A method for optimizing the aerodynamic lifting force of pantograph head

Abstract

The present invention discloses a method for optimizing the aerodynamic lift force of a pantograph head. The method involves installing an airflow regulating convex plate on the carbon slide plate of the pantograph head to improve the flow field structure, thereby creating a pressure difference between the upper and lower sides of the carbon slide plate and thereby increasing the average aerodynamic lift force of the pantograph head. By installing the airflow regulating convex plate on the carbon slide plate of the pantograph head, the present invention improves the flow field structure and increases the average aerodynamic lift force of the pantograph head. This not only helps improve the pantograph-catenary tracking performance, meeting the pantograph-catenary contact force requirements of higher-speed trains and improving the current-collecting quality of the pantograph, but also, because the target value of the total pantograph lift force is fixed at the same speed, it can reduce the workload of the pantograph airbag, extend its service life, reduce the frequency of failures, and ensure safe and stable train operation.

Description

Technical Field

[0001] The present invention relates to the field of rail transit technology, and in particular to a method for optimizing the aerodynamic lifting force of a pantograph head. Background Art

[0002] As a vital link connecting cities, high-speed rail has become a primary mode of transportation for passengers. To meet people's demand for high-speed travel, my country has launched a research and development program for even higher-speed trains, with a designed speed of 400 kilometers per hour.

[0003] The pantograph, located atop the train, draws current from the catenary to power the train. The target pantograph-catenary contact force is positively correlated with the train's operating speed, with higher-speed trains placing a correspondingly higher demand. Excessive pantograph lifting force can lead to unstable pantograph power supply, arcing, and even, in severe cases, power outages.

[0004] The pantograph's lifting force is composed of both pneumatic lifting force and airbag force. The pneumatic lifting force directly impacts the quality of pantograph-catenary contact. At higher operating speeds, if the pantograph's aerodynamic performance is not optimized, the airbag will be subjected to a greater workload, shortening its service life and potentially increasing the frequency of failures. Therefore, excellent pantograph aerodynamic performance is crucial to the stability and safety of train operations. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for optimizing the aerodynamic lifting force of the pantograph head, which can improve the average aerodynamic lifting force of the pantograph head, thereby meeting the requirements of higher-speed trains for the pantograph-catenary contact force.

[0006] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0007] A method for optimizing the aerodynamic lifting force of a pantograph bow head is provided, wherein an airflow regulating convex plate is added to the carbon slide plate of the pantograph bow head to improve the flow field structure so as to form a pressure difference between the upper and lower sides of the carbon slide plate and thereby increase the average value of the aerodynamic lifting force of the bow head.

[0008] Preferably, the airflow regulating convex plate is arranged at the bottom of the carbon skateboard. The airflow regulating convex plate reduces the vortex intensity on the lower side of the carbon skateboard, converts large-scale vortices into small-scale vortices, improves the pressure environment on the lower side of the carbon skateboard, reduces the negative pressure intensity on the lower side of the carbon skateboard, and thereby increases the average aerodynamic lifting force of the bow head.

[0009] Preferably, the airflow regulating convex plate includes a convex plate body which is arranged along the length direction of the carbon slide plate and protrudes downward from the bottom of the carbon slide plate.

[0010] Preferably, the upper part of the convex plate body is embedded in the main structure of the carbon slide; the airflow regulating convex plate also includes a telescopic cylinder arranged in the main structure of the carbon slide and connected to the convex plate body, which is used to drive the convex plate body to move according to the actual train speed to change the height of the convex plate body protruding downward from the carbon slide.

[0011] Preferably, the airflow regulating convex plate is an embedded retractable structure, and also includes a telescopic cylinder arranged in the main structure of the carbon slide and connected to the convex plate body, which is used to drive the convex plate body to move according to the actual train speed so as to protrude the convex plate body downward from the bottom of the carbon slide and change the height of the convex plate body protruding downward from the carbon slide.

[0012] Preferably, the number of airflow regulating convex plates is adjusted according to the train design conditions, including but not limited to the running speed and the running environment.

[0013] Preferably, a plurality of airflow regulating convex plates are provided, and the plurality of airflow regulating convex plates are arranged symmetrically or asymmetrically along the center line of the carbon slide plate to achieve different lift-increasing effects of the pantograph in different operating directions.

[0014] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is as follows.

[0015] The present invention provides an airflow regulating convex plate at the bottom of the carbon slide plate of the pantograph bow head to improve the flow field structure and increase the average value of the aerodynamic lifting force of the bow head. This not only helps to improve the pantograph-net followability, but also meets the requirements of higher-speed trains for the pantograph-net contact force and improves the current collection quality of the pantograph. Moreover, because the target value of the total lifting force of the pantograph head is fixed at the same speed, the workload of the pantograph airbag can be reduced, its service life can be extended, the frequency of failures can be reduced, and the safe and smooth operation of the train can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of an existing pantograph;

[0017] Figure 2 for Figure 1 AA view of the existing pantograph equipped with the airflow adjustment convex plate of the present invention;

[0018] Figure 3 This is a diagram of the flow field optimization mechanism of the present invention;

[0019] Figure 4 The aerodynamic lift time history curves of the original carbon slide and the carbon slide equipped with an airflow adjustment convex plate (the height of the convex plate body protruding downward from the carbon slide is adjusted to 3 mm) according to Example 1 of the present invention;

[0020] Figure 5The aerodynamic lift time history curves of the original carbon slide and the carbon slide equipped with an airflow adjustment convex plate (the height of the convex plate body protruding downward from the carbon slide is adjusted to 8 mm) according to Example 2 of the present invention;

[0021] Figure 6 The aerodynamic lift results of the pantograph head obtained by closed-loop operation of the pantograph at different train speeds using the third embodiment of the present invention, with the original carbon slide and the carbon slide equipped with an airflow adjustment convex plate (the height of the convex plate protruding downward from the carbon slide was adjusted to 3 mm) were obtained in an aviation wind tunnel.

[0022] Figure 7 The results of the comparison of the standard values ​​of the lifting force and contact force of the carbon slide bow head of the pantograph under different train speeds in Example 4 of the present invention are as follows: the original carbon slide and the airflow adjustment convex plate installed on the pantograph (the height of the convex plate body protruding downward from the carbon slide is adjusted to 3 mm).

[0023] Including: 1. Carbon slide plate, 2. Airflow adjustment convex plate, 21. Convex plate body. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] A method for optimizing the aerodynamic lift force of a pantograph bow head is based on the fact that when the airflow passes through the carbon slide of the pantograph bow head at high speed, the flow separation occurs on the upper and lower sides of the carbon slide, forming large-scale vortices. Under the action of the separation vortex, low-pressure and low-speed areas are formed on the upper and lower sides of the carbon slide. Figures 1 to 2 As shown, the specific method is to install an airflow regulating convex plate 2 at the carbon slide plate 1 of the pantograph bow head, and improve the flow field structure through the airflow regulating convex plate 2, so that a pressure difference is formed on the upper and lower sides of the carbon slide plate 1, thereby achieving the purpose of increasing the average value of the aerodynamic lifting force of the bow head.

[0026] Specifically, the airflow regulating convex plate 2 is arranged at the bottom of the carbon slide 1, and the airflow regulating convex plate 2 includes a convex plate body 21, which is arranged along the length direction of the carbon slide 1 and protrudes downward from the bottom of the carbon slide 1. Figure 3 As shown in the figure, under the influence of the convex plate body 21, the vortex intensity on the lower side of the carbon slide 1 is reduced, and the large-scale vortex is transformed into a small-scale vortex, which significantly improves the pressure environment on the lower side of the carbon slide 1 and reduces the negative pressure intensity on the lower side of the carbon slide 1, thereby achieving the purpose of increasing the average aerodynamic lift force of the bow head.

[0027] Airflow adjustment convex plate design scheme 1

[0028] The upper portion of the cam body 21 is embedded in the main structure of the carbon slide 1. The airflow regulating cam 2 also includes a telescopic cylinder, which is installed in the main structure of the carbon slide 1 and connected to the cam body 21. The telescopic cylinder is used to drive the cam body 21 according to the actual train speed, thereby adjusting the position of the cam body 21 and changing the height of the cam body 21 protruding downward from the carbon slide 1 to achieve different degrees of lift-enhancing effect. In this solution, because only the upper portion of the cam body 21 is embedded in the main structure of the carbon slide 1, the cam body 21 cannot be fully retracted into the carbon slide 1. However, this solution expands the adjustment range of the airflow regulating cam 2, making it more suitable for use on higher-speed trains.

[0029] Airflow adjustment convex plate design scheme 2

[0030] The airflow-regulating cam 2 is an embedded, retractable structure that includes a telescopic cylinder, mounted within the main structure of the carbon slide 1 and connected to the cam body 21. This cylinder drives the cam body 21 according to the actual train speed, adjusting its position. This allows the cam body 21 to protrude downward from the bottom of the carbon slide 1 and adjusts the height at which it protrudes from the slide, achieving varying degrees of lift. In this solution, the cam body 21 can be fully retracted into the carbon slide 1, suitable for use on low-speed trains.

[0031] The number of airflow regulating convex plates 2 can be adjusted according to the train's operating speed, operating environment, or other design conditions. The airflow regulating convex plates 2 can be arranged symmetrically or asymmetrically along the centerline of the carbon slide plate 1 to achieve different lift-enhancing effects in different pantograph operating directions. Example 1

[0032] like Figure 4 As shown in Figure 1, based on the fluid computation software Fluent, this example provides numerical simulation results of the aerodynamic lift force of an original carbon slide (i.e., without the airflow control cam) and an improved carbon slide (with the cam body adjusted to a 3 mm downward protrusion). With the airflow control cam installed, the average aerodynamic lift force of the carbon slide increased from 102.9 N to 128.4 N, a 24.8% increase. Therefore, it can be concluded that the airflow control cam improves the flow field structure around the carbon slide, increasing its average aerodynamic lift force. Example 2

[0033] like Figure 5 As shown in Figure 2, this example provides numerical simulation results for the aerodynamic lift of an original carbon slide and an improved carbon slide (with the raised plate body adjusted to 8 mm downward from the carbon slide). After installing the airflow-regulating raised plate, the average aerodynamic lift of the carbon slide increased from 102.9 N to 148.9 N, a 44.7% increase. Therefore, it can be concluded that varying degrees of lift enhancement can be achieved by adjusting the raised plate body height. Example 3

[0034] The accuracy of numerical calculations is easily affected by many factors, and due to the limitation of computing resources, the first and second embodiments only provide numerical simulation results of 0.2 s. Figure 6 As shown in the figure, this embodiment provides the total pantograph lift force (static contact force of 80 N) obtained from closed-loop operation of a certain type of pantograph at different train speeds, using both the original carbon slide and a carbon slide equipped with an airflow-regulating cam (the cam body was adjusted to protrude 3 mm downward from the carbon slide). The total pantograph lift force increased at all train speeds, particularly at high train speeds (320 km / h), where it increased from 107.4 N to 223.6 N, a 108.2% increase. Example 4

[0035] like Figure 7 As shown in Figure 2, this embodiment provides a comparison of the standard values ​​of the carbon slide head lifting force and contact force for pantographs with the original carbon slide and with an airflow adjustment cam (the height of the cam body protruding downward from the carbon slide is adjusted to 3 mm) at different train speeds. The fitting formula for the pantograph head lifting force when the cam body protrudes downward from the carbon slide by 3 mm is:

[0036]

[0037] in, y It is the lifting force of the bow head; x It is the height of the convex plate body protruding downward from the carbon slide plate.

[0038] and Figure 7 R in 2 Represents how well the fitting curve (lift fitting formula) fits the data points. The closer it is to 1, the better.

[0039] The target value of the pantograph-catenary contact force is obtained by consulting the data:

[0040]

[0041] According to the above embodiments, the increment of the bow head lifting force is directly proportional to the height of the convex plate body of the airflow regulating convex plate. When the train speed is 220 km / h and below, the lifting force of the original carbon skateboard installed on the pantograph is well matched with the contact force target value. It is recommended to fully retract the convex plate body and appropriately reduce the airbag pressure; when the train speed is higher than 220 km / h, the lifting force of the original carbon skateboard installed on the pantograph can no longer meet the contact force target value. When the train speed is between 220 km / h and 400 km / h, it is recommended to adjust the convex plate body height of the airflow adjustment convex plate to 1-3 mm and adjust the airbag pressure appropriately according to the contact force monitoring value; when the train speed is between 400 km / h and 450 km / h, it is recommended to adjust the convex plate body height of the airflow adjustment convex plate to 3 mm, the lifting force of the pantograph is well matched with the contact force target value, and the airbag pressure can be appropriately reduced; when the train speed exceeds 450 km / h or encounters extremely harsh environments, it is recommended to appropriately increase the convex plate body height of the airflow adjustment convex plate to ensure stable airflow collection by the train.

[0042] When in use, the present invention can be widely applied to pantograph systems of high-speed EMUs and other rail transportation vehicles.

Claims

1. A method for optimizing the aerodynamic lifting force of a pantograph head, characterized by: The method comprises installing an airflow regulating convex plate (2) on a carbon slide plate (1) of a pantograph bow head for improving the flow field structure so as to form a pressure difference between the upper and lower sides of the carbon slide plate (1) to increase the average value of the aerodynamic lifting force of the bow head; The airflow regulating convex plate (2) is arranged at the bottom of the carbon slide plate (1). The airflow regulating convex plate (2) reduces the vortex intensity on the lower side of the carbon slide plate (1), converting large-scale vortices into small-scale vortices, thereby improving the pressure environment on the lower side of the carbon slide plate (1), reducing the negative pressure intensity on the lower side of the carbon slide plate (1), and thereby increasing the average value of the aerodynamic lifting force of the bow head; The airflow regulating convex plate (2) comprises a convex plate body (21) arranged along the length direction of the carbon slide plate (1) and protruding downward from the bottom of the carbon slide plate (1) and capable of changing the downward protruding height. When the train speed is 220 km / h or below, the convex plate body (21) is fully retracted and the airbag pressure is appropriately reduced; when the train speed is within the range of 220 km / h to 400 km / h, the height of the convex plate body (21) is adjusted to 1-3 mm, and the airbag pressure is appropriately adjusted according to the contact force monitoring value; when the train speed is within the range of 400 km / h to 450 km / h, the height of the convex plate body (21) is adjusted to 3 mm, and the airbag pressure can be appropriately reduced; when the train speed exceeds 450 km / h or encounters an extremely harsh environment, the height of the convex plate body (21) is increased; The bow head lifting force fitting formula is as follows: in, y It is the lifting force of the bow head; x It is the height of the convex plate body protruding downward from the carbon slide plate.

2. The method for optimizing the aerodynamic lifting force of a pantograph head according to claim 1, characterized in that: The upper portion of the convex plate body (21) is embedded in the main structure of the carbon slide (1); the airflow regulating convex plate (2) further comprises a telescopic cylinder arranged in the main structure of the carbon slide (1) and connected to the convex plate body (21), and used to drive the convex plate body (21) to move according to the actual train speed so as to change the height of the convex plate body (21) protruding downward from the carbon slide (1).

3. The method for optimizing the aerodynamic lifting force of a pantograph head according to claim 1, characterized in that: The airflow regulating convex plate (2) is an embedded retractable structure, and further comprises a retractable cylinder arranged in the main structure of the carbon slide (1) and connected to the convex plate body (21), and used to drive the convex plate body (21) to move according to the actual train speed so as to protrude the convex plate body (21) downward from the bottom of the carbon slide (1) and change the height of the convex plate body (21) protruding downward from the carbon slide (1).

4. The method for optimizing the aerodynamic lifting force of a pantograph head according to claim 1, characterized in that: The number of airflow regulating convex plates (2) is adjusted according to the train design conditions, including but not limited to the running speed and the running environment.

5. The method for optimizing the aerodynamic lifting force of a pantograph head according to claim 1, characterized in that: A plurality of airflow regulating convex plates (2) are provided, and the plurality of airflow regulating convex plates (2) are symmetrically or asymmetrically arranged along the center line of the carbon slide plate (1) to achieve different lift-increasing effects when the pantograph is in different operating directions.

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