Aspects of the present disclosure relates to modifying aerodynamic performance of a vehicle. Aspects of the disclosure also relate to a bonnet for a vehicle and to a control unit.
Aerodynamics plays a key role in the design of vehicles, such as motor or road vehicles (vehicles, vans, trucks, etc.). Particular attention is paid to the aerodynamic drag force, as it directly affects fuel consumption and greenhouse gas emissions (notably CO2). Various vehicle components are accordingly designed so as to optimize the aerodynamic performance of a vehicle.
For example, spoilers (i.e. devices positioned at specific locations about a vehicle, such as at the rear of a vehicle, on top of the boot or roof of the vehicle, and/or at the front bumper of the vehicle) are common place and can be used to channel air flow around and/or into a vehicle as well as reduce the aerodynamic lift force, or even generate a negative (downwards) force (which may aid vehicle stability and handling, particularly at high speeds and/or during cornering). The spoilers can act to effectively reduce unsteady air movement (such as turbulence) across the body of the vehicle when in motion and by doing so, improve aerodynamic performance.
It is an aim of the present invention to improve aerodynamic performance of a vehicle.
Aspects of the invention relate to a bonnet for a vehicle having a bypass duct; and to a vehicle having a bonnet incorporating a bypass duct, and to a control unit for a vehicle.
According to another aspect of the present invention, there is provided a bonnet for a vehicle, the bonnet comprising: a front edge and a rear edge; a recessed longitudinal channel being formed in said bonnet and extending from said front edge towards the rear edge; and an airflow modification device disposed transversely across the longitudinal channel for controlling airflow over the bonnet, wherein the airflow modification device and the recessed channel form a conduit, the conduit having a cross-sectional area which is diverging as the conduit extends towards the rear edge. The recessed longitudinal channel thereby forms a duct for taking air from the front of the vehicle, below the bonnet line, and passing it internally behind the airflow modification device and venting it onto a surface of the bonnet. The recessed longitudinal channel thereby forms a bypass vent. The airflow modification device can define a bonnet leading edge.
According to a further aspect of the present invention, there is provided a bonnet for a vehicle, the bonnet comprising:
a front edge and a rear edge;
a recessed longitudinal channel being formed in said bonnet and extending from said front edge towards the rear edge; and
an airflow modification device disposed transversely across the longitudinal channel for controlling airflow over the bonnet, wherein the airflow modification device and the recessed channel form a conduit having a cross-sectional area, and wherein a flap and/or the airflow modification device and/or at least a portion of the bonnet is movable to change the cross-sectional area. Advantageously, a movable element of the bonnet arrangement, whether that be a flap disposed on the bonnet/member itself, and/or the airflow modification device, and/or the bonnet itself, can be moved in order to change the cross-sectional area.
The flap and/or the airflow modification device and/or at least a portion of the bonnet may be movable by one or more actuators to change the cross-sectional area.
The flap and/or the airflow modification device and/or at least a portion of the bonnet may be movable between an un-deployed configuration and at least one deployed configuration. In the un-deployed configuration or in a deployed configuration the cross-sectional area may be diverging as the conduit extends towards the rear edge.
The airflow modification device therefore causes airflow at a front side of the vehicle (in particular, when the vehicle is travelling) to be substantially directed along the recessed longitudinal channel so that the airflow can be controlled over the bonnet. This controlling of airflow reduces the size of the zone of high pressure which forms on the front of a moving vehicle and also reduces the losses associated with airflow over the bonnet leading edge, resulting in a reduced aerodynamic drag force. At least in certain embodiments, the recessed longitudinal channel can provide a more aerodynamically efficient flow path for air that would have been forced to flow over the bonnet leading edge. The recessed longitudinal channel has an inlet which can be disposed above a front stagnation zone and below the airflow modification device. An internal flow path ducts the flow under the airflow modification device and vents it onto the bonnet surface. The recessed longitudinal channel may be formed by the bonnet surface and the airflow modification device. In an alternative arrangement, a bypass duct may be formed by a structure, such as a channel or conduit, which sits below the bonnet. The side profile of the vehicle may be aesthetically, rather than aerodynamically optimized.
The longitudinal channel may have a front section and a rear section; wherein the airflow modification device may be disposed transversely across said front section of the longitudinal channel. The airflow modification device is thus positioned towards the front of the vehicle bonnet so as to modify airflow prior to the airflow travelling along the bonnet. The front section of the longitudinal channel can be oriented to direct airflow upwardly. In certain embodiments, the airflow modification device can be inclined such that the incident airflow is directed towards the top of the vehicle windscreen or over the roof of the vehicle.
The said front section may comprise a substantially continuous surface for guiding airflow over the bonnet. The substantially continuous surface means that the surface is devoid of any apertures or air inlets and thus the airflow is controlled over and around the bonnet as opposed to flowing into the engine bay.
The bonnet may comprise left and right side portions which define the respective sides of the bonnet. The left and right side portions of the bonnet can define the lateral sidewalls of the longitudinal channel. The airflow modification device can extend between said left and right side portions.
The airflow modification device and the recessed channel can form a conduit which is open at each end to form an inlet and an outlet. The inlet is open towards the front of the vehicle so that air is entrained into the conduit when the vehicle is travelling in a forwards direction. The conduit can have a cross-sectional area which is substantially constant, converging or diverging as it extends towards the rear of the bonnet. As such, the conduit may act accelerate or decelerate the airflow over the bonnet surface.
The airflow modification device may comprise one or more flaps. The flaps can be either fixed at a predefined angle relative to a horizontal plane, or being movable relative to a horizontal plane. The movable flaps can therefore act to change how the airflow moves over and around the bonnet, therefore changing the aerodynamic efficiency of the vehicle.
The airflow modification device can comprise an aerofoil.
The bonnet can comprise a hinge element.
According to a further aspect of the present invention, there is provided a control unit for a vehicle, configured to transmit a control signal to cause, at least in part, the movement of the flap and/or the airflow modification device and/or the at least a portion of the bonnet as described herein.
According to a further aspect of the present invention there is provided a vehicle comprising the bonnet as described herein.
According to some, but not necessarily all examples there is provided a bonnet for a vehicle, the bonnet comprising: a front edge and a rear edge; a recessed longitudinal channel being formed in said bonnet and extending from said front edge towards the rear edge; and an airflow modification device disposed transversely across the longitudinal channel for controlling airflow over the bonnet.
Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.
One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
A vehicle 1 comprising a deployable closure panel 3 for an air inlet 5 of the vehicle 1 is illustrated in
In more detail,
The closure panel 3 is shown by a dashed line to indicate that it is hidden from view beneath the bonnet 9. In particular, the closure panel 3 is located in a retracted position within the vehicle 1, whereby it is spaced at a distance away from the air inlet 5 so that it does not interrupt airflow via the air inlet 5 to the engine bay. The closure panel 3 is sized and shaped so that it can close the air inlet 5 to inhibit, reduce or otherwise substantially prevent airflow via the air inlet 5 to the engine bay. The closure panel 3 thus comprises a continuous (uninterrupted) outer surface 11 so that air cannot pass through the closure panel 3. The outer surface 11 is front facing in the present embodiment. In this example, the opening defining the air inlet 5 is substantially elliptical. Accordingly, the closure panel 3 has a substantially elliptical shape so that the outside edges of the closure panel locate proximal to (or abut against) the inner edges of the air inlet 5 when the closure panel 3 is positioned within the air inlet 5.
In operation, the closure panel 3 is moved between the retracted position (shown in
The operation of the closure panel 3 will now be described in more detail with reference to
A control system 50 is provided within the vehicle 1 for controlling deployment of the closure panel 3. The control system 50 comprises a control means 55, an actuation means and a mechanical assembly 65. The control means 55 may be a control module of a vehicle (not shown), a computer, a processing module, and so forth. As such, the control means 55 may comprise one or more processors, one or more memories and/or logic circuitry and may be capable of executing computer program code. The actuation means is in communication with the control means 55 and may be any form of actuator 60 suitable for moving the closure panel 3 into one of a deployed position and a retracted position. The actuator 60 may, for example, comprising a pneumatic piston, an hydraulic piston, an electric motor, and so forth. The mechanical assembly 65 is in communication with the actuator 60 and accommodates the deployment and retraction of the closure panel 3 in the different positions. Accordingly, the mechanical assembly 65 may comprise devices to enable the necessary rotation and/or translation of the closure panel 3.
The actuator 60 receives a control signal from the control means 55 to deploy the closure panel 3 to the deployed position. At least in certain embodiments, the control means 55 can be configured to deploy the closure panel 3 progressively to control the proportion of the air inlet 5 which is closed. Responsive to, or based on the control signal received from the control means 55, the actuator 60 causes the mechanical assembly 65 to move the closure panel 3 to the deployed position so that the closure panel 303 effectively seals or closes the air inlet 5. At any point thereafter, the actuator 60 may receive a subsequent control signal indicating that the closure panel 3 should be retracted from the air inlet 5 and accordingly instructs the mechanical assembly 65 to move the closure panel 3 to its retracted position away from the air inlet 5.
In the example of
In the illustrated arrangement of
The operation of the closure panel 103 is similar to that described above with reference to
Embodiments of the present invention as described herein refer to various air inlets 5; 105, which may be opened or closed using various closure panels 3; 103 so as to modify aerodynamic efficiency. Whilst some air inlets may be specifically designed to control aerodynamic efficiency, many of the air inlets 5; 105 may be designed to enable airflow to cool one or more internal components of a vehicle and consequently may be referred to as “cooling air inlets”.
It will be appreciated that, whilst embodiments of the present invention have been described with reference to the examples described above, various modifications and alternatives will be apparent. For example, in the above examples described with reference to
The external surface of the vehicle 1; 101 is typically painted. The continuous outer surface 11; 111 of the closure panel 3; 103 may have a painted finish which matches, or contrasts with, the painted external surface of the vehicle 1; 101.
Although the above examples described with reference to
Embodiments of the present invention also relate to using an airflow modification device in the form of an aerofoil 201 (airfoil) to control air flow around a motor vehicle such as the motor vehicles 1; 101 depicted in
The bonnet 203 may comprise a hinge element, such as a hinge or a connector to connect to a hinge, for connection to the vehicle.
The recessed channel 205 is formed such that the recess has a maximum depth at the front edge 207 of the bonnet 203 and decreases in height extends towards the rear edge 209 of the bonnet 203. First and second side portions 215, 217 are thereby formed on either side of the channel 205.
The channel 205 comprises a guide surface 219 (i.e. the surface between the left and right side edges 211, 213). The guide surface 219 acts to direct air flow over the bonnet 203 and towards the top of the windscreen (not shown) of the vehicle as the vehicle is travelling in a forward direction. In the present embodiment the guide surface 219 is continuous and uninterrupted and is formed without air inlets or apertures.
An aerofoil 201 is disposed at the front of the bonnet 203 and extends transversely between the side portions 215, 217. More particularly, the aerofoil 201 is spaced above the guide surface 219 of the bonnet 203 at a predefined height so that there is a through-gap between the aerofoil 201 and the guide surface 219 of the bonnet 203, thereby forming a horizontal passage 221 to allow airflow through to the recessed channel 205. The aerofoil 201 is secured in position by the side portions 215, 217 via securing or fixing means (not shown). The aerofoil 201 is described in greater detail below with reference to
A first vertical separation distance is defined between the leading edge 229 and the guide surface 219 and a second vertical separation distance is defined between the trailing edge 231 and the guide surface 219. In the present embodiment, the lower surface 227 of the aerofoil 201 is arranged substantially parallel to the guide surface 219 such that the first and second vertical separation distances are substantially equal. In other examples, the second separation distance may be greater than the first separation distance so as to decelerate airflow over the guide surface 219. In other examples, the second separation distance may be smaller than the first separation distance so as to accelerate airflow over the guide surface 219. The aerofoil 201 and the recessed channel 205 can be viewed as forming a conduit which is open at each end (i.e. at the front and back). In a first configuration, the conduit can converge as it extends towards the rear of the bonnet. In a second configuration, the conduit can diverge as it extends towards the rear of the bonnet.
In the example described above with reference to
It will be appreciated that, whilst embodiments of the present invention have been described above with reference to
In the above examples described with reference to
It will be appreciated that the positioning of the aerofoil 201 along the bonnet 203 may vary according to characteristics and design of the relevant vehicle.
A further modification would be to dispose a control element 233, such as a flap or spoiler, on the aerofoil 201 or in the recessed channel 205 in the bonnet 203. By way of example, a control element 233 is shown in phantom in the schematic representation of the bonnet 203 shown in
In some, but not necessarily all examples, the aerofoil 201 and/or at least a portion of the bonnet 203 is movable in dependence on a control signal to change the cross-sectional area of the conduit.
It would be appreciated that any one of the first, second and third configurations could be defined as an un-deployed configuration, wherein at least one of the other configurations is defined as a deployed configuration. For example the aerofoil 201 may be movable between the configurations to modify front axle lift and/or balance duct inlet flow against cooling inlet flow into an inlet in a front bumper 7 of the vehicle 1, 101.
The vehicle may comprise control means. The type of control means is as described herein in relation to control means and control unit 55. The control means may be configured to transmit a control signal to cause one or more actuators to selectively deploy the control element 233 or the aerofoil 201 and/or the at least a portion of the bonnet 203 to change the cross-sectional area of the conduit. The type of actuators may be as described herein in relation to the actuators 60.
The control signal may be transmitted in dependence on at least one operating parameter of the vehicle 1, 101. Example operating parameters may include: the speed of the vehicle 1, 101; a selected predefined vehicle dynamic mode, for example a Track or Sport dynamic mode.
Various closure panels and aerofoils have been described herein. Such elements may be constructed using materials common to vehicle construction such as alloys, aluminum, plastics, fiberglass and other such composite materials.
The embodiment(s) described herein refer to a vehicle comprising two doors (excluding the tailgate or boot lid), but the vehicle could have a four door configuration (excluding the tailgate or boot). For example, the vehicle could be a saloon (sedan) or a sports utility vehicle. It will be appreciated that aspects of the present invention(s) could be applied to other vehicle configurations. For example, the vehicle could be an estate car (station wagon), hatch-back, coupe, off-road vehicle or a sports utility vehicle. Furthermore, the invention(s) described herein are not limited to motor vehicles. The vehicle can be an automobile, a truck, a lorry, an articulated vehicle and so on.
The present disclosure describes positioning adjacent panels to form a substantially continuous exterior surface. It will be appreciated that this is subject to usual manufacturing clearances and tolerances for exterior panels. A shut line (or cut line) is formed between adjacent panels where one (or both) of the panels is movable. The shut line comprises a clearance gap to accommodate relative movement of the panels. The outer surfaces of the panels on each side of the shut line are aligned with each other to form the substantially continuous exterior surface described herein. Thus, the composite exterior surface (defined by two or more panels) is substantially continuous insofar as it is free from steps or offsets at the interface between the panels. By way of example, the substantially continuous exterior surface can comprise a continuous curved surface (formed in 2-dimensions or 3-dimensions) and/or a continuous planar surface.
Number | Date | Country | Kind |
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1413849.9 | Aug 2014 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/068026 | 8/5/2015 | WO | 00 |