Air ducting for a motor vehicle

Abstract

Air guide for a motor vehicle, wherein the air guide comprises a base body (100; 200) designed to guide an airflow occurring during the intended operation of the motor vehicle, wherein the air guide comprises turbulence elements (201) designed to cause turbulence in the airflow, wherein the turbulence elements (201) are spaced apart from one another in the transverse direction of the motor vehicle when attached to the motor vehicle, such that spaces (202) are arranged between the turbulence elements (201), wherein the spaces widen continuously downstream in a first region in the direction of airflow (A) and have a constant width in a second region, wherein the second region is arranged downstream from the first region in the direction of airflow (A), wherein the first region comprises two sub-regions.wherein the gaps in the first sub-area widen less than in the second sub-area, wherein the vortex elements (201) each have a height that is at least one quarter of the height (R) of the base body (100; 200), wherein the vortex elements (201) each have a length that is 1.5 times to 2.5 times the height (R) of the base body (100; 200), wherein the gaps (202) widen from a width between one fifth and one third of the height (R) of the base body (100; 200) to a width between 1.5 times and twice the height of the base body (100; 200), wherein the vortex elements (201) each have a width (b, V ) between 1.5 times and 2.5 times the height (R) of the base body.

Description

[0001] The invention relates to an air guide for a motor vehicle according to the preamble of claim 1.

[0002] In the prior art, such air guides are also known as wings or spoilers. JP 5303598 B2 discloses a spoiler in the rear area of ​​a motor vehicle with a concave profile. The height of the spoiler also changes in the lateral direction of the motor vehicle.

[0003] Spoilers or wings can be a source of noise that varies with vehicle speed. This is due to regularly pulsating airflow separation that can form on the spoiler or wing. Vortices often develop at the trailing edge of the spoiler or wing. Through interaction with the vehicle structure, the resulting noise is transmitted into the passenger compartment.

[0004] Various measures to reduce these noise disturbances are known from the prior art. DE 100 28 178 A1 and EP 0 273 850 B1 disclose turbulence elements in the form of several nozzle-like channels. It is also known to vary the height of the spoiler along its length. The existing possibilities for noise reduction are limited by manufacturability, design, and legislation.

[0005] Therefore, the present invention aims to create further possibilities for reducing disturbing noises occurring in air guides during the operation of the motor vehicle.

[0006] This problem is solved by an air guide according to claim 1. Embodiments of the invention are specified in the dependent claims.

[0007] The air guide comprises a base body designed to direct the airflow that occurs during the intended use of the motor vehicle. For the purposes of this description, intended use of the motor vehicle is understood to mean, in particular, driving in the forward direction.

[0008] When the device is attached to a motor vehicle, its base body can have a continuously changing height in the transverse direction of the vehicle. For the purposes of this description, the height of the base body is understood to be its dimension in the vertical direction of the motor vehicle.

[0009] This design of the base body reduces or eliminates the regularity of flow separation at the base body, resulting in less noise.

[0010] The air guide comprises, preferably arranged on the base body, vortex elements. These are designed to create turbulence in the airflow guided by the base body. When the device is attached to the vehicle, the vortex elements are spaced apart from one another in the transverse direction of the vehicle. Between the vortex elements are gaps that widen continuously downstream in a first region in the direction of airflow and have a constant width in a second region. The second region is arranged downstream from the first region in the direction of airflow. This arrangement ensures that the gaps are particularly effective in reducing unwanted noise. Preferably, the first region extends over more than half the length of the vortex elements.When the motor vehicle is used as intended, the airflow direction runs along the longitudinal axis of the motor vehicle towards the rear of the vehicle.

[0011] In this description, "widening of the gaps" refers specifically to the increasing size of the gaps in the transverse direction of the vehicle. Conversely, "narrowing of the gaps" refers specifically to the decreasing size of the gaps in the transverse direction of the vehicle.

[0012] The vortex elements with their widening gaps are particularly effective because, viewed in the direction of airflow, flow separation is generated at the edges of the gaps, creating additional low pressure in each gap through edge vortices. These edge vortices guide the airflow through the gaps. Therefore, the edge vortices disrupt the regularly pulsating flow separation at the base structure, thus reducing noise.

[0013] The vortex elements with their narrowing gaps are particularly effective because the flow is locally accelerated through these narrowing spaces, resulting in a faster air jet behind them than in areas of normal outflow. These disruptive flows have a disruptive effect on the regularly pulsating flow separation at the base body, thereby reducing noise.

[0014] The first area comprises two sub-areas. The spaces between the gaps widen less in the first sub-area than in the second. In this description, the degree of widening refers specifically to the widening of the gaps per unit length.

[0015] It is particularly advantageous if the vortex elements are arranged in an area on the base body where the base body has a relatively low gradient of height change in longitudinal section.

[0016] The vortex elements each have a height that is at least one quarter of the height of the base body. Tests have shown that this is particularly advantageous for reducing unwanted background noise.

[0017] The turbulence elements each have a length that is 1.5 to 2.5 times the height of the base body. Tests have shown that this is particularly advantageous for reducing unwanted noise. The length, when the device is attached to the vehicle, refers to the extension of the turbulence elements in the longitudinal direction of the vehicle.

[0018] The gaps widen from a width of between one-fifth and one-third of the base body's height to a width of between 1.5 and twice the base body's height. Tests have shown that this is particularly advantageous for reducing unwanted background noise.

[0019] The vortex elements each have a width between 1.5 and 2.5 times the height of the base body. Tests have shown that this is particularly advantageous for reducing unwanted background noise.

[0020] According to one embodiment of the invention, the turbulence elements can be arranged in a rear region of the base body when the air guide is attached to the motor vehicle. The rear region can, in particular, be the rear half of the base body in the direction of travel of the motor vehicle. It is especially advantageous if the rear region comprises only the rear third or the rear quarter of the base body. This further reduces noise, as the regularly pulsating flow separation at the base body is more effectively disrupted.

[0021] According to one embodiment of the invention, the turbulence elements can be arranged on a surface of the air guide that is directed upwards when the air guide is attached to the motor vehicle.

[0022] According to one embodiment of the invention, the turbulence elements can be arranged on a downward-facing surface of the air guide when the air guide is attached to the motor vehicle. This arrangement is particularly advantageous for optical reasons, as this surface is usually less visible.

[0023] According to one embodiment of the invention, the vortex elements can have different spacings from one another, different heights, different lengths, and / or different widths. Tests have shown that this is particularly advantageous for reducing unwanted background noise.

[0024] The air guide can be designed to direct the airflow in such a way that a downward force acts upon it. This force can improve the vehicle's handling, particularly when cornering.

[0025] Further features and advantages of the present invention will become clear with reference to the following description of preferred embodiments and the accompanying figures. The same reference numerals are used for identical or similar components and for components with identical or similar functions. Fig. Figure 1 shows a schematic front view of a basic body with a height that changes continuously in the transverse direction of the motor vehicle. Fig. Figure 2 shows a schematic perspective view of the underside of a basic body with vortex elements arranged on it. Fig. Figure 3 shows a schematic top view of the turbulence elements made of Fig. 2. Fig. Figure 4 shows a schematic side view of the basic body made of Fig. 2. Fig. Figure 5 shows a schematic perspective view of the underside of a basic body with vortex elements arranged on it. Fig. Figure 6 shows a schematic top view of the turbulence elements made of Fig. 5.

[0026] The in Fig. The basic body 100 shown has a surface extending over its width b. G changing height R. The width b G This dimension extends laterally across the vehicle when attached. The height R changes across the entire width b. G continuous. In the middle, the base body 100 has the smallest height R and at its outer ends the greatest height R. This shape has proven particularly advantageous in tests for reducing background noise.

[0027] The one in the Fig. The basic body 200 shown in Figures 2 to 4 has vortex elements 201 on its underside with spaces 202 arranged between them. The spaces 202 are arranged between the vortex elements 201 in the transverse direction of the motor vehicle.

[0028] In the direction of airflow A of the airflow occurring during the intended operation of the motor vehicle, the turbulence elements 201 have a width b V a tapered shape. The spaces 202 between the vortex elements 201 thus widen downstream in the flow direction A.

[0029] Such vortex elements 201 and gaps 202 cause flow separation downstream in the direction of flow A at the beginning of the gaps 202 and at the side edges of the gaps 202, so that an additional low pressure is generated in each of the gaps 202 by edge vortices. The edge vortices escort the airflow through the gaps 202. The edge vortices have a disruptive effect on the regularly pulsating flow separation at the base body 200, thereby reducing noise.

[0030] The change in width b V The movement of the turbulence elements 201 and the spaces between them 202 occurs continuously in a first area, at the front when the vehicle is attached. In a second area, at the rear when the vehicle is attached, the width b remains constant. V the turbulence elements 201 and the spaces between them 202 remain constant.

[0031] In the first area, the reduction of width b V The vortex elements 201 are more pronounced in the flow direction A in a first sub-section than in a subsequent second sub-section. The first sub-section comprises the leading end of the vortex elements 201. The second sub-section adjoins the first sub-section. The second sub-section adjoins the second sub-section.

[0032] The in the Fig. The form of the turbulence elements 201 shown in Figures 2 to 4 has proven particularly suitable in tests for reducing unwanted noise in motor vehicles. It is especially advantageous if the turbulence elements 201 are combined with the form shown in Figures 2 to 4. Fig. The change in the height of the base body shown in 1 can be combined with 100.

[0033] In the Fig. 5 and Fig. Figure 6 shows another embodiment of the vortex elements 201. These can also be used, as in Fig. 4 shown, located on the underside of the base body 200.

[0034] The turbulence elements 201 from the Fig. 5 and Fig. 6 differ essentially from those from the Fig. 2 to 4 by narrowing the space 202 between the vortex elements 201 in the direction of flow A. Such vortex elements 201 and spaces 202 locally accelerate the flow, resulting in a faster air jet behind these spaces 202 than in the areas of normal outflow. These disruptive flows have a disruptive effect on the regularly pulsating flow separation at the base body 200, thereby reducing noise. This shape has proven particularly advantageous in tests for reducing noise in motor vehicles. It is especially advantageous if the vortex elements 201 are connected to the Fig.The change in the height of the base body shown in 1 can be combined with 100.

Claims

[1] Air guide for a motor vehicle, wherein the air guide comprises a base body (100; 200) designed to guide an airflow occurring during the intended operation of the motor vehicle, wherein the air guide comprises turbulence elements (201) designed to cause turbulence in the airflow, wherein the turbulence elements (201) are spaced apart from one another in the transverse direction of the motor vehicle when attached to the motor vehicle, such that spaces (202) are arranged between the turbulence elements (201), wherein the spaces widen continuously downstream in a first region in the direction of airflow (A) and have a constant width in a second region, wherein the second region is arranged downstream from the first region in the direction of airflow (A), wherein the first region comprises two sub-regions,wherein the gaps in the first sub-area widen less than in the second sub-area, wherein the vortex elements (201) each have a height that is at least one quarter of the height (R) of the base body (100; 200), wherein the vortex elements (201) each have a length that is 1.5 times to 2.5 times the height (R) of the base body (100; 200), wherein the gaps (202) widen from a width between one fifth and one third of the height (R) of the base body (100; 200) to a width between 1.5 times and twice the height of the base body (100; 200), wherein the vortex elements (201) each have a width (b, V ) between 1.5 times and 2.5 times the height (R) of the base body. [2] Air guide according to the preceding claim, characterized by, that the turbulence elements (201) are arranged in a rear area of ​​the base body (100; 200) when the air guide is attached to the motor vehicle. [3] Air guide according to one of the two preceding claims, characterized by , that the turbulence elements (201) are arranged on a surface of the air guide facing downwards or upwards in the state of the air guide being attached to the motor vehicle. [4] Air guide according to any one of the preceding claims, characterized by , that the vortex elements (201) are arranged at different distances from each other and / or that the vortex elements have different widths, heights and / or lengths.

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