SLOT DEVICE FOR HIGH-SPEED TRAIN DRAG-CONTROL

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese Patent Application No. 202411519907.9, filed on Oct. 29, 2024, which is herein incorporated by reference in its entirety.

TECHNICAL FIELD

The disclosure relates to the field of aerodynamics technologies, and more particularly to a slot device for high-speed train drag-control.

BACKGROUND

At present, drag-control of a high-speed train primarily employs aerodynamic braking methods, which improve braking efficiency by increasing air drag. A common aerodynamic braking method is to use an external aerodynamic brake panel arranged on a top or a side of a body of the high-speed train. However, the external aerodynamic brake panel is bulky and complex in structure, which imposes stringent requirements on structure and strength, and increases operational complexity of the high-speed train. As a result, the external aerodynamic brake panel fails to meet the needs for short-distance braking during high-speed operation of the high-speed train.

SUMMARY

In view of existing problems in the related art, the disclosure provides a slot device for high-speed train drag-control, which can effectively solve the above-mentioned problems.

The technical solution adopted by the disclosure is as follows.

The disclosure provides a slot device for high-speed train drag-control, which includes a left slot and a right slot symmetrically arranged with respect to a center plane of a body of a train (i.e., high-speed train). The left slot and the right slot are symmetrically arranged on two inner side surfaces of a head of the train. Each of the left slot and the right slot includes a slot inlet and a slot outlet. The slot inlet is arranged in a region on a side of a nose tip of the train, and the slot outlet is arranged in a flat section region on a top of the head of the train. When the train brakes, the slot inlets of the left slot and the right slot are opened, so that airflow is diverted through the left slot and the right slot and ejected from the slot outlets of the left slot and the right slot, thereby increasing pressure in a region of each of the slot inlets and forming a jet wall at each of the slot outlets to cause local separation of the airflow, and thus increasing drag of the train to assist in achieving short-distance braking. That's to say, the train equipped with the slot device can increase the drag of the train to reduce braking distance.

In an embodiment, for the right slot in a forward direction of the train, the right slot includes a slot inlet control cross-section, a first slot intermediate control cross-section sec1, a second slot intermediate control cross-section sec2, a third slot intermediate control cross-section sec3 and a slot outlet control cross-section sequentially formed in that order in a direction from the slot inlet to the slot outlet.

A coordinate system and related parameters of the coordinate system are defined as follows. The nose tip of the train is taken as a coordinate origin, a length direction of the body of the train is defined as an x-axis, with a direction towards a rear of the train being positive; a width direction of the body of the train is defined as a y-axis, with a direction towards a right side of the forward direction of the train being positive; a height direction of the body of the train is defined as a z-axis, with an upward direction being positive; and W represents a width of the body of the train.

(1) A shape and a position of the slot inlet control cross-section are described as follows:

• • a. on a side of the nose tip of the train, determining coordinates of a center point O₁ as (x₁, y₁, z₁), where x₁ is 0.13 W, y₁ is 0.27 W, and z₁ is 0.13 W;
  • b. in a yoz plane, taking the center point O₁ as an ellipse center point, and determining a major axis radius as 0.15 W to 0.25 W and a minor axis radius as 0.06 W to 0.15 W, to form a first ellipse; and
  • c. from a perspective of the positive direction of the x-axis, rotating the first ellipse clockwise around the x-axis with the center point O₁ by 0° to 45° to form a second ellipse;
  • where the second ellipse is configured to control a shape of the slot inlet, and an elliptical plane where the second ellipse is located is the slot inlet control cross-section; and where a method for controlling the shape of the slot inlet includes: forming a slot inlet intersection surface by intersecting a cylindrical formed by the second ellipse along the x-axis with a surface of the body of the train.

(2) A shape and a position of the first slot intermediate control cross-section sec1 are described as follows:

• • translating and proportionally scaling down the second ellipse to form the first slot intermediate control cross-section sec1, including:
    • a. translating the second ellipse to make the center point O₁ of the second ellipse translate from the coordinates (x₁, y₁, z₁) to coordinates (x₂, y₂, z₂), to obtain a translated second ellipse, where x₂=x₁+Δx₁, Δx₁ is in a range of 0.07 W to 0.67 W, y₂ is 0.27 W, and z₂ is 0.13 W; and making a position of the coordinates (x₂, y₂, z₂) as a center point O₂, and taking the translated second ellipse as a third ellipse; and
    • b. proportionally scaling down the third ellipse with a scaling factor ranging from 70% to 95% to obtain the first slot intermediate control cross-section sec1.

(3) A shape and a position of the second slot intermediate control cross-section sec2 are described as follows:

• • a. determining coordinates of a center point O₃ as (x₃, y₃, z₃), where x₃=x₁+Δx₂, Δx₂ is in a range of 0.77 W to 1.77 W, y₃ is 0.35 W, and z₃ is 0.15 W;
  • b. in the yoz plane, taking the center point O₃ as an ellipse center point, and determining a major axis radius as 0.12 W to 0.22 W and a minor axis radius as 0.05 W to 0.12 W, to form a fourth ellipse; and
  • c. from a perspective of a negative direction of the y-axis, rotating the fourth ellipse clockwise around the y-axis with the center point O₃ by 15° to 45° to form the second slot intermediate control cross-section sec2.

(4) A shape and a position of the third slot intermediate control cross-section sec3 are described as follows:

• • a. determining coordinates of a center point O₄ as (x₄, y₄, z₄), where x₄=x₁+Δx₃, Δx₃ is in a range of 1.77 W to 3.33 W, y₄ is 0.23 W, z₄=z₁+Δz₃, and Δz₃ is in a range of 0.07 W to 0.67 W;
  • b. in an xoy plane, taking the center point O₄ as an ellipse center point, and determining a major axis radius as 0.06 W to 0.12 W and a minor axis radius as 0.01 W to 0.06 W, to form a fifth ellipse; and
  • c. from the perspective of the positive direction of the x-axis, rotating the fifth ellipse clockwise around the x-axis with the center point O₄ by −15° to 15° to form the third slot intermediate control cross-section sec3.

(5) A shape and a position of the slot outlet control cross-section are described as follows;

• • defining the slot outlet on a range where an included angle between a top plane of the train behind a front windshield of the head of the train and the xoy plane is less than 10°, with a cross-section shape is a waist-shaped hole, where the waist-shape hole is parallel to the xoy plane, and coordinates of a center point Og of the waist-shaped hole is (x₅, y₅, z₅), x₅ is 2.08 W, y₅ is 0.23 W, and z₅ is 0.91 W; determining a length of the waist-shaped hole as 0.3 W to 0.45 W, and a width of the waist-shaped hole as 0.02 W to 0.1 W, to form the slot outlet control cross-section.

In an embodiment, a built-in movable curved plate is disposed at the slot inlet, and a built-in movable flat plate is disposed at the slot outlet. The built-in movable curved plate is configured to close or open the slot inlet, and the built-in movable flat plate is configured to close or open the slot outlet.

The slot device for high-speed train drag-control has the following advantages.

The slot device for high-speed train drag-control provided by the disclosure utilizes aerodynamic principles to design two symmetrical slot configurations in the head of the train. The slot device designed by the disclosure can significantly increase the drag of the train and effectively reducing braking distance. A control method of the slot device of the disclosure is simple, and it represents an effective drag-control approach, meeting the need for short-distance braking during high-speed operation of the train.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a schematic diagram of a layout of a left slot and a right slot on a body of a train of the disclosure.

FIG. 2 illustrates a schematic diagram of one of the left slot and the right slot of the disclosure.

FIG. 3 illustrates a schematic diagram of a shape and a layout position of a slot inlet control cross-section of the disclosure.

FIG. 4 illustrates a schematic diagram of a shape and a layout position of a first slot intermediate control cross-section sec1 of the disclosure.

FIG. 5 illustrates a schematic diagram of a shape and a layout position of a second slot intermediate control cross-section sec2 of the disclosure.

FIG. 6 illustrates a schematic diagram of a shape and a layout position of a third slot intermediate control cross-section sec3 of the disclosure.

FIG. 7 illustrates a schematic diagram of a shape and a layout position of a slot outlet control cross-section of the disclosure.

FIG. 8 illustrates a schematic diagram showing the left slot and the right slot in a closed position of the disclosure.

FIG. 9 illustrates a schematic diagram showing the left slot and the right slot in an open position of the disclosure.

DESCRIPTION OF REFERENCE SIGNS

• • 1—left slot; 2—right-slot; A1—slot inlet control cross-section; B-slot inlet intersection surface; A2—first slot intermediate control cross-section sec1; A3—second slot intermediate control cross-section sec2; A4—third slot intermediate control cross-section sec3; A5—slot outlet control cross-section; 3—slot inlet; 4—slot outlet; 5—built-in movable curved plate; 6—built-in movable flat plate; 7—train (i.e., high-speed train); 71—body of train; 72—head of train; 73—nose tip of train; 74—front windshield.

DETAILED DESCRIPTION OF EMBODIMENTS

To make technical problems solved by the disclosure, technical solutions, and beneficial effects clearer and more understandable, the disclosure will be further described in detail with reference to attached drawings and embodiments. It should be understood that specific embodiments described herein are only intended to illustrate the disclosure and are not intended to limit the disclosure.

Without affecting a normal operation of a high-speed train, and to solve a key problem of achieving short-distance braking during a high-speed operation of the high-speed train, the disclosure provides a slot device for high-speed train drag-control. Based on an existing shape of the high-speed train, the disclosure taps into internal potential and utilizes aerodynamic principles to design two symmetrical slot configurations in a head of the high-speed train. This design allows airflow to be diverted through the slots, significantly increasing pressure in a region near each slot inlet and forming a “jet wall” at each slot outlet, which causes local separation of the airflow and further increases drag of the high-speed train. When not needed, the slot inlets and slot outlets can be blocked to achieve an “on-off” function of drag-control.

Specifically, referring to FIG. 1 and FIG. 2, the disclosure provides a slot device for high-speed train drag-control, which includes a left slot 1 and a right slot 2 symmetrically arranged with respect to a center plane of a body of a train 71 (i.e., high-speed train). Specifically, the left slot 1 and the right slot 2 are symmetrically arranged on two inner side surfaces of a head of the train 72. Each of the left slot 1 and the right slot 2 includes a slot inlet 3 and a slot outlet 4. The slot inlet 3 is arranged in a region on a side of a nose tip of the train 73, and the slot outlet 4 is arranged in a flat section region on a top of the head of the train 72.

A built-in movable curved plate 5 is disposed at the slot inlet 3, and a built-in movable flat plate 6 is disposed at the slot outlet 4. Shapes of these plates are similar to an original shape of an inlet region of the body of the train 71 (i.e., the head of the train). The built-in movable curved plate 5 is configured to close or open the slot inlet 3, and the built-in movable flat plate 6 is configured to close or open the slot outlet 4. FIG. 8 illustrates a schematic showing the left slot 1 and the right slot 2 in a closed position of the disclosure. FIG. 9 illustrates a schematic diagram showing the left slot 1 and the right slot 2 in an open position of the disclosure.

Therefore, when the train 7 brakes, the slot inlets 3 of the left slot 1 and the right slot 2 are opened, so that airflow is diverted through the left slot 1 and the right slot 2 and ejected from the slot outlets 4 of the left slot 1 and the right slot 2. This process increases pressure in a region of each of the slot inlets 3 and forms a jet wall at each of the slot outlets 4 to cause local separation of the airflow, thereby increasing drag of the train 7 to assist in achieving short-distance braking.

In the disclosure, due to a symmetrical arrangement of the left slot 1 and the right slot 2, the right slot 2 in a forward direction of the train 7 is taken as an example. Referring to FIG. 3 through FIG. 7, the right slot 2 includes a slot inlet control cross-section, a first slot intermediate control cross-section sec1, a second slot intermediate control cross-section sec2, a third slot intermediate control cross-section sec3 and a slot outlet control cross-section sequentially formed in that order in a direction from the slot inlet 3 to the slot outlet 4. A shape of the right slot 2 between these five control cross-sections is smoothly transitioned by a curved surface. In the attached drawings, the slot inlet control cross-section, the first slot intermediate control cross-section sec1, the second slot intermediate control cross-section sec2, the third slot intermediate control cross-section sec3, and the slot outlet control cross-section are represented by A1, A2, A3, A4, and A5, respectively.

A coordinate system and related parameters of the coordinate system are defined as follows. The nose tip of the train 73 is taken as a coordinate origin. A length direction of the body of the train 71 is defined as an x-axis with a direction towards a rear of the train being positive. A width direction of the body of the train 71 is defined as a y-axis, with a direction towards a right side of the forward direction of the train being positive. A height direction of the body of the train 71 is defined as a z-axis, with an upward direction being positive. W represents a width of the body of the train 71.

Shapes and positions of these five control cross-sections are described as follows.

(1) Referring to FIG. 3, a shape and a position of the slot inlet control cross-section are described as follows.

• • a. On a side of the nose tip of the train 73, coordinates of a center point O₁ is determined as (x₁, y₁, z₁), where x₁ is 0.13 W, y₁ is 0.27 W, and z₁ is 0.13 W.
  • b. In a yoz plane, the center point O₁ is taken as an ellipse center point, a major axis radius is determined as 0.15 W to 0.25 W, and a minor axis radius is determined 0.06 W to 0.15 W, thereby forming a first ellipse.
  • c. From a perspective of the positive direction of the x-axis, the first ellipse is rotated clockwise around the x-axis with the center point O₁ by 0° to 45° to form a second ellipse.

The second ellipse is configured to control a shape of the slot inlet 3, and an elliptical plane where the second ellipse is located is the slot inlet control cross-section.

A method for controlling the shape of the slot inlet 3 is as follows. An intersection surface is formed by intersecting a cylindrical formed by the second ellipse along the x-axis with a surface of the body of the train 71. The intersection surface is defined as a slot inlet intersection surface, which is denoted as B in FIG. 2.

(2) Referring to FIG. 4, a shape and a position of the first slot intermediate control cross-section sec1 are described as follows.

The second ellipse is translated and scaled down proportionally to form the first slot intermediate control cross-section sec1, which includes the following specific operations.

• • a. The second ellipse is translated to make the center point O₁ of the second ellipse translate from the coordinates (x₁, y₁, z₁) to coordinates (x₂, y₂, z₂), to obtain a translated second ellipse, where x₂=x₁+Δx₁, Δx₁ is in a range of 0.07 W to 0.67 W, y₂ is 0.27 W, and z₂ is 0.13 W. Then, A position of the coordinates (x₂, y₂, z₂) is marked as a center point O₂, and the translated second ellipse is taken as a third ellipse.
  • b. The third ellipse is scaled down proportionally with a scaling factor ranging from 70% to 95% to obtain the first slot intermediate control cross-section sec1.

(3) Referring to FIG. 5, a shape and a position of the second slot intermediate control cross-section sec2 are described as follows.

• • a. Coordinates of a center point O₃ is determined as (x₃, y₃, z₃), where x₃=x₁+Δx₂, Δx₂ is in a range of 0.77 W to 1.77 W, y₃ is 0.35 W, and z₃ is 0.15 W.
  • b. In the yoz plane, the center point O₃ is taken as an ellipse center point, a major axis radius is determined as 0.12 W to 0.22 W, and a minor axis radius is determined as 0.05 W to 0.12 W, thereby forming a fourth ellipse.
  • c. From a perspective of a negative direction of the y-axis, the fourth ellipse is rotated clockwise around the y-axis with the center point O₃ by 15° to 45° to form the second slot intermediate control cross-section sec2.

(4) Referring to FIG. 6, a shape and a position of the third slot intermediate control cross-section sec3 are described as follows.

• • a. Coordinates of a center point O₄ is determined as (x₄, y₄, z₄), where x₄=x₁+Δx₃, Δx₃ is in a range of 1.77 W to 3.33 W, y₄ is 0.23 W, z₄=z₁+Δz₃, and Δz₃ is in a range of 0.07 W to 0.67 W.
  • b. In an xoy plane, the center point O₄ is taken as an ellipse center point, a major axis radius is determined as 0.06 W to 0.12 W, and a minor axis radius is determined as 0.01 W to 0.06 W, thereby forming a fifth ellipse.
  • c. From the perspective of the positive direction of the x-axis, the fifth ellipse is rotated clockwise around the x-axis with the center point O₄ by −15° to 15° to form the third slot intermediate control cross-section sec3.

(5) Referring to FIG. 7, a shape and a position of the slot outlet control cross-section are described as follows.

The slot outlet 4 is defined on range where an included angle between a top plane of the train behind a front windshield 74 of the head of the train 72 and the xoy plane is less than 10°, with a cross-section shape of a waist-shaped hole. The waist-shaped hole is parallel to the xoy plane, and coordinates of a center point Og of the waist-shaped hole is (x₅, y₅, z₅), where x₅ is 2.08 W, y₅ is 0.23 W, and z₅ is 0.91 W. A length of the waist-shaped hole is determined as 0.3 W to 0.45 W, and a width of the waist-shaped hole is determined as 0.02 W to 0.1 W, thereby forming the slot outlet control cross-section.

Taking the right slot in the forward direction of the train as an example, a specific embodiment is described below.

Embodiment 1

(1) A shape and a position of a slot inlet control cross-section are described as follows.

• • a. On a side of the nose tip of the train 73, coordinates of a center point O₁ is determined as (x₁, y₁, z₁), where x₁ is 0.13 W, y₁ is 0.27 W, and z₁ is 0.13 W.
  • b. In a yoz plane, the center point O₁ is taken as an ellipse center point, a major axis radius is determined as 0.16 W, and a minor axis radius is determined as 0.7 W, thereby forming a first ellipse.
  • c. From a perspective of the positive direction of the x-axis, the first ellipse is rotated clockwise around the x-axis with the center point O₁ by 10° to form a second ellipse.

The second ellipse is configured to control a shape of a slot inlet 3, and an elliptical plane where the second ellipse is located is the slot inlet control cross-section.

A method for controlling the shape of the slot inlet 3 is as follows. An intersection surface is formed by intersecting a cylindrical formed by the second ellipse along the x-axis with a surface of the body of the train 71, and the intersection surface is defined as a slot inlet intersection surface.

(2) A shape and a position of a first slot intermediate control cross-section sec1 are described as follows.

The second ellipse is translated and scaled down proportionally to form the first slot intermediate control cross-section sec1, including the following specific operations.

• • a. The second ellipse is translated to make the center point O₁ of the second ellipse translate from the coordinates (x₁, y₁, z₁) to coordinates (x₂, y₂, z₂), to obtain a translated second ellipse, where x₂=x₁+Δx₁, Δx₁ is 0.43 W, as a result, x₂ is 0.56 W; y₂ is 0.27 W; and z₂ is 0.13 W. Then a position of the coordinates (x₂, y₂, z₂) is marked as a center point O₂, and the translated second ellipse is taken as a third ellipse.
  • b. The third ellipse is scaled down proportionally with a scaling factor of 90% to obtain the first slot intermediate control-section sec1.

(3) A shape and a position of a second slot intermediate control cross-section sec2 are described as follows.

• • a. Coordinates of a center point O₃ is determined as (x₃, y₃, z₃), where x₃=x₁+Δx₂, Δx₂ is 1.43 W, as a result, x₃ is 1.56 W; y₃ is 0.35 W; and z₃ is 0.15 W.
  • b. In the yoz plane, the center point O₃ is taken as an ellipse center point, a major axis radius is determined as 0.14 W, and a minor axis radius is determined as 0.06 W, thereby forming a fourth ellipse.
  • c. From a perspective of a negative direction of the y-axis, the fourth ellipse is rotated clockwise around the y-axis with the center point O₃ by 30° to form the second slot intermediate control cross-section sec2.

(4) A shape and a position of a third slot intermediate control cross-section sec3 are described as follows.

• • a. Coordinates of a center point O₄ is determined as (x₄, y₄, z₄), where x₄=x₁+Δx₃, Δx₃ is 1.84 W, as a result, x₄ is 1.97 W; y₄ is 0.23 W; z₄=z₁+Δz₃, and Δz₃ is 0.26 W, as a result, z₄ is 0.39 W.
  • b. In an xoy plane, the center point O₄ is taken as an ellipse center point, a major axis radius is determined as 0.11 W, and a minor axis radius is determined as 0.05 W, thereby forming a fifth ellipse.
  • c. From the perspective of the positive direction of the x-axis, the fifth ellipse is rotated clockwise around the x-axis with the center point O₄ by 5° to form the third slot intermediate control cross-section sec3.

(5) A shape and a position of a slot outlet control cross-section are described as follows.

A slot outlet 4 is defined on a range where an included angle between a top plane of the train behind a front windshield 74 of the head of the train 72 and the xoy plane is less than 10°, with a cross-section shape of a waist-shaped hole. The waist-shaped hole is parallel to the xoy plane. Coordinates of a center point O₅ of the waist-shaped hole is (x₅, y₅, z₅), where x₅ is 2.08 W, y₅ is 0.23 W, and z₅ is 0.91 W. A length of the waist-shaped hole is determined as 0.36 W, and a width of the waist-shaped hole is determined as 0.05 W, thereby forming the slot control cross-section.

Aerodynamic analysis and calculation are performed on a train model without any slot (i.e., a baseline model) and a train model with the slot configurations of the embodiment 1 of the disclosure, and results are shown in Table 1.

In the Table 1, the train body drag coefficient refers to a drag coefficient inherent to the body of the train. The slot drag coefficient refers to a drag coefficient of the slots alone. The overall train drag coefficient is a sum of the train body drag coefficient and the slot drag coefficient. The lift coefficient refers to an overall lift coefficient of the train under the combined effect of the train and the slots (if the slots present).

As can be seen from the Table 1, when no slot is provided, both the train body drag coefficient and the overall train drag coefficient are 0.308, and the lift coefficient is 0.057. In contrast, when the slot configurations of the embodiment 1 of the disclosure are implemented, the train body drag coefficient remains almost unchanged at 0.308, while the slot drag coefficient is 0.033, resulting in an increase in the overall train drag coefficient to 0.341. Thus, the implementation of the slot configurations of the embodiment 1 of the disclosure leads to the increase in the overall train drag coefficient. Compared to the train without the slots, the lift coefficient is reduced when the slots are provided according to the disclosure.

Therefore, compared to not having the slots, the disclosure increases the overall train drag coefficient by providing the slots, which can shorten a braking distance of the train. The disclosure also reduces the lift coefficient, slightly increasing downward force of the train and thereby enhancing operational safety of the train.

Therefore, the slot device designed in the disclosure can significantly increase the drag of the train and effectively reduce the braking distance. A control method of the slot device of the disclosure is simple, and it represents an effective drag-control approach, meeting the need for short-distance braking during high-speed operation of the train.

The disclosure originates from the needs of engineering applications and, based on the aerodynamic principles, innovatively integrates the slots with train drag-control, proposing the slot device for the high-speed train drag-control, which is a pioneering innovation. Main innovative aspects of the slot device for the high-speed train drag-control provided by the disclosure include: a concept of applying the slot device to the body of the train and its structural form, including a composition of each slot and the layout of the slot inlet 3 and the slot outlet 4, and further including the shapes of the five control cross-sections and their positional relationships relative to the body of the train.

The above is only the specific embodiments of the disclosure. It should be pointed out that for those skilled in the art, several improvements and refinements can be made without departing from the principles of the disclosure, and these improvements and refinements should also be considered within the scope of protection of the disclosure.