the jet flow direction.

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