GB2594277A

GB2594277A - Drag reduction

Info

Publication number: GB2594277A
Application number: GB2005801.2A
Authority: GB
Inventors: Paul Ashtyn Smith Nigel
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-21
Filing date: 2020-04-21
Publication date: 2021-10-27
Anticipated expiration: 2040-04-21
Also published as: GB2594277B; GB202005801D0

Abstract

A rotor system 10 for a vehicle 5 has at least two rotor axles 21 on side supports 50, about which rotate rotor vanes 30, which may be semi-circular or helical, in a direction of circulating airflow 40, 42 of rotor system 10. An axis of rotation of each rotor axle 21 is orientable horizontally and perpendicular to advancing airflow over vehicle 5 during forward motion. Rotor axles 21 are tiered and their axes of rotation are parallel. Rotor system 10 also has front and rear cowlings 52, 54 which direct air to circulate around obverse and reverse sides of rotor system 10. Rotor axles 21 may be connected to a generator. Each rotor axle 21 may have a plurality of vanes 30. Also claimed is a vehicle 5 with rotor system 10, which may be for land, air or water transport.

Description

DRAG REDUCTION

Field of the Invention

The present invention relates generally to a rotor system for a vehicle exterior, especially to a drag reduction system for a vehicle, and to a vehicle comprising the rotor system.

Background of the Invention

There is an increasing requirement to improve the efficiency of vehicles, both for internal combustion engine (ICE) cars, and electric, or alternative fuel vehicles. Drag reduction features on vehicles mainly comprise alterations to the shape of the vehicle body or parts of the vehicle so as to create a streamlined vehicle. Beyond alterations to the vehicle made at the manufacturing stage, very few significant alterations can be made to the vehicle to reduce the drag. Formula V" vehicles have drag reduction systems that provide a driver-adjustable section of the rear wing that moves in response to driver commands to reduce the drag, but at the cost of also reducing the downforce. This system is only activated temporarily when additional speed is required for overtaking. Further, the slipstream is normally only useable by very skilled racing drivers, because it only works well when the vehicle that is to take advantage of the drag reduction system is very close to the vehicle it is following; to utilise the slipstream, the vehicle behind must be as close as possible to the vehicle ahead to obtain enough speed for overtaking, this is very dangerous and not usable under normal driving conditions. Hence, this type of system does not seem easily implemented on domestic and commercial vehicles, in which drag reduction is a constant requirement to improve overall fuel efficiency and safety on the road is an overarching principle.

Turbines can also be placed on vehicles to generate electricity from the air moving over the vehicle. While this electricity can be used to power certain systems within the vehicle, or recharge an electric vehicle battery, turbines have to be placed in a position in which the air is flowing over the vehicle, and therefore the drag coefficient of the vehicle is greatly increased. More power is required to drive the vehicle, therefore not improving the overall vehicle efficiency.

There is therefore a requirement for an improved drag reduction system and turbine system for vehicles that improve the overall vehicle efficiency, without increasing the overall drag on the vehicle. The present invention seeks to provide an improved drag reduction turbine system.

Summary of the Invention

According to a first aspect, there is provided a rotor system comprising: at least two rotor axles, the rotor axles rotatably mounted on side supports, a plurality of rotor vanes for rotation about the rotor axles, in a direction of circulating airflow of the rotor system, each rotor axle having an axis of rotation, the axis of rotation orientatable horizontally and perpendicular to an advancing airflow over the vehicle during forward motion of the vehicle, wherein the rotor axles are arranged in a tiered configuration in which the axes of rotation of the rotor axles are parallel; a front cowling; and a rear cowling disposed downstream of the front cowling; in which, in use, the advancing airflow causes rotation IS of the rotor vanes, a portion of the advancing airflow along an obverse side of the rotor being directed at a downstream end by the rear cowling to flow in a reverse direction along a reverse side of the rotor system, resulting in a reverse airflow, the reverse airflow being directed at an upstream end by the front cowling to re-join the advancing airflow along the obverse side of the rotor system, whereby a constant recirculating airflow is formed around the rotor system, for reducing drag.

The returning airflow may follow a path defined between the vanes and a base surface, the base surface provided by one of: a surface of the vehicle, a surface of a base element of the rotor system.

At least one rotor axle may be operatively connected to at least one generator.

The rotor vanes may form a Savonius turbine.

The rotor vanes may be semi-circular in section. The rotor vanes may be helical.

Each successive rotor axle may be allowed to rotate faster than the previous rotor.

Each rotor axle may be provided with a respective plurality of rotor vanes.

The rotor vanes may follow a circular rotational path, and the highest point in a vertical direction of the circular rotational path of each successive rotor is higher than the rotor axis of each successive rotor.

The rotor vanes may follow a circular rotational path, and the lowest point in a vertical direction of the circular rotational path of each successive rotor is lower than the rotor axis of each successive rotor.

The rotor vanes may be evenly circumferentially arranged about the axis of the respective rotor.

According to a second aspect, there is provided a vehicle comprising a rotor system, the IS rotor system according to the first aspect.

The vehicle may be capable of land transportation.

The vehicle may be capable of air transportation.

The vehicle may be capable of water transportation.

Further particular and preferred aspects of the invention are set out below.

Brief Description of the Drawings

The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure I shows a schematic diagram of the rotor assembly.

Figure 2 shows the rotor assembly.

Figure 3 is a front view of the rotor assembly on a vehicle.

Figure 4 is a front and side view of the rotor assembly on a vehicle.

Figure 5 is an alternative embodiment having 4 rotor vanes shown on a vehicle.

Figure 6 is an alternative embodiment having 6 rotor vanes.

Figure 7 shows an alternative rotor arrangement.

Figure 8 shows a feature of a rotor assembly mounted to a vehicle.

Figure 9 is a schematic of another rotor assembly, on a vehicle.

Description

The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein.

Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed.

IS On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

In the following description, all orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealised or overly formal sense unless expressly so defined herein.

Referring now to the drawings, wherein like reference numbers are used to designate like elements throughout the various views, several embodiments of the present invention are further described. The figures are not necessarily drawn to scale, and in some instances the drawings may have been exaggerated or simplified for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations of the present invention based on the following examples of possible embodiments of the present invention.

A rotor system for a vehicle is disclosed herein that comprises at least two rotor axles mounted on side supports, a plurality of rotor vanes for rotation about the rotor axles, in a direction of circulating airflow of the rotor system. An axis of rotation of each rotor axle is orientatable horizontally and perpendicular to an advancing airflow over the vehicle during forward motion of the vehicle, and the rotor axles are arranged in a tiered configuration in which the axes of rotation of the rotor axles are parallel. The rotor system further comprises a front cowling and a rear cowling disposed downstream thereof. The advancing airflow causes rotation of the rotor vane, and the front and rear cowlings direct air to circulate around obverse and reverse sides of the rotor system.

A rotor system is shown in Figure I. The rotor system 10 is shown on the front of a vehicle 5. The rotor system comprises a series of rotors 20, each comprising a rotor axle 21 and a plurality of rotor vanes 30, each rotor rotating around its own horizontal axis 22. Each axis is arranged substantially horizontally with respect to the ground on which the vehicle travels. The rotors 20 are arranged such that the axes 22 are parallel and stepped, to form a tiered arrangement of rotors. Each rotor is arranged vertically higher than and downstream of the previous rotor, where the vertical direction is vertical relative to the plane of the ground on which the vehicle travels. In this embodiment, the rotor system 10 has six rotors, each with two vanes 32, 34. The rotors are arranged so that the horizontal axis is not vertically above the maximum vertical extent of the advancing vane of the previous rotor. This ensures only the advancing vanes 32 are open to the airflow, creating less air resistance on the returning vanes 34.

Once the vehicle is in motion, moving in a forward direction, air flows over the vehicle body, in an advancing airflow direction. This advancing airflow interacts with the vanes 30 of each rotor, causing rotation of each rotor. The front cowling 52 ensures airflow is directed over only the advancing vane 32 of the upstream rotor 24. A rear cowling 54 is placed downstream of the downstream rotor 26 to direct a portion of the advancing airflow back along a base surface 56 to cause a reverse airflow over the returning vanes 34 of each rotor. When the reverse airflow reaches the upstream rotor 24 and the front cowling 52, the airflow is redirected to join the advancing airflow, therefore increasing the air speed over the rotor assembly, and decreasing the drag of the vehicle. Each rotor 20 is additionally driven by the reverse airflow acting on the returning vanes 34, which increases the rotational speed of the rotors 20, therefore allowing air to pass over the rotor system 10 more quickly. This reduces the air resistance of the vehicle 5.

The reverse airflow is parallel and opposite in direction to the advancing airflow, both of which are parallel to a plane 28 on which all the rotor axes are aligned. The plane 28 being at an inclined angle with respect to the horizontal to provide the tiered arrangement of the rotors.

Each of the vanes 30 rotates in a direction of circulating airflow of the rotor system, which is indicated by arrow 40 (advancing airflow direction along obverse side of rotor system) and arrow 42 (reverse airflow direction along reverse side of rotor system).

IS

The rotors 20 are rotatably mounted on side supports 50, as shown by Figure 2. These side supports, along with the base surface 56 provide a channel for the returning airflow to ensure all the reverse airflow acts on the returning vanes 34. The front views provided in Figure 3 and Figure 4 shows the parallel arrangement of the rotors 20 on the front of the vehicle 5.

The base surface 56 may be provided by a surface of the vehicle 5 or by a base element of the rotor system 10.

Figure 5 shows an alternative embodiment of the invention in which the rotors 120 each have four vanes. The embodiment of Figure 6 has six vanes per rotor 220. The rotor may have any number of vanes. The shape of the vanes may vary, having straight, curved, semi-circular sections or similar, and the rotors may also be helical.

The rotors may also be arranged on the vehicle 305 of Figure 7 such that the advancing airflow is directed in a downward direction toward the underside of the vehicle 305. The rotors 320 are arranged such that each successive rotor is arranged vertically lower than and downstream of the previous rotor. A front cowling 352 ensures the air flows over only the advancing vane of the upstream rotor, and the rear cowling 354 directs a portion of the advancing airflow in a reverse direction along the returning vanes.

Comparing the relative orientation of the rotor assembly to the vehicle that is shown in Figure 7 with the relative orientation of the rotor assembly to the vehicle that is shown in Figure 5, the arrangement of Figure 7 is associated with reduced lift, and hence improved downforce, when compared to the arrangement of Figure 5.

In an embodiment, the rotors are operatively connected to at least one generator.

Electricity generated by the at least one generator may be stored using any suitable type of electricity storage, for example a battery unit. Electricity generated during use of the rotor system may be utilised in running the vehicle, for example, generated power may be used for propelling the vehicle or for one or more peripheral system functions of the vehicle. Thus, not only can the rotor system described herein serve to reduce fuel efficiency by a vehicle through reducing drag but can also serve to reduce refuelling need through generating electricity that can be used by the vehicle.

Figure 8 illustrates a rotor system 810 mounted to a vehicle 805, with the rotor 820 closest to the front wheels 880 of the vehicle 805 coupled in rotation with a generator, indicated at 881, by a pulley 882.

Figure 9 shows another rotor assembly 910, on a vehicle 905. As illustrated, a series of vanes, such as vane 920, is secured to a belt 982 that is rotatable about a spaced apart pair of rotor axles 983, 984. In the shown example, the vanes are all the same type and size and are distributed evenly around an outer surface of the belt As also shown in this example, rotor axle 984 is positioned vertically higher than and downstream of the rotor axle 983, where the vertical direction is vertical relative to the plane of the ground on which the vehicle 905 travels. As the vehicle 905 moves forward, in the direction indicated by arrow 985, an advancing air flow impinges on the rotor assembly 910 in the opposite direction, indicated by arrow 986, which causes the vanes 920 to rotate in a direction of circulating airflow of the rotor system 910 indicated by arrow 987. The vane 920, which is shown on an obverse side 988 of the rotor assembly 910, travels in the direction of rotation 987 until it travels around rotor axle 983, as indicated by arrow 989, to a reverse side 990 of the rotor assembly 910, whereafter it continues to travel in the direction of rotation 987 until it travels around the other rotor axle 984, as indicated by arrow 991, back to the obverse side 988 of the rotor assembly 910.

By reversing the airflow along the obverse side to the reverse side of the rotor assembly, the vanes are driven on both sides of the rotor assembly at once, making the rotor assembly highly efficient Rather than being a perpetual motion device; the rotor assembly reclaims some of the power otherwise lost by pushing an object through air at speed. By reversing the airflow in front of vehicles, a component of the energy can be converted to power, with more power able to be generated with more speed.

The rotor assembly described herein creates a slipstream that reduces air drag; this can reduce the fuel consumption/extend the mileage of any vehicle, including vehicles with internal combustion engines and electric powered vehicles.

IS

The rotor assembly disclosed herein reverses the air drag in front of a vehicle, allowing it to slip through the air with less friction. The vanes act like wheels on air drag, creating a slipstream before the vehicle. The main force of resistance (air drag) can be be converted to power by connecting at least one axle of the vanes to a generator. It is to be appreciated that one axle could be connected to two generators (each end of the operatively connected to a respective generator) so, for example, six vanes could power twelve generators, which could provide power to twelve batteries, which may be sufficient to run a car. Larger vehicles, such as busses and lorries, which have larger faces/drag areas, can be provided with more vanes, to give more power.

The effect of the movement of the rotors through the air can be seen to create a slipstream over the front of the vehicle, due to the effect of the already moving air from the rotors being re-directed over the front of the vehicle. As the slipstream is created at the front portion of the vehicle, the air passing over the remainder of the vehicle is already travelling at speed, reducing the drag. The rotation of the rotors allows the drag on the vehicle to be converted to electricity using generators. In reversing the airflow, the vanes are driven by both the advancing airflow and the returning airflow, allowing greater power generation. On an average car, 12kVV of power could be reclaimed when travelling at 60mph. The rotors may be arranged from the bumper to the windscreen on a conventional vehicle.

The rotor system can be seen as analogous to a conveyor belt, where the advancing airflow travels in one direction over the top of the conveyor belt, and the returning airflow travels along the bottom of the conveyor belt However, it is to be understood that the vanes may rotate in the direction of circulating airflow either by rotating around the axis of one of a plurality of rotor axles or by together traveling a path around a plurality of rotor axles.

It is to be appreciated that a rotor system as described herein may have any suitable alternative number of rotors, and may have the same or any suitable alternative type of vanes. It is to be appreciated that the rotor system may include vanes of more than one type. A rotor system as described herein may have any suitable dimensions and appearance, and may be fabricated from any suitable material or materials and may be manufactured using any suitable process or processes.

The rotor system described herein may be used on any suitable vehicle, which may be a commercial or non-commercial vehicle, and which may be capable of one or more of land transportation, air transportation and water transportation, such as: a car, a lorry, a bus, a train, an aircraft.

The rotor system described herein may be used in any of a variety of industrial fields, including aviation and aerospace.

The apparatus disclosed herein may be termed a self-inducing slipstream device, a regenerative slipstream device, an air-drag reduction by reverse airflow device, or a self-sustaining slipstream range extender.

A rotor system for a vehicle is disclosed herein that comprises at least two rotor axles mounted on side supports, a plurality of rotor vanes for rotation about the rotor axles, in a direction of circulating airflow of the rotor system. An axis of rotation of each rotor l0 axle is orientatable horizontally and perpendicular to an advancing airflow over the vehicle during forward motion of the vehicle, and the rotor axles are arranged in a tiered configuration in which the axes of rotation of the rotor axles are parallel. The rotor system further comprises a front cowling and a rear cowling disposed downstream thereof. The advancing airflow causes rotation of the rotor vane, and the front and rear cowlings direct air to circulate around obverse and reverse sides of the rotor system.

Although illustrative embodiments and examples of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiment and examples shown and/or described and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

Claims I. A rotor system for a vehicle, comprising: at least two rotor axles, the rotor axles rotatably mounted on side supports, a plurality of rotor vanes for rotation about the rotor axles, in a direction of circulating airflow of the rotor system, each rotor axle having an axis of rotation, the axis of rotation orientatable horizontally and perpendicular to an advancing airflow over the vehicle during forward motion of the vehicle, wherein the rotor axles are arranged in a tiered configuration in which the axes of rotation of the rotor axles are parallel; a front cowling; and a rear cowling disposed downstream of the front cowling; in which, in use, the advancing airflow causes rotation of the rotor vanes, a portion of the advancing airflow along an obverse side of the rotor being directed at a downstream IS end by the rear cowling to flow in a reverse direction along a reverse side of the rotor system, resulting in a reverse airflow, the reverse airflow being directed at an upstream end by the front cowling to re-join the advancing airflow along the obverse side of the rotor system, whereby a constant recirculating airflow is formed around the rotor system, for reducing drag.
2. A rotor system as claimed in claim I, in which the returning airflow follows a path defined between the vanes and a base surface, the base surface provided by one of: a surface of the vehicle, a surface of a base element of the rotor system.
3. A rotor system as claimed in claim I or claim 2, in which at least one rotor axle is operatively connected to at least one generator.
4. A rotor system as claimed in any preceding claim, in which the rotor vanes form a Savonius turbine.
5. A rotor system as claimed in any preceding claim, in which the rotor vanes are semi-circular in section.
6. A rotor system as claimed in any of claims 1 to 4, in which the rotor vanes are helical.
7. A rotor system as claimed in any preceding claim, in which each successive rotor axle is allowed to rotate faster than the previous rotor.
8. A rotor system as claimed in any of claims 1 to 7, in which each rotor axle is provided with a respective plurality of rotor vanes.
9. A rotor system as claimed in claim 8, in which the rotor vanes follow a circular rotational path, and the highest point in a vertical direction of the circular rotational path of each successive rotor is higher than the rotor axis of each successive rotor.
10. A rotor system as claimed in claim 8, in which the rotor vanes follow a circular rotational path, and the lowest point in a vertical direction of the circular rotational path of each successive rotor is lower than the rotor axis of each successive rotor.
1 I. A rotor system as claimed in any of claims 8 to 10, in which the rotor vanes are evenly circumferentially arranged about the axis of the respective rotor.
12. A vehicle comprising a rotor system, the rotor system as claimed in any of claims 1 to II.
13. A vehicle as claimed in claim 12, wherein the vehicle is capable of land transportation.
14. A vehicle as claimed in claim 12, wherein the vehicle is capable of air transportation.
15. A vehicle as claimed in claim 12, wherein the vehicle is capable of water transportation.