Resistance reduction design method for regional key configuration of bogie

Abstract

The invention provides a resistance reduction design method for a bogie area key configuration, the bogie area key configuration comprises a bogie cabin apron board configuration, a bogie cabin front and rear end configuration, a bogie bottom plate configuration and a bogie bottom plate combination configuration, and the method comprises the following steps: designing the bogie cabin apron board configuration; the bogie cabin apron board structure with the best whole vehicle drag reduction effect is obtained; designing front and rear end structures of the bogie cabin to obtain the front and rear end structures of the bogie cabin with the best whole vehicle drag reduction effect; a bogie bottom plate structure is designed, and a bogie cabin bottom plate structure with the best whole vehicle drag reduction effect is obtained; and a bogie bottom plate combination configuration scheme is designed, and the scheme that the whole vehicle drag reduction effect meets the requirement and the comprehensive condition is optimal is obtained. Compared with a single structure in the prior art, the damping device is more reasonable and reliable, and the damping effect on the whole vehicle is better.

Description

Technical Field

[0001] The invention relates to the technical field of drag reduction in a bogie region, and in particular to a drag reduction design method for a key configuration in a bogie region. Background Art

[0002] Bogies and wheels are important structures at the bottom of trains. Their complex structures have a great impact on the aerodynamic performance of trains during travel. The aerodynamic drag in the bogie area accounts for more than 20% of the total vehicle drag and is an important component of the train's running resistance. Therefore, it is very important to study the drag reduction mechanism and configuration optimization design of the bogie area of ​​trains, especially high-speed trains.

[0003] For the benchmark train model, for the convenience of expression, the 16 bogies (8 carriages) from the front to the rear are represented by bogies 1-16 respectively. At the nose tip of the leading car, due to the impact of the front flow, a local strong positive pressure distribution is presented, and from the nose tip to the rear, due to the increase in surface curvature, a strong negative pressure distribution is presented. This development pattern also affects the bogie 1 area, resulting in a negative pressure distribution inside the bogie compartment. From the bogie 1 area to the rear, the negative pressure gradually weakens. From the middle of the leading car to the middle of the rear car, due to the lack of obvious curvature change on the car body surface, the pressure distribution is close to 0, resulting in no obvious difference in the pressure distribution pattern of bogies 2-15. In the area close to the rear of the train, due to the increase in surface curvature again, the car body surface presents a negative pressure pattern, which affects the pressure properties in the bogie compartment, resulting in a more obvious negative pressure distribution on the surface of bogie 16.

[0004] At the same time, for all bogie areas, high turbulent kinetic energy is mainly concentrated at the height of the intersection between the wheelset and the bottom, showing a strip distribution. It is most obvious inside the bogie 1 at the front end of the lead car, showing a high-energy distribution. This is related to the interference of the complex structure of the bogie on the flow, that is, the flow field under the car is smooth and the speed is relatively high, and the interference effect of the bogie is the strongest; after the air enters the bogie compartment, the flow velocity weakens and the turbulent kinetic energy intensity is also significantly reduced.

[0005] For the bogie area, the key configurations include the bogie cabin skirt, the front and rear end structures of the bogie cabin, the bogie floor form and the combined configuration. Therefore, the drag reduction mechanism can be analyzed by analyzing the bogie pressure distribution, flow field distribution, aerodynamic changes of each vehicle and other laws. Although there are configurations for drag reduction in the bogie area in the prior art, no systematic drag reduction design solution has been found yet. Summary of the invention

[0006] The purpose of the present invention is to provide a more systematic bogie area drag reduction solution that comprehensively considers multiple aspects in view of the shortcomings of the above-mentioned background technology.

[0007] In order to achieve the above object, the present invention provides a method for designing drag reduction of key configurations in the bogie region, wherein the key configurations in the bogie region include a bogie cabin skirt configuration, a bogie cabin front and rear end configuration, a bogie floor configuration, and a bogie floor combination configuration, and the method comprises the following steps:

[0008] S1, design the bogie cabin skirt configuration to obtain the bogie cabin skirt configuration with the best vehicle drag reduction effect;

[0009] S2, based on the design of S1, designs the front and rear end configurations of the bogie compartment to obtain the front and rear end configurations of the bogie compartment with the best drag reduction effect for the whole vehicle;

[0010] S3, based on the design of S2, designs the bogie floor configuration to obtain the bogie cabin floor configuration with the best drag reduction effect for the whole vehicle;

[0011] S4, based on the design of S3, designs the combination configuration of the bogie bottom plate to obtain a vehicle drag reduction effect that meets the requirements and takes into account the actual situation.

[0012] Furthermore, the bogie cabin skirt configuration in S1 includes a reference configuration, an uneven skirt configuration, a flush skirt configuration, and an inward-retracted skirt configuration.

[0013] Furthermore, the inward-retracted skirt configuration in S1 has the best drag reduction effect on the entire vehicle, and each carriage also has the best drag reduction effect when the inward-retracted skirt configuration is adopted.

[0014] Furthermore, the front and rear end configurations of the bogie cabin in S2 include a single-sided straight wall configuration, an inclined wall small arc transition configuration, an inclined wall large arc transition configuration, a straight wall straight line transition configuration, and an arc wall arc transition configuration.

[0015] Furthermore, the front and rear end configurations of the bogie compartment in S2 adopt an inclined wall small arc transition configuration and / or a straight wall straight line transition configuration.

[0016] Furthermore, carriage 3 in S2 adopts a straight-wall straight-line transition configuration, and other carriages adopt an inclined-wall small-arc transition configuration.

[0017] Furthermore, the bogie bottom plate configuration in S3 includes a sunken split bottom plate configuration, a flush split bottom plate configuration and a flush integrated bottom plate configuration.

[0018] Furthermore, the S3 adopts a flush integrated floor configuration, which has the best drag reduction effect for the entire vehicle.

[0019] Furthermore, the combined configuration schemes of the bogie bottom plate in S4 include skirt plate covering, head and tail covering, trailer covering, and full vehicle covering;

[0020] In the skirt covering, no car is provided with a bogie bottom plate configuration; in the head and tail covering, car 1 and car 8 are provided with a bogie bottom plate configuration; in the trailer covering, car 1, car 3, car 6, and car 8 are provided with a bogie bottom plate configuration; in the full car covering, all cars are provided with a bogie bottom plate configuration;

[0021] The bogie bottom plate configuration is a flush integrated bottom plate configuration.

[0022] Furthermore, head and tail wrapping or trailer wrapping is adopted in S4.

[0023] The above scheme of the present invention has the following beneficial effects:

[0024] The drag reduction design method for key configurations of the bogie region provided by the present invention comprehensively considers the effects of four key configurations and various different configurations in the bogie region, performs systematic configuration for different carriages, analyzes the drag reduction mechanism, and obtains an optimized drag reduction design scheme with reference to actual conditions (or other aspects). Compared with the single structure in the prior art, it is more reasonable and reliable, and has a better drag reduction effect on the whole vehicle.

[0025] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the bogie area designed for the present invention;

[0027] Figure 2 Schematic diagram of bogie cabin skirt plate configuration of the present invention, wherein (a) is a reference configuration, (b) is an uneven skirt plate configuration, (c) is a flush skirt plate configuration, and (d) is an inward-retracted skirt plate configuration;

[0028] Figure 3 1 are typical bogie area pressure distribution diagrams under different bogie cabin skirt plate configurations of the present invention, wherein (a) is bogie 1, (b) is bogie 2, (c) is bogie 15, and (d) is bogie 16;

[0029] Figure 4 2 are flow velocity distribution diagrams of the central cross section of a typical bogie region under different bogie cabin skirt plate configurations of the present invention, wherein (a) is bogie 1, (b) is bogie 2, (c) is bogie 15, and (d) is bogie 16;

[0030] Figure 5 Schematic diagram of the front and rear end configurations of the bogie cabin of the present invention, wherein (a) is a single-side straight wall configuration, (b) is an inclined wall small arc transition configuration, (c) is an inclined wall large arc transition configuration, (d) is a straight wall straight line transition configuration, and (e) is an inclined wall large arc transition configuration;

[0031] Figure 61 is a typical bogie area pressure distribution diagram under different bogie compartment front and rear end configurations of the present invention, wherein (a) is bogie 1, (b) is bogie 2, (c) is bogie 15, and (d) is bogie 16;

[0032] Figure 7 2 are flow velocity distribution diagrams of the central cross section of a typical bogie region under different bogie compartment front and rear end configurations of the present invention, wherein (a) is bogie 1, (b) is bogie 2, (c) is bogie 15, and (d) is bogie 16;

[0033] Figure 8 Schematic diagram of the bogie bottom plate configuration of the present invention, wherein (a) is a sunken split configuration, (b) is a flush split configuration, and (c) is a flush integrated configuration;

[0034] Fig. 9 1 are typical bogie area pressure distribution diagrams under different bogie bottom plate configurations of the present invention, wherein (a) is bogie 1, (b) is bogie 2, (c) is bogie 15, and (d) is bogie 16;

[0035] Fig.10 3 and 4, which are flow velocity distribution diagrams of the central section of a typical bogie area under different bogie bottom plate configurations of the present invention, wherein (a) is bogie 1, (b) is bogie 2, (c) is bogie 15, and (d) is bogie 16. DETAILED DESCRIPTION

[0036] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0037] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein may be implemented independently of any other aspect, and two or more of these aspects may be combined in various ways. For example, any number of aspects described herein may be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein may be used to implement this device and / or practice this method.

[0038] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure, and the illustrations only show the components related to the present disclosure rather than the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in actual implementation may be changed at will, and the component layout type may also be more complicated. In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the aspects described can be practiced without these specific details.

[0039] The embodiment of the present invention provides a method for designing drag reduction of key configurations in the bogie region, wherein the corresponding key configurations in the bogie region include four categories: bogie cabin skirt configuration, bogie cabin front and rear end configuration, bogie floor configuration, and bogie floor combination configuration. Figure 1 Shown is a schematic diagram of a bogie region.

[0040] For the bogie cabin skirt, it mainly includes Figure 2 The four configurations shown are the reference configuration (no skirt), the non-flat skirt configuration (inward and outward convex), the flat skirt configuration, and the inward skirt configuration. Considering that the cross-sectional curvature of the middle car has a small change and the flow difference is small, this embodiment focuses on analyzing the bogies 1 and 2 and bogies 15 and 16 of car 1 (head car) and car 8 (tail car). The pressure distribution of the bogie area of ​​the four configurations is shown in Figure 1. Figure 3As shown. For the bogie 1 area, due to the significant influence of the negative pressure distribution of the head car, changing the bogie cabin skirt configuration did not bring about a significant change in the pressure distribution; in the bogie 2 area, the uneven skirt configuration and the flush skirt configuration brought about a slight decrease in the pressure amplitude of the rear wheelset, which is related to the flow diversion effect of the skirt; for the bogie 15 area of ​​the tail car, the flush skirt configuration and the retracted skirt configuration enhanced the amplitude of the pressure distribution, indicating that the flush skirt configuration and the retracted skirt configuration have a good smoothing effect on the flow under the car, which increases the speed of the upstream flow at the bottom, resulting in a more intense flow entering the bogie cabin and a more significant pressure distribution in the bogie area; in the bogie 16 area of ​​the tail car, due to the influence of the negative pressure distribution caused by the change in curvature, the effect of changing the skirt configuration on the change in pressure distribution is limited, and only the pressure amplitude increases under the retracted skirt configuration.

[0041] At the same time, for the four configurations of the bogie cabin skirt, the flow velocity distribution in the center flow direction of the bogie area is as follows: Figure 4 As shown. In the bogie 1 area, changing the skirt configuration did not significantly change the flow velocity distribution in the bogie cabin; in the bogie 2 area, the installation of the skirt effectively increased the airflow velocity under the car, because the skirt's guiding effect achieved smooth flow, and this mechanism of action made all subsequent bogie areas present similar undercarriage airflow acceleration effects; in the bogie 16 area, the installation of the skirt weakened the flow velocity amplitude in the cabin space, because the skirt's guiding effect reduced the air mass flow entering the bogie cabin. Among them, the undercarriage flow velocity in the bogie 15 and 16 areas was further reduced, which was related to the flow blockage caused by the turbulence effect under the car.

[0042] Based on the above preliminary analysis, it is found that different bogie cabin skirt configurations have different effects on the air flow in the bogie area. Therefore, the effect of different bogie cabin skirt configurations on train drag reduction is further analyzed. The aerodynamic results of each car before and after the optimization of the bogie cabin skirt configuration are shown in Table 1. Analysis and comparison of the results in Table 1 show that compared with the condition without skirts, adding skirts has different degrees of drag reduction: the drag reduction rate of the whole vehicle with uneven skirt configuration reaches 6.69%, and the drag reduction rate of the leading car is the highest, which can reach 1.51%; the drag reduction rate of the whole vehicle with flat skirt configuration reaches 5.49%, and the drag reduction rate of the tail car is the highest, which can reach 1.54%; the drag reduction effect of adding inward skirt configuration is the most obvious, and the drag reduction rate of the whole vehicle reaches 8.40%, and the drag reduction of the leading car is obvious, which is 2.01%. It can be seen that the inward skirt configuration has the best drag reduction effect, and the drag reduction effect is also better when each car adopts this configuration.

[0043] Table 1 Drag coefficient and drag reduction rate of each car under different bogie cabin skirt configurations

[0044]

[0045] In this embodiment, the front and rear end configurations of the bogie compartment include: Figure 5 The five configurations shown (all bogie cabin skirt configurations are inward-retracted skirt configurations) are a single-sided straight wall configuration, an inclined wall small arc transition configuration, an inclined wall large arc transition configuration, a straight wall straight line transition configuration, and an arc wall arc transition configuration.

[0046] The pressure distribution of the bogie 1 and 2 areas of the leading car and the bogie 15 and 16 areas of the trailing car under the five bogie compartment front and rear end configurations is as follows: Figure 6 As shown. The bogie 1 area is affected by the negative pressure distribution of the head car streamline. The pressure distribution is similar under different bogie compartment front and rear end configurations, and the negative pressure of the bogie compartment is dominant. In the bogie 2 area, the pressure distribution brought by the straight wall straight line transition is similar to the original single-side straight wall configuration. The inclined wall small arc transition and the inclined wall large arc transition configuration increase the opening area in front of the bogie compartment, and more incoming flow enters the compartment, resulting in a greater impact on the front facade of the bogie, resulting in a significant increase in pressure amplitude. The arc wall arc transition configuration further enhances the flow diversion effect on the incoming flow, and the airflow impact is strong, resulting in a prominent positive pressure at the front of the bogie. The differences brought by the front and rear end configurations of each bogie compartment in the bogie 15 area are reduced. In the bogie 16 area, the arc wall arc transition configuration induces airflow impact on the bogie due to its diversion effect, resulting in a significant increase in the positive pressure on its front surface. This mechanism will increase the local pressure difference resistance.

[0047] At the same time, the flow velocity distribution of the center flow section of the bogie area under the five configurations is as follows: Figure 7 As shown in the figure. In the bogie 1 area, the configuration change did not significantly change the flow velocity distribution in the bogie cabin; in the bogie 2 area, the large arc transition configuration of the inclined wall effectively increased the air velocity in the cabin, because the larger angle of the front end caused more air to enter the bogie cabin, and this mechanism of action was also clearly reflected in the arc transition configuration of the arc wall; due to the blocking effect of the flow under the car, the flow velocity under the car in the tail car bogie 15 and 16 areas was further reduced, making the difference in the influence of the front and rear end configurations of the bogie cabin on the flow velocity in the tail car part relatively small.

[0048] The aerodynamic results of the optimization of the front and rear end configurations of the bogie cabin are shown in Table 2. It can be seen from the results in Table 2 that the optimization effects are different compared with the original scheme (single-side straight wall configuration). The inclined wall small arc transition configuration and the straight wall straight line transition configuration are drag reduction, while the inclined wall large arc transition configuration and the arc wall arc transition configuration are drag increase. The front and rear end configurations of the bogie cabin also have different effects on each car: for the scheme with drag reduction effect, that is, the inclined wall small arc transition configuration and the straight wall straight line transition configuration, the drag reduction effect mainly comes from car 1, car 3 and car 6, and car 3 is the most significant, reaching 0.79%, but car 4 and car 5 also increase drag more, offsetting part of the drag reduction effect; for the scheme with drag increase effect, that is, the inclined wall large arc transition configuration and the arc wall arc transition configuration, cars 4 to 7 all increase drag significantly, especially for the latter, the head and tail cars increase drag significantly. It is understandable that an overly smooth or overly open end design is not conducive to drag reduction in the bogie area, and may even lead to a serious drag increase effect. Therefore, the front and rear end configurations of the bogie cabin preferably adopt an inclined wall with a small arc transition configuration, or a straight wall with a straight line transition configuration. Considering the convenience of layout, each car adopts the same configuration to achieve a better effect of reducing the impact of airflow on the bogie and the bogie cabin wall, and does not bring additional aerodynamic resistance. Of course, it is also possible to consider mixing two or more configurations to further improve the drag reduction rate. For example, car 3 adopts a straight wall and a straight line transition configuration, and other cars adopt an inclined wall with a small arc transition configuration; or cars 4, 5, and 7 adopt a single-sided straight wall configuration, and the others are consistent with the above.

[0049] Table 2 Drag coefficient and drag reduction rate of each car under different bogie cabin front and rear end configurations

[0050]

[0051]

[0052] In this embodiment, the bogie bottom plate configuration includes: Figure 8 The three configurations shown (bogie cabin skirt configurations are all inward-retracted skirt configurations, and the front and rear end configurations of the bogie cabin are inclined wall small arc transition configurations) are respectively a sunken split floor configuration, a flush split floor configuration, and a flush integrated floor configuration. Taking into account the small curve radius of the line in actual train use, the design of the bogie floor must ensure that there is enough space for movement between the floor edge and the wheelset or car body. The pressure distribution in the lead car bogie 1, 2 area and the tail car bogie 15, 16 area under the three bogie floor configurations is shown in the figure below. Fig. 9As shown. From the pressure distribution, it can be seen that the pressure amplitude in the bogie 1 area of ​​the sunken split bottom plate configuration is higher than that of the other two configurations. This may be related to the pressure increase caused by the high-speed airflow at the bottom entering the bogie compartment and impacting the surface of the bogie structure. Due to the different positions of the plate openings, there is pressure concentration in the local area of ​​the bogie, and the pressure distribution pattern is different. This difference in the position of the bottom plate openings also brings similar differences in the bogie 15 and 16 areas of the tail car, but due to the existence of the bottom plate, the overall pressure distribution pattern of the bogie area is less different.

[0053] The flow velocity distribution of the center flow section of the bogie area with different bogie bottom plate configurations is as follows: Fig.10 As shown. For the bogie 1 area, the sinking split floor configuration brings a higher flow velocity in the bogie area than the other two forms, indicating that the airflow impact is more intense, which also explains why the pressure in the bogie area in the sinking split floor is higher than that in other forms; from the bogie 2 area, it can be seen that the airflow in the bogie cabin mainly enters from the rear side of the bogie cabin. After setting the integrated bogie floor configuration, the flow field structure in the bogie cabin changes, and the floor effectively blocks the airflow entering the bogie cabin. The speed amplitude in the bogie cabin is significantly lower than that of the sinking split floor configuration, among which the high-speed area behind the bogie 2 area is greatly reduced; for the tail car, the sinking split floor configuration will still increase the speed of the airflow entering the cabin in the bogie 15 area, which is not conducive to drag reduction.

[0054] The aerodynamic results of the optimized bogie floor configuration are shown in Table 3. Analysis and comparison of the results in Table 3 show that, compared with the baseline working condition (only the inward skirt configuration and the inclined wall small arc transition configuration are set), the vehicle drag increases by 2.18% after the sunken split floor configuration is adopted. Obviously, the drag of the excessively sunken floor itself is too large, which worsens the drag reduction effect; the flush split floor configuration can bring a further drag reduction of 3.47% for the whole vehicle, among which the drag reduction of the leading car is the best, which can be increased by 2.43%; after adopting the flush integrated floor configuration, the drag reduction of the whole vehicle can be greatly improved by 5.60%, and the drag reduction effect mainly comes from the contribution of the leading car and the tail car, and the drag reduction rates of the single car are increased by 2.74% and 1.60% respectively, but it is also noted that the drag reduction rate of car 2 has deteriorated.

[0055] Table 3 Drag coefficient and drag reduction rate of each carriage with different bogie floor configurations

[0056]

[0057] According to the above analysis, the bogie configuration of car 1, i.e. the head car, has the most obvious influence on the resistance. Therefore, for the bogie floor combination configuration, different schemes all include car 1, as shown in Table 4, and all adopt a flush integrated floor configuration. Because the floor setting of car 1 remains unchanged, the analysis focuses on the bogie 5 area of ​​car 3, the bogie 11 area of ​​car 6, and the bogie 16 area of ​​car 8.

[0058] Table 4 Combination configuration schemes of different carriage bogie bottom plates

[0059]

[0060] The aerodynamic results of different car bogie floor combinations are compared and analyzed, and the aerodynamic results of each solution are shown in Table 5. As can be seen from Table 5, compared with the skirt-only covering, the head and tail, trailer and full car covering with a flush integrated floor configuration can improve the drag reduction effect of the whole car by 5.60%, 7.08% and 10.55% respectively, and the effect is very obvious, and the contribution of the head car is the most outstanding. Compared with the original model (data in Table 1 without skirts), the drag reduction effect of the whole car covered by the full car even reaches 16.53%. On the basis of the head and tail covering, the trailer covering can further improve the drag reduction effect of car 3 and car 6, but it also leads to a deterioration of the drag reduction effect of the rear car floor. For the full car floor covering, the drag reduction of all cars except the rear car is not less than 1%. However, it should be noted that this kind of floor covering setting will bring about problems such as structural safety and operation and maintenance while achieving drag reduction. Especially for the power car, the heat dissipation effect of the motor and brake pads in the bogie cabin will also be affected to a certain extent. Therefore, considering the influence of various factors, it is preferred to adopt the solution of head and tail covering or trailer covering.

[0061] Table 5 Drag coefficient and drag reduction rate of each carriage for different carriage bogie bottom plate combination configuration schemes

[0062]

[0063] To sum up, the drag reduction design method for key configurations in the bogie area provided in this embodiment takes into account four types of key configurations in the bogie area and various forms of replacement, carries out systematic configuration for different carriages, analyzes the drag reduction mechanism, and obtains a drag reduction design scheme based on actual conditions. Compared with the single structure in the prior art, it is more reasonable and reliable, and has a better effect on the drag reduction of the entire vehicle.

[0064] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for reducing drag of key configurations in a bogie region, characterized in that: The key configuration of the bogie area includes the bogie cabin skirt configuration, the front and rear end configurations of the bogie cabin, the bogie floor configuration, and the bogie floor combination configuration. The method comprises the following steps: S1, design the bogie cabin skirt configuration to obtain the bogie cabin skirt configuration with the best vehicle drag reduction effect; S2, based on the design of S1, designs the front and rear end configurations of the bogie compartment to obtain the front and rear end configurations of the bogie compartment with the best drag reduction effect for the whole vehicle; S3, based on the design of S2, designs the bogie floor configuration to obtain the bogie cabin floor configuration with the best drag reduction effect for the whole vehicle; S4, based on the design of S3, designs the combination configuration of the bogie bottom plate to obtain a vehicle drag reduction effect that meets the requirements and takes into account the actual situation.

2. A method for designing drag reduction of key configurations in a bogie region according to claim 1, characterized in that: The bogie cabin skirt configurations in S1 include the reference configuration, the uneven skirt configuration, the flush skirt configuration, and the inward-retracted skirt configuration.

3. A method for designing drag reduction of key configurations in a bogie region according to claim 2, characterized in that: The inward-retracted skirt configuration in S1 has the best drag reduction effect on the entire vehicle, and the drag reduction effect of each car is also the best when the inward-retracted skirt configuration is adopted.

4. A method for designing drag reduction of key configurations in a bogie region according to claim 3, characterized in that: The front and rear end configurations of the bogie cabin in S2 include a single-sided straight wall configuration, an inclined wall with a small arc transition configuration, an inclined wall with a large arc transition configuration, a straight wall with a straight line transition configuration, and an arc wall with an arc transition configuration.

5. A method for designing drag reduction of key configurations in a bogie region according to claim 4, characterized in that: The front and rear end configurations of the bogie compartment in S2 adopt an inclined wall small arc transition configuration and / or a straight wall straight line transition configuration.

6. A method for designing drag reduction of key configurations in a bogie region according to claim 5, characterized in that: In S2, carriage 3 adopts a straight-wall straight-line transition configuration, and the other carriages adopt an inclined-wall small-arc transition configuration.

7. A method for designing drag reduction of key configurations in a bogie region according to claim 6, characterized in that: The bogie bottom plate configurations in S3 include a sunken split bottom plate configuration, a flush split bottom plate configuration and a flush integrated bottom plate configuration.

8. A method for designing drag reduction of key configurations in a bogie region according to claim 7, characterized in that: The S3 adopts a flush integrated floor configuration, which has the best drag reduction effect for the entire vehicle.

9. A method for designing drag reduction of key configurations in a bogie region according to claim 8, characterized in that: The combination configuration schemes of the bogie bottom plate in S4 include skirt plate covering, head and tail covering, trailer covering, and full vehicle covering; In the skirt covering, no car is provided with a bogie bottom plate configuration; in the head and tail covering, car 1 and car 8 are provided with a bogie bottom plate configuration; in the trailer covering, car 1, car 3, car 6, and car 8 are provided with a bogie bottom plate configuration; in the full car covering, all cars are provided with a bogie bottom plate configuration; The bogie bottom plate configuration is a flush integrated bottom plate configuration.

10. A bogie region key configuration drag reduction design method according to claim 9, characterized in that: In S4, head and tail wrapping or trailer wrapping is used.

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