Vehicle sub-assembly

Abstract

Aspects of the present invention relate to a vehicle sub-assembly, and to a vehicle. The vehicle sub-assembly comprises an airflow device (10, fig 1) and a surface 70 of a vehicle component comprising

Description

13 03 25 TECHNICAL FIELD The present disclosure relates to a vehicle sub-assembly. Aspects of the invention relate to a vehicle sub-assembly, and to a 5 vehicle. BACKGROUND It is known to provide heating or cooling to the volume or air in the cabin of the vehicle in order to heat or cool one or more occupants in the cabin. Heating and cooling systems of this type typically consume relatively large amounts of energy, given the 10 typically large volume of air inside a vehicle cabin. It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. SUMMARY OF THE INVENTION 15 Aspects and embodiments of the invention provide a vehicle sub-assembly, and a vehicle as claimed in the appended claims. According to an aspect of the present invention there is provided a vehicle sub-assembly comprising an airflow device and a seat having a surface, the surface comprising a plurality of uniformly distributed depressions formed therein and arranged to manipulate attachment or detachment of a flow of air directed substantially parallel to or towards a portion of the surface from an outlet of the 20 airflow device, wherein each of the plurality of depressions is disposed on a vertex of a tessellating polygon. By providing a plurality of depressions in the surface, the attachment and / or detachment of the flow of air may be manipulated, thereby enhancing or otherwise manipulating the Coanda effect exhibited by the flow of air along the surface. 25 In certain embodiments, the surface is a non-planar surface and the plurality of depressions is arranged to cause the flow of air to follow contours of the surface. The Coanda effect may be exploited to cause the flow of air to follow the contours of the surface. This may facilitate airflow devices to be located away from the surface of a vehicle that it is intended to provide a flow of air across. As such, the airflow device may 30 be hidden or otherwise located away from the surface so that it does not interfere with other functions of that surface. Optionally, the tessellating polygon is one of a triangle, a square, or a hexagon. 35 In certain embodiments, successive spacings between adjacent ones of the plurality of depressions increase in at least one direction along the surface. In certain embodiments, successive spacings between adjacent ones of the plurality of depressions decrease in at least one direction along the surface. 40 In certain embodiments, spacings between adjacent ones of the plurality of depressions (72) are each between 0.5 mm and 5 mm, and optionally between 1 mm and 4 mm. 13 03 25 In certain embodiments, each of the plurality of depressions has a width between 1 mm and 5 mm, and optionally between 2 mm and 4 mm. In certain embodiments, each of the plurality of depressions has a depth between 0.1 mm and 2 mm, and optionally between 0.2 mm and 1.5 mm. In certain embodiments, at least some of the plurality of depressions are each formed as a portion of a sphere or a polyhedron. Optionally, all of the plurality of depressions are identical to one another. In certain embodiments, the plurality of depressions comprise dissimilar depressions. In certain embodiments, the surface comprises a polymeric material. In certain embodiments, the plurality of depressions are embossed into the surface. Embossing may be a particularly effective method of creating the depressions in the surface (e.g. a polymeric material such as a seat trim). The vehicle sub-assembly comprises a seat, wherein the surface is a surface of the seat. The arrangements described above are particularly suited for providing a flow of air along a surface of a seat. This may be used to provide heating or cooling to an occupant in the seat. Optionally, the seat comprises a seat pad and the surface forms a surface of the seat pad. Directing air flow along the surface of the seat pad may be a particularly effective way of providing heating or cooling to the seat occupant. Optionally, the surface of the seat pad comprises an upper surface for receiving a seated occupant and at least one side surface, and wherein the airflow device is mounted such that the outlet directs the discharged flow of air substantially parallel to or towards the at least one side surface to cause the flow of air to follow contours of the surface and flow along at least part of the upper surface. By directing the flow of air to a side surface of the seat pad, the airflow device may be positioned out of sight and / or in a location that does not interfere with other functions of the seat. Optionally, the vehicle sub-assembly comprises a connecting portion between the upper surface and each at least one side surface, wherein the connecting portion is convex. Optionally, the connecting portion forms a bolster of the seat. In certain embodiments, the vehicle sub-assembly comprises a further airflow device mounted such that the outlet of the further airflow device directs the discharged flow of air substantially parallel to or towards another of the at least one side surfaces to 2 13 03 25 cause the flow of air to follow contours of the surface and flow along at least part of the upper surface. The use of additional airflow devices may further enhance the above described advantages and may provide additional flows of air at different locations. In certain embodiments, the seat comprises a seat back and the non-planar surface forms a surface of the seat back. Directing air 5 flow along the surface of the seat back may be a particularly effective way of providing heating or cooling to the seat occupant. In certain embodiments, the surface of the seat back comprises a backrest surface for receiving a seated occupant and at least seat back side surface, and wherein the airflow device is mounted such that the outlet directs the discharged flow of air substantially parallel to or towards the at least one seat back side surface to cause the flow of air to follow contours of the surface and flow 10 along at least part of the backrest surface. By directing the flow of air to a seat back side surface of the seat back, the airflow device may be positioned out of sight and / or in a location that does not interfere with other functions of the seat. 15 Optionally, the vehicle sub-assembly comprises a seat back connecting portion between the backrest surface and each at least one seat back side surface, wherein the seat back connecting portion is convex. In such embodiments, the flow of air may advantageously be directed around the convex seat back connecting portion from the at least one side surface to the backrest surface. 20 Optionally, the seat back connecting portion forms a protruding wing of the seat. As such, the backrest surface may be separated from the outlet of the airflow device by the protruding wing and the airflow may be directed along and around the protruding wing to reach the backrest surface and any occupant in the seat. In certain embodiments, the vehicle sub-assembly comprises a further airflow device mounted such that the outlet of the further 25 airflow device directs the discharged flow of air substantially parallel to or towards another of the at least one seat back side surfaces to cause the flow of air to follow contours of the surface and flow along at least part of the backrest surface. The use of additional airflow devices may further enhance the above described advantages and may provide additional flows of air at different locations. 30 In certain embodiments, the airflow device is substantially disposed within the bounds of the seat. For example, only the outlet or a small portion of the duct may fall outside the bounds of the seat. Consequently, substantially all of the airflow device may be hidden. In certain embodiments, the vehicle sub-assembly comprises a heater and / or a cooler for heating and / or cooling the flow of air 35 prior to discharge through the outlet. In certain embodiments, the airflow device comprises an airflow generator and a duct, wherein the duct comprises an inlet at a first end and the outlet at a second end, the inlet being arranged to receive the flow of air from the airflow generator and channel the flow of air towards the outlet. 40 The presence of a duct may advantageously assist control of the direction of air from the airflow generator and out of the outlet. In certain embodiments, a first cross sectional dimension of the duct increases along a path within the duct from the inlet to the outlet, the first cross sectional dimension being orthogonal to the path at any given point along the path. 13 03 25 Alternatively, in certain embodiments, a second cross sectional dimension of the duct decreases along a path within the duct from 5 the inlet to the outlet, the second cross sectional dimension being orthogonal to the path at any given point along the path. In certain embodiments in which the first cross sectional dimension of the duct increases along the path, a second cross sectional dimension of the duct decreases along the path, the second cross sectional dimension being orthogonal to the path at any given point along the path, and wherein the second cross sectional dimension is orthogonal to the first cross sectional dimension. 10 Flaring of the duct in a first dimension and / or narrowing of the duct in a second dimension may create advantageous air flow for enhancing the Coanda effect. In certain embodiments, the outlet comprises an elongated opening. An elongated opening may provide a particularly effective 15 discharge of air that may enhance the Coanda effect. Optionally, the vehicle sub-assembly may comprise a deflector proximate to or coincident with the outlet and arranged to deflect the flow of air. The deflector may advantageously determine the direction of air from the outlet. 20 Optionally, the deflector is arranged to deflect the flow of air towards the portion of the non-planar surface. Deflecting the air towards the portion of the non-planar surface may enhance the Coanda effect. In certain embodiments, the non-planar surface has at least one convex portion, and the airflow device is arranged relative to the at least one convex portion such that, in use, the discharged flow of air follows the contours of the at least one convex portion. 25 Such embodiments may exploit the Coanda effect to effectively turn the flow of air around the corner defined by the convex portion. Optionally, the at least one convex portion has a radius of curvature of at least 10mm, or at least 15 mm. The degree of cohesion (or attachment) of the flow of air to the surface, and hence the ability to follow the convex surface, is particularly effective at such radii. 30 According to another aspect of the present invention there is provided a vehicle comprising a vehicle sub-assembly as described above. BRIEF DESCRIPTION OF THE DRAWINGS 35 One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows an airflow device according to an embodiment of the invention; 40 Figure 2 shows a cross sectional view showing a vehicle sub-assembly including part of a vehicle seat and the airflow device of Figure 1; Figure 3 shows a perspective view of the vehicle sub-assembly of Figure 2; 13 03 25 Figure 4 shows a vehicle seat incorporating a plurality of the airflow devices of claim 1; 5 Figure 5 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of the invention and that includes a surface having a radius of curvature of 5 mm; Figure 6 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of the 10 invention and that includes a surface having a radius of curvature of 10 mm; Figure 7 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of the invention and that includes a surface having a radius of curvature of 15 mm; 15 Figure 8 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of the invention and that includes a surface having a radius of curvature of 20 mm; Figure 9 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of the invention and that includes a surface having a radius of curvature of 25 mm; 20 Figure 10 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of the invention and that includes a surface having a radius of curvature of 30 mm; Figure 11 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of 25 the invention and that includes a surface having a radius of curvature of 35 mm; Figure 12 shows modelled fluid dynamics behaviour in relation to a vehicle sub-assembly in accordance with an embodiment of the invention and that includes a surface having a radius of curvature of 40 mm; 30 Figure 13 shows a portion of a surface of a vehicle component in accordance with an embodiment of the invention; Figure 14 shows a portion of a surface of a vehicle component in accordance with an alternative embodiment of the invention; Figure 15 shows a portion of a surface of a vehicle component in accordance with an alternative embodiment of the invention; 35 Figure 16 shows a portion of a surface of a vehicle component in accordance with an alternative embodiment of the invention; and Figure 17 shows a vehicle in accordance with an embodiment of the invention. 40 DETAILED DESCRIPTION 13 03 25 An airflow device 10 in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figure 1. As shown in Figures 2 and 3, the airflow device 10 forms part of a vehicle sub-assembly 50 that additionally includes a non-planar surface 63. As shown in Figure 4, the sub-assembly 50 may form part of a vehicle seat 60. The sub-assembly 50 may be installed in a vehicle 100 such as that shown in Figure 17, either as part of a vehicle seat 60 or another 5 vehicle assembly. The vehicle 100 in the present embodiment is an automobile, such as a wheeled vehicle, but it will be understood that the vehicle sub-assembly may be used in other types of vehicle, such as aircraft or watercraft. As is described in more detail below, in accordance with embodiments of the invention, the airflow device 10 is arranged relative to the non-planar surface 63 such that a discharged flow of air is directed substantially parallel to or towards a portion of the non-10 planar surface 63 to cause the flow of air to follow contours of the non-planar surface 63. In particular, embodiments of the present invention are configured to exploit the Coanda effect in order to manipulate a flow of air to follow contours of the non-planar surface 63. With reference to Figure 1, the airflow device 10 is configured to generate the flow of air that is discharged from the airflow device 15 10 through an outlet 16. In the non-limiting embodiment shown in Figures 1 and 2, the airflow device 10 comprises an airflow generator 12 for generating the flow of air and a duct 14 for channelling the flow of air from the airflow generator 12 to the outlet 16 which forms part of the duct 14. The airflow generator 12 may comprise any suitable means for generating a flow of air, including but not limited to a fan, a pump, or any device configured to create a pressure differential. 20 As shown in Figure 2, the duct 14 has an inlet 15 at a first end 14a which is connected to the airflow generator 12, and the outlet 16 is disposed at a second end 14b of the duct 14 which is opposite the first end 14a. The inlet 15 is arranged to receive the flow of air from the airflow generator 12 such that the duct 14 then channels the flow of air to the outlet 16 through which it is discharged. In the non-limiting embodiment shown in Figure 2, the airflow device 10 includes a deflector 18 at the outlet 16 that is arranged to deflect and therefore determine the direction of the flow of air as it is discharged from the outlet 16. In embodiments of the invention, 25 the deflector 18 may be any suitable component that is capable of directing the flow of air in a desired direction. Whilst in the nonlimiting embodiment of Figure 2 the deflector 18 is positioned coincidentally with the outlet 16, in alternative embodiments that include a deflector 18, the deflector 18 may be disposed proximate to, but not necessarily coincident with, the outlet 16 so as to deflect and direct the flow of air. Indeed, whilst in certain embodiments, the deflector 18 may form part of the duct 12, in other embodiments the deflector 18 may be a separate component which may optionally be positioned separately from the duct 14. In 30 certain embodiments, the airflow device 10 may be arranged relative to the non-planar surface 63 such that the flow of air discharged from the outlet 16 is directed towards the non-planar surface 63, i.e. the direction of the discharged flow of air forms an inclined angle with the portion of the non-planar surface 63 on which it is incident. In alternative embodiments, the airflow device 10 may be arranged relative to the non-planar surface 63 such that the flow of air discharged from the outlet 16 is directed substantially parallel to the non-planar surface 63. As described above, in embodiments that include a deflector 18, it is the deflector 35 18 that may determine the direction of the discharged flow or air. In the non-limiting embodiment of Figure 2, the airflow device 10 comprises a temperature controller 13 which may comprise a heater and / or cooler for heating and / or cooling the flow of air prior to discharge through the outlet 16. In such embodiments, the airflow device 10 may provide heated / cooled air to one or more vehicle occupants, and / or to the cabin of the vehicle, and / or to one 40 or more components of the vehicle. 13 03 25 As shown in Figure 2, the flow of air produced by the airflow generator 12 may follow a flow path 20 through the duct 14 and out of the outlet 16. Depending on the shape of the duct 14, the flow path 20 may not be a straight line, as demonstrated in Figure 2. The shape of the duct 14 may be formed to provide a flow of air of a desired flowrate and profile at the outlet 16. For example, with 5 reference to Figure 1, a first cross sectional dimension of the duct 14 increases along a path within the duct from the inlet 15 to the outlet 16. This is evident by a comparison of the dimensions labelled W1 and W2 in Figure 1 at the first end 14a and second end 14b of the duct 14 respectively. This first cross sectional dimension is orthogonal to the path at any given point along the path. Conversely, a second cross sectional dimension of the duct 14 decreases along a path within the duct from the inlet 15 to the outlet 16. This is evident by a comparison of the dimensions labelled L1 and L2 in Figure 1 at the first end 14a and second end 10 14b of the duct 14 respectively. The second cross sectional dimension is orthogonal to both the first cross sectional dimension and the path at any given point along the path. Flaring of the duct 14 in one dimension and narrowing of the duct 14 in the orthogonal dimension creates an airflow that enhances the downstream Coanda effect. In certain embodiments, advantageous airflows may be created by flaring of duct without narrowing 15 of the duct in an orthogonal dimension, or narrowing of the duct in one dimension without flaring of the duct in an orthogonal dimension. In certain embodiments, the outlet 16 may be otherwise configured but still comprise an elongated opening to produce a similar advantageous effect. As noted above, the airflow device 10 forms part of a vehicle sub-assembly 50 which comprises the combination of the airflow 20 device 10 and the non-planar surface 63. In the illustrated embodiments, the non-planar surface 63 is presented as a surface of a vehicle seat 60, however embodiments of the invention are not limited to such. Indeed, in alternative embodiments, the non-planar surface of the vehicle sub-assembly 50 may comprise any non-planar surface of a vehicle component along which it is desired to have a flow of air follow its contours. 25 Figure 3 shows a perspective view of the vehicle sub-assembly 50 of Figure 2, and shows part of the vehicle seat 60 and the outlet 16 and associated deflector 18 of the airflow device 10. The remainder of the airflow device 10 is not visible as it is disposed within the bounds of the vehicle seat 60 and is consequently hidden from view. As shown in Figures 2 and 3, the seat 60 comprises a seat pad 62 and the non-planar surface 63 forms a surface of the seat pad 30 62. The surface 63 of the seat pad 62 comprises an upper surface 63b for receiving a seated occupant and a pair of side surfaces 63a connected to opposite sides of the upper surface 63b along connecting portions 62a. The connecting portions 62a are generally convex such that at least part of the side surfaces 63a are approximately perpendicular to the upper surface 63b. In certain embodiments, such as that illustrated in Figures 3 and 4, the connecting portions 62a each extend from the side surfaces 63a to a height above that of the upper surface 63b and transition down to the upper surface 63b. Consequently, the connecting portions 35 62a form the surfaces of protruding bolsters at either side of the seat pad 62. The outlet 16 of the airflow device 10 passes through, or is positioned proximate to, at least one of the side surfaces 63a and is arranged (with the deflector 18, if present) to direct the discharged flow of air substantially parallel to or towards a portion of the respective side surface 63a such that the flow of air follows the contours of the surface 63 along the respective side surface 63a, 40 connecting portion 62a, and upper surface 63b. That is, by directing the flow of air substantially parallel to or towards a portion of the side surface 63a, the Coanda effect may be exploited to produce a flow of air along the upper surface 63b. Moreover, since airflow may be provided along a desired surface without initially discharging a flow of air from the airflow device 10 towards that 7 13 03 25 surface, the outlet 16 of the airflow device 10 (and indeed the whole airflow device 10 itself) may be positioned in a more discreet location within the vehicle (e.g. one that may not be visible or is less visible to a vehicle occupant). In certain embodiments, more than one airflow device 10 may be employed to provide multiple flows of air across a surface of a 5 vehicle seat 60 (or, indeed, other vehicle component). In certain embodiments, each side surface 63a of the seat pad 62 may have an associated outlet 16 of an airflow device 10, with each airflow device 10 being arranged to ultimately provide a flow of air across the upper surface 63b. In use, the flows of air may be incident on an occupant seated on the upper surface 63b. The temperature of the flows of air may be heated or cooled by the temperature controller 13 in order to provide a flow of air of a desired temperature to the occupant. 10 As shown in Figure 4, in addition to the seat pad 62, the seat 60 comprises a seat back 64 and a head restraint 66. A second non-planar surface 65 forms a surface of the seat back 64 and comprises two opposing seat back side surfaces 65a and a backrest surface 65b against which a seat occupant may rest their back. The pair of seat back side surfaces 65a connect to opposite sides of the backrest surface 65b along seat back connecting portions 64a. The seat back connecting portions 64a are generally convex 15 such that at least part of the seat back side surfaces 65a are approximately perpendicular to the backrest surface 65b. In certain embodiments, such as that illustrated in Figure 4, the seat back connecting portions 64a each extend forwardly from the seat back side surfaces 65a, forward of the plane of the backrest surface 65b. and then transition rearwardly to the backrest surface 65b. Consequently, the seat back connecting portions 64a form the surfaces of protruding wings at either side of the seat back 64. 20 Outlets 16 of additional airflow devices 10 pass through, or are positioned proximate to, at least one of the seat back side surfaces 63a and are arranged (with the deflectors 18, if present) to direct the discharged flow of air substantially parallel to or towards a portion of the respective seat back side surface 65a such that the flow of air follows the contours of the surface 65 along the respective seat back side surface 65a, seat back connecting portion 64a, and backrest surface 65b. That is, by directing the flow of air substantially parallel to or towards a portion of the seat back side surface 65a, the Coanda effect may be exploited to produce 25 a flow of air along the backrest surface 65b. In certain embodiments, each seat back side surface 65a of the seat back 64 may have an associated outlet 16 of an airflow device 10, with each airflow device 10 being arranged to ultimately provide a flow of air across the backrest surface 65b. In use, the flows of air may be incident on an upper portion of a seat occupant. The air of the flows of air may be heated or cooled by the temperature controller 13 in order to provide a flow of air of a desired temperature to the occupant. 30 In certain embodiments, the seat 60 may comprise one or more airflow devices 10 that provide a flow of air to either or both of the seat pad 62 and the seat back 64, or indeed any other part of the seat 60. Figures 5 to 12 each show a visual representation of computational fluid dynamic (CFD) modelled behaviour in relation to a vehicle 35 sub-assembly 50 in accordance with the embodiments shown in Figures 2 to 4. The shade scale on the images is “Velocity: Magnitude (m / s)”, that is, the magnitude of air velocity in metres per second. The vehicle sub-assembly 50 in each of Figures 5 to 12 has a different radius of curvature in respect of the convex connecting portion 62a connecting the side surface 63a to the upper surface 63b, and the respective Figure shows how this impacts on the flow of air from the outlet 16 along the non-planar surface 63. In Figure 5, the radius of curvature of the connecting portion 62a is 5 mm, in Figure 6 it is 10 mm, in Figure 7 it is 15 mm, in 40 Figure 8 it is 20 mm, in Figure 9 it is 25 mm, in Figure 10 it is 30 mm, in Figure 11 it is 35 mm, and in Figure 12 it is 40 mm. 13 03 25 As shown in Figure 5, at a radius of curvature of 5 mm, whilst there is some adhesion of the flow of air around the convex connection portion 62a, the flow of air detaches before reaching the upper surface 63b and so does not flow along the upper surface 63b. Figure 6 shows that at a slightly greater radius of curvature of 10 mm, the adhesion of the flow of air to the non-planar surface 63 5 causes a greater deflection (i.e. turning) of the flow of air compared with the flow shown in Figure 5. However, again, the flow of air detaches prior to reaching the upper surface 63b and so does not flow along the upper surface 63b. Nevertheless, the deflection of the direction of the flow of air due to the Coanda effect may be sufficient for directing the flow of air towards a seat occupant. In Figure 7 where the radius of curvature is 15 mm, it can be clearly seen that the Coanda effect causes the flow of air to adhere 10 to the non-planar surface 63 and follow its convex contours around the connecting portion 62a and along the upper portion 63b. This adhesion of air and the consequent flow around the connecting portion 62a and along the upper portion 63b is also exhibited at greater radii or curvature, as shown in Figures 8 to 12. 15 In certain embodiments of the invention, the non-planar surface 63 may have at least one convex portion (e.g. connecting portion 62a or seat back connecting portion 64a) that has a radius of curvature of at least 10mm. In certain embodiments, the radius of curvature of the at least one convex portion may be at least 15 mm. As described above, in use the airflow device 10 is arranged relative to the at least one convex portion such that the discharged flow of air follows the contours of the at least one convex portion. 20 In embodiments in which the non-planar surface 63 forms part of a vehicle component that a user or occupant interacts with (e.g. a vehicle seat), the presence of the user or occupant may alter the radius of curvature of a convex portion of the non-planar surface 63. In certain embodiments, therefore, the radius of curvature of a convex portion may be selected with consideration of the likely deformation caused by the presence of a user or occupant such that a desired, or at least acceptable (i.e. above a minimum 25 desired radius), radius of curvature is achieved when the user or occupant interacts with the non-planar surface 63 (e.g. when the occupant sits in the vehicle seat). As a non-limiting illustrative example, in embodiments in which the non-planar surface 63 is a surface of a vehicle seat 60, the nominal radius of curvature of the convex portion may be greater than a minimum desired radius of curvature, and a radius of curvature that is greater than the minimum desired radius of curvature may be achieved when an occupant is sat in the seat 60. The nominal radius of curvature may therefore be offset from the minimum desired radius of curvature 30 by a predetermined amount. The predetermined offset may be derived considering average characteristics (e.g. weight, size, etc.) of vehicle occupants and their effect on the non-planar surface 63, such that when the occupant interacts with the non-planar surface 63, the resultant radius of curvature remains above the minimum desired radius of curvature. As described above, varying the radius of curvature of the non-planar surface 63 may alter the position and / or distance of the 35 detachment point from the outlet 16 of the airflow device 10. Other parameters that may affect the position and / or distance of the detachment point of the flow of air include, but are not limited to, the flow rate of air discharged from the airflow device 10 and the angle of incidence of the discharged flow of air relative to the portion of the non-planar surface 63 on which it is incident. Embodiments of the invention advantageously permit an airflow along a surface from an airflow device 10 that is remote from the 40 surface. As such, the airflow device 10 may be positioned away from the surface, possibly out of sight of vehicle occupants. Thus, the airflow device 10 may be positioned so that it interferes with neither the aesthetics or functionality of vehicle components and features. 13 03 25 Moreover, providing flows of air across surfaces of vehicle components may permit efficient heating and / or cooling of vehicle occupants. Such heating and / or cooling avoids the requirement of conventional seat heating / cooling arrangements that rely on heating / cooling of the seat pad (and therefore requires comparatively more energy) and avoids heating a large volume of air in the 5 vehicle cabin (again requiring comparatively more energy) as occurs with traditional vehicle HVAC systems. Embodiments of the present invention, may provide an alternative heating / cooling system for vehicle occupants, or it may supplement one or more other heating / cooling systems. Whilst at least some of the above described embodiments relate to arrangements in which the non-planar surface 63 is a surface 10 of a vehicle seat (which may be a front or rear vehicle seat), in other embodiments the non-planar surface 63 may be a surface of any vehicle component. Examples of such vehicle components include but are not limited to B, C or D posts, a cantrail, a facia, a centre console or a headliner. Figures 13 to 16 each show a surface 70 of a vehicle component in accordance with an embodiment of the present invention. The 15 surface 70 comprises a plurality of depressions 72 formed therein and arranged to manipulate attachment or detachment of a flow of air directed substantially parallel to or towards a portion of the surface. Indeed, it is found that providing a surface with a plurality of depressions 72 can impact how the Coanda effect is exhibited. Furthermore, the configuration and relative arrangement of the plurality of depressions may enhance or diminish the adhesion of the flow of air along the surface 70. 20 In certain embodiments, the surface 70 comprising the plurality of depressions 72 may be non-planar and may form the non-planar surface 63 described above. That is, the surface 70 comprising the plurality of depressions described herein may be employed in any embodiment that includes the non-planar surface 63 described above. By manipulating the attachment or detachment of the flow of air, the plurality of depressions 72 may cause the flow of air to follow contours of the non-planar surface. In substantially planar surfaces, the plurality of depressions may be utilised to maximise adhesion of the flow of air over the surface. Conversely, 25 the plurality of depressions 72 may be configured in a particular region of the surface to encourage detachment of the flow if air from the surface. In certain embodiments, the plurality of depressions 72 may be uniformly distributed. Such an arrangement is illustrated in each of Figures 13,14 and 15. 30 Each of the plurality of depressions 72 may be disposed on a vertex of a tessellating polygon. In Figures 13,14 and 15, the broken lines depict sides of the tessellating polygons. In Figure 13, the tessellating polygons comprise tessellating quadrilaterals in the form of parallelograms. Other possible 35 quadrilaterals include squares, rectangles and rhombuses. In the arrangement shown in Figure 13, the spacing between adjacent depressions 72 is less than the diameter of each depression 72. In contrast, in the arrangement shown in Figure 14, the spacing between adjacent depressions 72 is greater than the diameter (or width) of each depression 72. In the arrangement shown in Figure 14, each of the plurality of depressions 72 is disposed on a 40 vertex of a tessellating quadrilateral (parallelogram), although the vertices also correspond to vertices of tessellating triangles, which are shown in Figure 14 as broken lines. Indeed, in other embodiments, the tessellating polygons may be any suitable single or group of differing tessellating polygons including but not limited to hexagons, octagons, and dodecagons. 13 03 25 In certain embodiments, all of the plurality of depressions 72 may be identical to one another (as shown in the arrangements of Figures 13 and 14). In other embodiments, such as the arrangement shown in Figure 15, the plurality of depressions 72 are not identical to one another. In the arrangement shown in Figure 15, the plurality of depressions 72 include a first set of depressions 5 72a of a first type and a second set of depressions 72b of a second, different type. In the non-limiting example shown in Figure 15, the first set of depressions 72a each have a circular profile whilst the second set of depressions 72b each have a hexagonal profile. In other embodiments, any number of differing sets of depressions may be present, and the profile of each set is not limited to any particular shape or profile. 10 In certain embodiments, successive spacings between adjacent ones of the plurality of depressions 72 increase in at least one direction along the surface 70. Additionally or alternatively, successive spacings between adjacent ones of the plurality of depressions 72 decrease in at least one direction along the surface 70. As an illustrative example, in the arrangement shown in Figure 16, the successive spacings d1, d2, d3, d4 between adjacent ones of the plurality of depressions 72 decrease in a direction D1 along the surface 70. Viewed another way, the successive spacings d4, d3, d2, d1 between adjacent ones of the plurality of 15 depressions 72 increase in a direction D2 along the surface 70. The 3D form of the depressions 72 is not limited to any particular shape. In certain embodiments, at least some of the plurality of depressions 72 may each be formed as a portion of a sphere or a polyhedron (e.g. a dodecahedron). 20 The surface 70 of the plurality of depressions 72 may comprise any suitable material and may be determined by the structural and / or aesthetic requirements of the vehicle component of which it forms a part. In certain embodiments, the surface 70 may comprise a polymeric material (e.g. such as that that is typically used for a vehicle seat trim). Some or each of the plurality of depressions may have a depth (i.e. into the surface) of between 0.1 and 2 mm and optionally 25 between 0.2 mm and 1.5 mm. Additionally or alternatively, some or each of the plurality of depressions may have a width (e.g. the diameter in the case of circular depressions) between 1 mm and 5 mm, and optionally between 2 mm and 4 mm. Additionally or alternatively, the spacing between some or each of the plurality of depressions may be between 0.5 mm and 5 mm, and optionally between 1 mm and 4 mm. 30 The plurality of depressions 72 may be formed in the surface 70 by any suitable process. In certain embodiments, the plurality of depressions 72 may be formed in the surface 70 after formation of the surface 70 (e.g. in certain embodiments, the plurality of depressions 72 may be embossed into the surface 70). In other embodiments, the plurality of depressions 72 may be formed in the surface 70 during the process of forming the surface 70. In certain embodiments, the plurality of depressions 72 may be embossed into the surface 70. 35 It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application. 13 03 25

Claims

1. A vehicle sub-assembly comprising an airflow device and a seat having a surface, the surface comprising a plurality of uniformly distributed depressions formed therein and arranged to manipulate attachment or detachment of a flow of air directed substantially parallel to or towards a portion of the surface from an outlet of the airflow device,5 wherein each of the plurality of depressions is disposed on a vertex of a tessellating polygon.

2. A vehicle sub-assembly according to claim 1, wherein the surface is a non-planar surface and the plurality of depressions is arranged to cause the flow of air to follow contours of the surface.10 3. A vehicle sub-assembly according to any preceding claim, wherein spacings between adjacent ones of the plurality ofdepressions are each between 0.5 mm and 5 mm, and optionally between 1 mm and 4 mm.

4. A vehicle sub-assembly according to any preceding claim, wherein each of the plurality of depressions has a width between 1 mm and 5 mm, and optionally between 2 mm and 4 mm.

5. A vehicle sub-assembly according to any preceding claim, wherein each of the plurality of depressions has a depth between 0.1 mm and 2 mm, and optionally between 0.2 mm and 1.5 mm.

6. A vehicle sub-assembly according to any preceding claim, wherein at least some of the plurality of depressions are each formed 20 as a portion of a sphere or a polyhedron.

7. A vehicle sub-assembly according to claim 6, wherein all of the plurality of depressions are identical to one another.

8. A vehicle sub-assembly according to any of claims 1 to 9, wherein the plurality of depressions comprise dissimilar depressions.

259. A vehicle sub-assembly according to any preceding claim, wherein the surface comprises a polymeric material.

10. A vehicle sub-assembly according to any preceding claim, wherein the plurality of depressions are embossed into the surface.30 11. A vehicle comprising a vehicle sub-assembly according to any preceding claim.

Images