EP4405236A1 - Motor vehicle with vortex generator on wheel arch - Google Patents

Abstract

The invention relates to a motor vehicle (2) comprising a left wheel (4) and a right wheel on a single axle; a wheelhouse surrounding each of the left (4) and right wheels, respectively; a wing (6) connecting with each of the two wheelhouses, respectively, and forming an arch (6.1) around the corresponding left (4) or right wheel; and an aerodynamic device (10) in front of at least one of the two left (4) and right wheels, on the arch (6.1) of the corresponding wing (6), and configured, when the vehicle (2) is moving forwards, to divert an airflow downwards along said wing (6) and to form, downstream of the arch (6.1), auxiliary vortices (14) rotating, in front view, in the anti-clockwise direction for the left wheel (4) or in the clockwise direction for the right wheel.

Description

DESCRIPTION

TITLE: MOTOR VEHICLE WITH VORTEX GENERATOR ON WHEEL ARCH

Technical area

The present invention claims the priority of French application 2109955 filed on September 22, 2021, the content of which (text, drawings and claims) is incorporated herein by reference. The invention relates to the field of motor vehicles, more particularly the bodywork of motor vehicles and its aerodynamics.

Prior technique

In motor vehicles, the wheel arch and more particularly the empty space of material located between the perimeter of the wheel and the wheel arch, commonly referred to as "wheel black" (by analogy to the fact that this area is particularly dark ), poses aerodynamic problems. When the vehicle is moving, in forward gear, the air flow generated by this movement is disturbed as it passes through this empty space called "wheel black" essentially in that this space forms a cavity and also in that this cavity is delimited by the wheel arch forming a curved profile. The flow along this cavity generates vortices and the delimitation of the cavity by a curved profile has the effect of making these vortices complex. However, these vortices are penalizing in that they generate a drag, that is to say a force opposing the movement of the vehicle. It is therefore generally desirable to reduce the vortices generated on a vehicle body when the latter is moving.

The published patent document FR 3 059 974 A1 discloses a motor vehicle front fender trim, intended to cover the wheel arch and forming two air passages generally aligned on either side of the wheel. These air passages are intended to reduce turbulence in the flow along the wheel, in particular when passing through the empty space called “wheel black”. This solution is interesting but restrictive in particular in that to be effective, the trim must be quite bulky, especially on the rear part of the arch.

The published patent document DE 10 2014 119 023 A1 discloses a motor vehicle front wing comprising an air passage from the empty space called "black wheel” to the vents formed in an upper and rear part of the front fender. This solution is also intended to channel the air flow in order to limit turbulence and the formation of vortices forming a drag. It is interesting but has the drawback of being expensive in that it requires a major modification of the wing. The presence of vents on the wing can also be undesirable, depending in particular on the style desired for the motor vehicle.

Disclosure of Invention

The invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More particularly, the aim of the invention is to reduce the drag induced by the flow of air along a wheel of a motor vehicle.

The subject of the invention is a motor vehicle comprising a left wheel and a right wheel on the same axle; a wheel arch surrounding each of the left and right wheels, respectively; a wing connecting with each of the two wheel arches, respectively, and forming an arch around the corresponding left or right wheel; remarkable in that the motor vehicle further comprises an aerodynamic device at the front of at least one of the two left and right wheels, on the arch of the corresponding wing, and configured for, when the vehicle is moving in forward motion, deflecting a flow of air along said wing downwards and forming, downstream of the arch, auxiliary vortices rotating, in front view, in the anti-clockwise direction for the left wheel or in the clockwise for the right wheel.

The axle can be a front axle or a rear axle. The left and right wheels can therefore be front wheels or rear wheels.

According to an advantageous embodiment of the invention, the at least one aerodynamic device comprises guide walls inclined downwards with respect to a horizontal direction, from front to rear.

Advantageously, the number of guide walls greater than or equal to 3 and/or less than or equal to 10.

According to an advantageous embodiment of the invention, the inclinations of the guide walls are between 10° and 45°. According to an advantageous embodiment of the invention, the guide walls project from the outer surface of the or each of the wings.

Advantageously, at least one or each of the guide walls has a laterally outer edge which is free. By free, we mean that this edge is not connected to other elements.

According to an advantageous embodiment of the invention, the guide walls are distributed along the corresponding arch. The distribution is advantageously homogeneous. By homogeneous distribution, it can be understood that the distance between each pair of directly adjacent guide walls does not vary by more than 20%, preferably 10%, over the extent of the aerodynamic device along the arch.

According to an advantageous embodiment of the invention, the guide walls are formed on a support arranged on the corresponding arch.

According to an advantageous mode of the invention, the support forms a trim of the arch.

According to an advantageous embodiment of the invention, the at least one aerodynamic device extends vertically over an upper half of the corresponding wheel. Advantageously, the at least one aerodynamic device extends vertically mainly or exclusively over the upper half of the corresponding wheel.

The invention also relates to a trim for the left or right wing of a vehicle body, said wing forming an arch around a corresponding wheel of said vehicle, said trim comprising an elongated and curved wall, intended to hug the arch; an aerodynamic device on the elongated and curved wall; remarkable in that the aerodynamic device is configured so as, when the vehicle is moving forward, to deflect a flow of air along said wing downwards and to form, downstream of the arch, auxiliary rotating vortices, front view, anti-clockwise for the left wing and clockwise for the right wing.

According to an advantageous embodiment of the invention, the aerodynamic device comprises guide walls distributed over the elongated wall and inclined downwards with respect to a horizontal direction, from front to rear, when the trim is in position disassembly. The aforementioned characteristics in relation to the motor vehicle apply to the hubcap.

The measures of the invention are advantageous in that they make it possible to reduce the drag induced by the empty space of material between the wheel and the arch, commonly referred to as “wheel black”. They are advantageous in that they can be implemented in a simple and economical manner. The aerodynamic device is in fact advantageously attached to the corresponding wing of the bodywork, more advantageously still, it is part of a trim of the arch. The aerodynamic device is advantageously produced by injection of plastic material. It is also advantageously compact and inconspicuous.

Brief description of the drawings

[Fig 1] is a perspective view of a left front part of a motor vehicle according to the invention;

[Fig 2] is a side view of the left front part of the vehicle of Figure 1;

[Fig 3] is a perspective representation of one of the guide surfaces of the aerodynamic device shown in Figures 1 and 2;

[Fig 4] is a perspective view of a left front part of a motor vehicle according to a variant of the invention.

detailed description

Figures 1 and 2 are two views of a left front part of a vehicle according to the invention, Figure 1 being a perspective view and Figure 2 being a side view.

The motor vehicle 2 comprises a left front wheel 4, a wheel arch surrounding the wheel, and a left front fender 6 connecting with the wheel arch and forming an arch 6.1 around the wheel 4. The empty space of material 8 between the periphery or perimeter of the wheel 4 and the arch 6.1 is commonly referred to as “wheel black”, in reference to the fact that this space is dark. It has an annular profile around an upper sector of the wheel 4. It is delimited within it by the wheel arch. The latter is a wall, formed by one or more assembled sheets, forming a generally circular box and separating the clearance space of the wheel from the engine compartment. When the motor vehicle is moving forward, the flow of air along the front fender 6, generated by the movement of the vehicle, causes the passage of the “wheel black” 8 to cause disturbances generating various vortices. The inventors have carried out theoretical and experimental studies and have observed that the air flow downstream of the rear part of the arch 6.1 forms at least one drag vortex 12 rotating around a generally horizontal direction and winding clockwise, seen from the front of the vehicle. The genesis of this or these trailing vortices is complex. It is essentially due to the non-rectilinear profile of the rear part, essentially the rear half, of the arch 6.1. This descending profile, in the main direction of air flow along the front wing 6 (essentially horizontal from the front to the rear), in fact favors a lateral return towards the outside in the upper part flow while the lower part is still along wheel 4 or "wheel black" 8, in any event has not yet encountered the arch in its lower part. This phenomenon explains the formation of the drag vortex or vortices 12 oriented essentially horizontally and rotating clockwise, seen from the front of the vehicle.

The aforementioned studies have shown the formation, essentially, of two drag vortices 12, namely an upper drag vortex 12.1 and a lower drag vortex 12.2, the latter being of greater intensity.

However, the formation of drag vortices 12 as mentioned above generates a resisting force opposed to the movement of the vehicle.

To this end, the motor vehicle further comprises an aerodynamic device 10 arranged at the front of the wheel 4, advantageously on a front half of the arch 6.1, and configured to deflect the flow of air along the front wing downwards and form, downstream of the arch, auxiliary vortices 14 rotating in the opposite direction to the drag vortex(es) 12, capable of interacting in a destructive manner with this or these vortices of drag 12, i.e. decreasing, or even canceling, this or these drag vortices 12.

In the absence of the aerodynamic device 10 deflecting the airflow downwards, the lower part of the airflow meets the lower part of the arch 6.1 and then the "wheel black" 8 before the part high. The lower part then rushes into the "wheel black" 8 while the upper part is still opposite the front wing 6. This may result in a start of rotation in the clockwise direction, tending to reinforce the drag vortex or vortices 12 mentioned above. The downward deviation of the flow along the "wheel black" 8, and this in a local way, makes it possible to cancel this phenomenon and makes it possible, moreover, to generate a series of auxiliary vortices 14 rotating in the opposite direction. , namely the anti-clockwise direction, seen from the front of the vehicle.

In this case, the aerodynamic device 10 comprises a series of guide walls 10.1 inclined downwards relative to the horizontal, from the front to the rear of the vehicle, that is to say in the direction of airflow when the vehicle is moving forward. These guide walls 10.1 are distributed along the arch, advantageously being adjacent to the edge of the arch 6.1. They project outwardly from the front wing 6. Each fluid vein delimited by two adjacent guide walls and by the projecting height of said walls is deflected downwards while the part of the flow d the directly adjacent air flowing laterally away from the guide walls 10.1 is not deflected. The contact zone between these downwardly deviated fluid veins and the adjacent layer of the air flow favors the formation of the vortices 14 winding around essentially horizontal directions and in an anti-clockwise direction, seen from the front of the vehicle. .

The number of guide walls 10.1 of the aerodynamic device 10 illustrated in FIGS. 1 and 2 is four, it being however understood that this number may be different, namely larger or smaller.

The guide walls 10.1 can take different sizes and shapes. They are advantageously triangular with the base of the triangle located on the front fender 6, an acute angle formed with the base and located upstream. The acute angle in question is advantageously less than 45°. Such a configuration provides an increasing profile as the air flow along the guide walls 10.1. It also avoids the formation of bumps directed forwards, which can be potentially blunt and therefore dangerous. It is understood that the triangular shape may be approximate in that the sides of this triangular shape may not be straight while being generally elongated. The inclination of the guide walls 10.1 with respect to the horizontal is illustrated in FIG. 2. It is advantageously greater than 10° and/or less than 45°. Too low an inclination, in this case less than 10°, is in fact likely not to sufficiently form the auxiliary vortices 14 and therefore not to sufficiently reduce the drag vortex or vortices 12. Also, too great an inclination, in the occurrence greater than 45°, is likely to generate stalls of the fluid streams and undesirable turbulence, without increasing the effectiveness of the auxiliary vortices 14.

The guide walls 10.1 are advantageously formed on a support 10.2 forming part of the aerodynamic device 10. The support 10.2 advantageously extends over part of the arch 6.1. The guide walls 10.1 and the support 10.2 can form a single piece, in particular produced by plastic injection. Advantageously, the support 10.2 is part of a trim 16 of the front fender 6. The trim 16 comprises an elongated and curved wall 16.1 extending over the arch and integrating the support 10.2.

The aerodynamic device 10 is advantageously positioned so as to be aligned with an upper half of the wheel 4. The objective is in fact to form the auxiliary vortices 14 at the height of the drag vortices 12, these being located, in height, also on the upper half of wheel 4.

Figure 3 is a perspective representation of one of the guide surfaces 10.1 of the aerodynamic device 10 illustrated in Figures 1 and 2.

The guide surface 10.1 is of triangular shape, the base 10.1.1 of which forms with the other two sides 10.1.3 and 10.1.2 an acute angle and an angle close to 90°, respectively. By close to 90°, we can understand between 80° and 100°. For example, the base 10.1.1 may have a length of 24mm, the short side 10.1.2 a length of 12mm and the large side 10.1.3 a length of 29mm. The short side 10.1.2 thus determines the height of the guide walls, considered projecting from the outer surface of the front wing 6. The aforementioned values are illustrative, it being understood that they may deviate from these specific values.

Figure 4 is a perspective view of a left front part of a motor vehicle according to a variant of the invention. The aerodynamic device 10' differs from the aerodynamic device 10 in that the number of guide walls 10.1 is greater. The latter are in this case 9 in number and are distributed over a larger section of the arch 6.1, this section in fact extending over the entire upper half of the wheel 4. It can be observed that the guide walls 10.1 may have different inclinations, while each being inclined downward relative to the horizontal direction, from front to back.

The construction of the aerodynamic device detailed above, that is to say with guide walls projecting from a support on the arch, is an example of embodiment, it being however understood that numerous alternatives and variants capable of producing auxiliary vortices 14 (FIG. 1) are possible. By way of example, guide surfaces of more complex shapes, such as in particular skew surfaces, can be envisaged.

The description given above in relation to the left side of the motor vehicle is also valid for the right side, it being then understood that the directions of rotation of the drag vortices and of the auxiliary vortices are reversed.

Also, the description given above in relation to the front wheels of the motor vehicle also applies to the rear wheels.

Claims

[Claim 1.] Motor vehicle (2) comprising: - a left wheel (4) and a right wheel on the same axle; - a wheel arch surrounding each of the left (4) and right wheels, respectively; - a wing (6) connecting with each of the two wheel arches, respectively, and forming an arch (6.1) around the corresponding left (4) or right wheel; characterized in that the motor vehicle (2) further comprises: - an aerodynamic device (10; 10') in front of at least one of the two left (4) and right wheels, on the arch (6.1) of the corresponding wing (6), and configured for, when the vehicle (2) moves forward, deflecting an air flow along said wing (6) downwards and forming, downstream of the arch (6.1), auxiliary vortices (14) rotating, front view, anti-clockwise for the left wheel (4) or clockwise for the right wheel. [Claim 2.] Motor vehicle (2) according to claim 1, in which the at least one aerodynamic device (10; 10') comprises guide walls (10.1) inclined downwards with respect to a horizontal direction, front to back. [Claim 3.] Motor vehicle (2) according to claim 2, in which the inclinations of the guide walls (10.1) are between 10° and 45°. [Claim 4.] Motor vehicle (2) according to one of Claims 2 and 3, in which the guide walls (10.1) project from the outer surface of the or each of the wings (6). [Claim 5.] Motor vehicle (2) according to one of Claims 2 to 4, in which the guide walls (10.1) are distributed along the corresponding arch (6.1). [Claim 6.] Motor vehicle (2) according to one of claims 2 to 5, wherein the guide walls (10.1) are formed on a support (10.2) disposed on the corresponding arch (6.1). [Claim 7.] Motor vehicle (2) according to claim 6, wherein the support (10.2) forms a trim (16) of the arch (6.1). [Claim 8.] Motor vehicle (2) according to one of Claims 1 to 7, in which the at least one aerodynamic device (10; 10') extends vertically over an upper half of the left wheel (4) or corresponding line. [Claim 9.] Trim (16) of the left (6) or right wing of the vehicle body (2), the said wing (6) forming an arch (6.1) around a corresponding wheel (4) of the said vehicle, the said trim (16) comprising: - an elongated and curved wall (16.1), intended to hug the arch; - an aerodynamic device (10; 10') on the elongated and curved wall (16.1); characterized in that the aerodynamic device (10; 10') is configured to, when the vehicle (2) is moving forward, deflect an air flow along the wing (6) downwards and form, downstream of the arch (6.1), auxiliary tourbillons (14) rotating, in front view, in the anti-clockwise direction for the left wing (6) or in the clockwise direction for the right wing. [Claim 10.] Trim (16) according to claim 9, in which the aerodynamic device (10; 10') comprises guide walls (10.1) distributed over the elongated and curved wall (16.1) and inclined downwards with respect to in a horizontal direction, from front to rear, when the trim (16) is in the mounting position.