Aerodynamic motor vehicle roof insulator structure

Abstract

This invention discloses an aerodynamic train roof insulator structure, comprising: a core rod body, sheds, and protrusions; the sheds include multiple large sheds and multiple small sheds, which are evenly spaced on the outer wall of the core rod body, and are staggered and parallel to each other; multiple protrusions are provided, and the protrusions are evenly arranged on the upper surfaces of the large and small sheds. By arranging multiple protrusions on the upper surfaces of the large and small sheds, when airflow passes over the surface, small turbulence appears in the gaps between the protrusions, forming a negative pressure zone. The small turbulence drives the airflow, and the negative pressure attracts the airflow; under the combined effect of these two factors, the airflow can be brought closer to the surface of the protrusions, thus delaying boundary layer separation. This delayed boundary layer separation greatly reduces the turbulence area on the leeward side, improves the airflow environment on the leeward side, and thus reduces the adhesion of contaminants to the insulator surface.

Description

Technical Field

[0001] This invention relates to the field of high-speed train technology, specifically to an aerodynamic high-speed train roof insulator structure. Background Technology

[0002] The description of the background art in this invention pertains to related technologies and is used merely for illustration and to facilitate understanding of the invention. It should not be construed as the applicant explicitly believing or presuming that the invention was prior art on the filing date of the first application.

[0003] With the continuous development of my country's economy, my country's high-speed railway has also developed rapidly due to its advantages such as large carrying capacity and high speed. However, as the speed of high-speed trains continues to increase, the flow field environment of the train roof insulators also shows significant differences. Therefore, improving the aerodynamic performance of the roof insulators has gradually become a key aspect of high-speed train design. On the one hand, as the train speed increases, the resistance experienced by the train also increases. Studies have shown that the resistance experienced by the equipment on the train roof accounts for 5%-8% of the total resistance experienced by the train. On the other hand, as the train speed increases, the flow field environment near the roof insulators becomes more complex, easily leading to turbulence and vortices. This makes it easier for pollutants in the environment to adhere to the insulator surface, potentially causing accidents. Therefore, optimizing the structure of the roof insulators from the perspective of improving their aerodynamic performance has strong practical significance.

[0004] Studies on the flow motion around bluff bodies have shown that, compared to smooth surfaces, rough surfaces alter the aerodynamic properties and turbulence intensity of objects in high-speed airflow environments. Appropriately increasing surface roughness can reduce aerodynamic drag and improve flow field distribution. Due to the unique characteristics of roof insulators, their height and accessories are generally fixed. Therefore, considering current research and the structural limitations of roof insulators, this invention focuses on roof insulators and provides new ideas for improving the aerodynamic performance of external roof insulation equipment and high-speed trains while ensuring their insulation performance. Summary of the Invention

[0005] The purpose of this invention is to provide an aerodynamic vehicle roof insulator structure to solve the problem that existing vehicle roof insulators are prone to turbulence and vortex formation, which makes it easier for environmental pollutants to adhere to the insulator surface.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] An aerodynamic type electric vehicle roof insulator structure includes: a core rod body, a skirt, and a bulge;

[0008] The umbrella skirt includes multiple large umbrella skirts and multiple small umbrella skirts. The large umbrella skirts and small umbrella skirts are evenly spaced on the outer wall of the core rod body. The large umbrella skirts and small umbrella skirts are staggered and parallel to each other.

[0009] There are multiple convex hulls, and these convex hulls are evenly arranged on the upper surfaces of the large umbrella skirt and the small umbrella skirt.

[0010] This invention incorporates multiple protrusions arranged on the upper surfaces of the large and small umbrella skirts. These protrusions increase the thickness of the skirts, thereby enhancing their strength under high-speed airflow conditions. Furthermore, the protrusions on the upper surfaces of both skirts increase their roughness. Compared to a smooth surface, when airflow passes over the surface, small turbulence occurs in the gaps between the protrusions, creating a negative pressure zone. The combined effect of this small turbulence driving the airflow and the negative pressure adsorbing it allows the airflow to adhere more closely to the protrusion surfaces, thus delaying boundary layer separation. This delayed boundary layer separation significantly reduces the turbulence area on the leeward side, ultimately improving the airflow environment on the leeward side and reducing contaminant adhesion to the insulator surface.

[0011] Furthermore, the convex hulls are arranged radially along the upper surfaces of the large and small umbrella skirts, respectively.

[0012] Furthermore, multiple convex hulls are arranged as adjacent long column convex hulls and short column convex hulls.

[0013] Furthermore, the circumferential array angle α between the long column convex hull and the short column convex hull is 3° to 6°.

[0014] Furthermore, the convex hull has a hemispherical structure.

[0015] Furthermore, the lateral spacing L between adjacent convex hulls on the same array is 0.1 mm to 1 mm.

[0016] Furthermore, the diameter D of the convex hull is 1mm to 2mm.

[0017] Furthermore, the depth H of the convex hull is 0.5mm to 1mm.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention provides an aerodynamic type insulator structure for the roof of a high-speed train. By setting protrusions on the surfaces of the large and small umbrella skirts, the aerodynamic performance of the roof external insulation equipment and the train is improved without affecting the electrical insulation performance.

[0020] 2. The aerodynamic train roof insulator structure provided by this invention improves insulation performance by increasing the creepage distance from 1220mm to 1445.5mm, an improvement of 18.5%. In terms of drag reduction, the drag coefficient is reduced from 0.277 to 0.260 in an airflow environment at 80m / s altitude, a reduction of 6.14%. Regarding improved airflow environment, the concentration of vortices near the root of the leeward side skirt, where dirt accumulation is prone to occur, disappears, and there are no obvious vortices. In terms of structural strength, the presence of the hemispherical bulge increases the skirt thickness, thereby increasing the skirt's strength to a certain extent in high-speed airflow environments.

[0021] 3. The present invention adds a hemispherical convex structure to the surface of the umbrella skirt, which essentially increases the roughness of the upper surface of the umbrella skirt. The presence of the convex bulge causes the airflow to deflect into the gap between the convex bulges when passing over the surface, thereby forming a low-speed small vortex in the gap, thus forming a "vortex pad effect", thereby reducing the viscous force between the airflow and the surface of the insulator and achieving the effect of drag reduction. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the roof insulator.

[0023] Figure 2 This is a top view schematic diagram of the roof insulator structure;

[0024] Figure 3 A schematic diagram of the convex hull on the upper surface of the umbrella skirt;

[0025] Figure 4 This is a schematic diagram of the original roof insulator used for simulation.

[0026] Figure 5 This is a schematic diagram of the structure of a convex-shaped roof insulator used for simulation.

[0027] Figure 6 Schematic diagram of the principle of improving the airflow environment on the leeward side using a convex hull;

[0028] Figure 7 A diagram showing the vorticity distribution at the base of the large umbrella skirt;

[0029] Figure 8 A diagram showing the vorticity distribution at the base of the small umbrella skirt;

[0030] Figure 9 This is a diagram showing the vorticity distribution on the surface of the large umbrella skirt.

[0031] Figure 10 This is a diagram showing the vorticity distribution on the surface of the small umbrella skirt.

[0032] In the diagram: 1-core rod body, 2-large umbrella skirt, 3-convex bulge, 4-small umbrella skirt. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1 and Figure 2 As shown, the present invention provides an aerodynamic type train roof insulator structure, including: a core rod body 1, umbrella skirts, and protrusions 3; the umbrella skirts include multiple large umbrella skirts 2 and multiple small umbrella skirts 4, the large umbrella skirts 2 and small umbrella skirts 4 are evenly spaced on the outer wall of the core rod body 1, the large umbrella skirts 2 and small umbrella skirts 3 are staggered and parallel to each other, and multiple protrusions 3 are provided, and the multiple protrusions 3 are evenly arranged on the upper surface of the large umbrella skirts 2 and small umbrella skirts 4 respectively.

[0036] like Figure 3 As shown, the structure and parameters of the convex hull 3 in this embodiment are as follows:

[0037] The convex hull 3 has a hemispherical structure. The convex hull 3 are arranged radially along the upper surfaces of the large umbrella skirt 2 and the small umbrella skirt 4. The multiple convex hulls 3 are arranged as adjacent long columns and short columns of convex hulls, and the circumferential array angle α between the long column of convex hulls and the short column of convex hulls is 3° to 6°.

[0038] The lateral spacing L between adjacent convex hulls on the same array is 0.1mm to 1mm.

[0039] The diameter D of the convex hull 3 is 1mm to 2mm.

[0040] The depth H of the convex hull 3 is 0.5mm to 1mm; where H = D / 2.

[0041] The aerodynamic train roof insulator structure of the present invention features multiple protrusions 3 arranged on the upper surfaces of the large umbrella skirt 2 and the small umbrella skirt 4. The protrusions 3 increase the overall thickness of the umbrella skirt, thereby increasing its strength under high-speed airflow conditions to a certain extent. Furthermore, the protrusions 3 on the upper surfaces of the upper umbrella skirt 2 and the lower umbrella skirt 4 also increase the roughness of the upper surface of the umbrella skirt. Compared to a smooth surface, when airflow passes over the surface, small turbulence will appear in the gaps between the protrusions 3, forming a negative pressure zone. The small turbulence drives the airflow, and the negative pressure attracts the airflow. Under the combined effect of these two factors, the airflow can get closer to the surface of the protrusions 3, thereby delaying boundary layer separation. The delayed boundary layer separation greatly reduces the range of turbulence on the leeward side, ultimately improving the airflow environment on the leeward side, thereby reducing the adhesion of dirt on the insulator surface and reducing the occurrence of accidents.

[0042] Meanwhile, by adding hemispherical protrusions 3 to the surface of the umbrella skirt, the roughness of the upper surface of the umbrella skirt is essentially increased. The presence of protrusions 3 causes the airflow to deflect towards the gaps between the protrusions 3 when passing over the surface, thereby forming low-speed small vortices in the gaps and creating a "vortex pad effect". This reduces the viscous force between the airflow and the surface of the insulator, thus also achieving the effect of drag reduction.

[0043] Example 2

[0044] Example 2 is a further technical solution of Example 1.

[0045] To obtain the optimal parameters for improving the airflow environment and reducing drag in the insulator, and to increase calculation speed, the following methods were employed: Figure 4 and Figure 5 The shortened insulator shown was simulated and compared in COMSOL software. The simulation boundary conditions are set as shown in the table below.

[0046] Aerodynamic viscosity <![CDATA[1.79×10 -5 Step]]> air density <![CDATA[1.29×10kg / m 3 ]]> Computational domain size 2m×1m×1m Turbulence model k-ε model based on RANS Entry conditions Fully developed flow, inlet velocity 80m / s Export conditions Pressure is 0 Pa, suppressing backflow. wall condition No slippage, the insulator surface is considered as a wall.

[0047] The optimal parameters were finally obtained as follows: L = 0.1 mm, D = 1.6 mm, H = D / 2 = 0.8 mm, α = 3.6°.

[0048] The main purpose of improving the airflow environment is to reduce the adhesion of dirt on the surface of the insulator. Studies have shown that the root of the shed on the leeward side has a high amount of dirt accumulation under high-speed airflow conditions, and weakening the turbulence on the leeward side of the roof insulator can effectively reduce the dirt accumulation on the shed surface.

[0049] like Figures 7 to 10 As shown, where, Figure 7 In the diagram, 'a' represents the original roof insulator, and 'b' represents the convex roof insulator. Figure 8 In the diagram, a represents the original roof insulator, and b represents the convex roof insulator. Figure 9 In the diagram, a represents the original roof insulator, and b represents the convex roof insulator. Figure 10 In the diagram, 'a' represents the original roof insulator, and 'b' represents the convex-hull roof insulator. Using the convex-hull roof insulator with optimal parameters, the vortex distribution at the base and surface of the skirts was simulated and compared with the original insulator. The simulation results clearly show that the vortex on the leeward side of the original roof insulator exhibits significant concentration near the boundary layer. However, with the convex-hull insulator using optimal parameters, the vortex concentration on the leeward side disappears, regardless of the base or surface of the large skirt 2 or the small skirt 4, and there are no obvious vortices. The flow field on the leeward side is significantly improved. Combined with the correlation study between pollution accumulation and vortex, it can be inferred that the convex-hull insulator with optimal parameters has a better anti-pollution effect than the original roof insulator.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An aerodynamic type electric vehicle roof insulator structure, characterized in that, include: The core rod body (1), the umbrella skirt, and the convex bulge (3); The umbrella skirt includes multiple large umbrella skirts (2) and multiple small umbrella skirts (4). The large umbrella skirts (2) and the small umbrella skirts (4) are evenly spaced on the outer wall of the core rod body (1). The large umbrella skirts (2) and the small umbrella skirts (4) are staggered and parallel to each other. The convex bulge (3) is provided in multiple ways, and the multiple convex bulges (3) are evenly arranged on the upper surfaces of the large umbrella skirt (2) and the small umbrella skirt (4); The convex bulges (3) are arranged radially along the upper surfaces of the large umbrella skirt (2) and the small umbrella skirt (4); The multiple convex hulls (3) are arranged as adjacent long column convex hulls and short column convex hulls; The circumferential array angle α between the long column convex hull and the short column convex hull is 3° to 6°. The convex hull (3) has a hemispherical structure.

2. The aerodynamic train roof insulator structure according to claim 1, characterized in that, The lateral spacing L between adjacent convex hulls located on the same array is 0.1 mm to 1 mm.

3. The aerodynamic train roof insulator structure according to claim 1, characterized in that, The diameter D of the convex hull (3) is 1mm to 2mm.

4. The aerodynamic train roof insulator structure according to claim 1, characterized in that, The depth H of the convex hull (3) is D / 2 = 0.5 mm to 1 mm.

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