CA3060653A1 - Vehicle-mounted, flow-capture helical turbine (hawt) - Google Patents

Abstract

This patent relates to a new type of turbine blade, and the assembly for its intended use. Specifically, it describes a blade meant to be used as an attachment on a vehicle or other non-stationary object. The design of the device consists of two parts: the Drill and the Tunnel.
The Drill is a set of helical turbine blades on a shaft, designed to be installed with an orientation that is parallel to the fluid flow. The Tunnel is a cylindrical housing for the Drill, designed to capture fluid flow and force it along the blades. The intake and outlet of the Tunnel work in conjunction with the blades of the Drill to create a channel for fluid to pass through. The design is intended to be modular, allowing for multiple turbines to be attached in parallel.

Description

Vehicle-mounted, flow-capture helical turbine (HAWT) This patent relates to a new type of turbine blade, and the assembly for its intended use. Specifically, it describes a blade meant to be used as a mobile attachment on a vehicle or other non-stationary object.
Turbines are most often placed as stationary installations which take advantage of increased air velocity at high altitudes. As such, they are designed to be large or omni-directional and must be placed strategically to optimize their exposure to fluid flow.
Turbines use generators or alternators to convert mechanical energy into electrical energy. A commonly available generator used in standard turbines would require a rotational input between 1000 and 1800 RPM to produce a charge.
The large, three-bladed wind turbine used for industrial power production Is a Horizontal Axis Wind Turbine or HAWT. Turbines with this design are usually very large, reaching high enough into the sky to be affected by very high-speed winds that are not present at ground level on a regular basis. The high-speed winds on the furthest end of the very large blade generate a large amount of torque on the turbine's shaft. This torque can be transmitted to a much higher speed to generate a great deal of energy.
Along with the HAWT, there is another common type of turbine. This is the Vertical Axis Wind Turbine or VAWT. Helical turbines, usually VAWT's, are typically smaller and are designed with omnidirectional flow in mind. Unlike the larger HAWT's, which are erected in windy areas at great height for a dependable and predictable supply of air flow, smaller, helical VAWT's are made to produce energy indiscriminately whenever there is wind. While they are still installed at height, they do not guarantee a consistent supply of air flow like the larger HAWT's. Because these models are much smaller, they can be connected directly to their generator without being transmitted through a gearbox or some other means to convert the input torque into the appropriate speed. This is more efficient in theory, but without a consistent air flow, these VAWT's tend to produce much less energy.

Vehicles moving at high speeds do not face such problems as:
(1) variable wind direction, since the wind is always greatest coming from the direction of motion;

(2) unknown wind speed, since the vehicle's speed is determined by the driver;
and

(3) unknown duration of wind exposure, since the vehicle is exposed to wind whenever the vehicle is in motion.
The proposed design is built to be compact enough to fit into the body of a vehicle without greatly impacting its streamline. By orienting the intake to be parallel with the vehicle, it ensures that the wind direction is always lined up with the leading edge of the blade.
Optimizing the assembly for the vehicle's average sustained speed will also allow the turbine to charge whenever the vehicle is at its highest level of power consumption.
List of technical drawings [1] Drill turbine shaft and blades [2] Cylindrical "wind tunnel" shaft with nozzle intake [3] Full assembly of device (assembled view)

[4] Full assembly of device (exploded view)

[5] Assembly with minimum number of helix rotations

[6] Minimum rotations with four blades and shallower angle

[7] Excessively shallow helix angle

[8] Cross-section of nozzle intake

[9] Minimum helix rotations adjusted for choking

[10] Unobstructed airway with properly sized helix

[11] Modular assembly of multiple devices The design of the device will be outlined in three parts: the Dri11111, the Tunnel[2] and the Assemblyi3' 41 of both parts. This detailed description will use general terms to highlight the major design aspects of the device that would be necessary to recreate a functional version for any given vehicle. Specific references to dimensions, as they appear in the accompanying technical drawings, are based on a specific iteration of the design and should not be taken as the definitive dimensions of all possible versions.
Drill[1] ¨ Drill turbine or Drill refers to the entire part, including the shaft and helical blades This turbine blade[1], meant for constant unidirectional flow, is designed with a central shaft surrounded by two or more helical blades. In appearance, it resembles an auger or drill.
Additional helices will keep the leading edge as close as possible to the source of the fluid flow, but each helix also increases the mass of the blade. The shaft will be connected to an arbitrary turbine generator to produce energy[3]. Unlike most turbine blades, this device is intended for small scale use with a constant source of known direction. It may be used in air or in water.
Fluid medium and average sustained speed of the vehicle will determine the optimal number of blades and their angle, but special attention must be paid to the balance, length and durability of the Drill. Using more than one blade is necessary to counterbalance the rotation and minimize vibration in the shaft. Vibration is not only noisy, but decreases the life of the part. At up to 1800 RPM and over a life of upwards of one year of use, the part would be expected to survive tens of millions of rotations before failure.
The part could be engineered to last for the life of the vehicle, which would greatly increase the need to eliminate vibration. Minimizing length, increasing shaft diameter or using a more rigid material will also serve to eliminate vibration in the shaft.
However, both greater shaft diameter and denser material will increase the cost and mass of the part, which is meant to be as cheap and as light as possible without being prohibitively fragile.
The final design consideration is coverage of the intake. Ideally, some part of at least one blade should be in line with the intake at all times. To achieve this, each helix must be projected around the shaft no less than one time divided by the number of blades[5]. This means that a greater angle will greatly increase the length of the shaft. By decreasing the angle of the blade or increasing the number of blades, the length of the shaft can be decreased[6], with the additional benefit that the distance from the fluid intake is decreased as well.
However, both these options will add to the mass of the part, so a balance must be found between life of the part and energy losses.
It should also be noted that increasing the diameter of the blade will result in a shallower angle (less than 45 from perpendicularM). This means that the Drill will need to grow larger in proportion to the blade diameter to ensure a sufficient angle to generate torque.
Additionally, the inner thickness of the blade will also need to increase to compensate for the steeper angle at the shaft. This can be accomplished by increasing the thickness of the shaft or by altering the profile of the helix. This is not strictly a concern for the suggested design, but would be an issue for a larger scale of vehicle.
For these reasons, the suggested designm uses two blades with an exterior angle of 45 degrees. Variations for different vehicles may use anywhere between two and four blades, with angles ranging from 45 to 60 degrees from perpendicular.
Tunne1121¨ Wind tunnel or Tunnel refers to the cylinder in which the Drill is placed The helical shape of the blade is designed to continue being propelled by the fluid even after initial contact with the flow. However, losses are great after that point. To that end, the Drill turbine is meant to be placed inside of a specialized "wind tunnel" to capture and direct fluid flow along the length of the shaft. The intake of the Tunnel is a nozzle, aligned with the point furthest from the Drill shaft[3]. As the shaft rotates, the next helix blade moves into the flow. The lubricated cylinder has the same radius as the outer edge of the helix, trapping the fluid in the path created by the blades. As the fluid is drawn to the outlet, it continues to propel the Drill.
Due to the small scale of the device, it may be prohibitively expensive to machine the throat of the nozzle to a small enough diameter to be effective. For this reason, the nozzle may be as contoured or as straight as costs allow. The nozzle in the technical drawingsm is based on a generic nozzle design, but depending on the scale required by the vehicle, this may be a simple cylinder or even a semicircular opening.

The size and speed of the vehicle will dictate the scale of the device: larger vehicles allowing for larger Tunnels with more intricate nozzles, and higher speeds necessitating larger, more durable blades.
Assembly13, 41 The small scale of the device is compensated for by the high velocity of fluid flow, which is captured and directed by the nozzle. The shaft of the Drill is aligned with the flow131 and can be affected by the flow at all times. The Drill itself rotates inside the Tunnel, and is held in place by a bearing at either end. The Drill shaft drives the turbine generator after it passes outside of the Tunnel.
When installed, the assembly would likely be embedded into the walls of the vehicle, which would obstruct a portion of the outlet. To draw the air to the outlet and prevent choking, the helices and outlet must be aligned such that the path created between two adjacent blades- the path of the fluid from the intake to the outlet- is always clear.
This means that the length of the Drill shaft and Tunnel are dictated somewhat by the assembly.
This is to say that the number of rotations[9] of any given helix must be enough to reach back to the depth to which the assembly has been embedded into the vehicle; each helix that starts at the start point of the intake must end at or before the start point of the outlet[wl. If the design of the vehicle allows, the outlet should be oriented at the bottom of the Tunnel (taking the intake as the top), this will ensure the minimum number of helix rotations and may cut down the unsupported shaft length by as much as half[5].
In practice, two or more of these assemblies may be affixed to a vehicle in paralle1[11], above and/or below its body, and aligned with its direction of motion. The natural streamline along the vehicle will be captured and used to produce energy. In theory, the power generation would increase linearly with each additional turbine, and would only be limited by cost, space requirements and heat produced by the generators.
The assembly is designed to be modular to allow for multiple turbines in parallel, but its dimensions can be scaled to the outer dimensions of the Tunnel[3]. The Tunnel is a square prism with a length dictated by its depth into the body (number of rotations of a helix19. The square's side length is slightly thicker than the diameter of the Tunnel itself, which should be equal to the outermost diameter of the Drill blade. Assemblies on either end of a chain of parallel modules[111 may be rounded or otherwise contoured to remove the sharp corner of the square face.
The technical drawingol has a Drill diameter of 4 cm, with outer dimensions of the Tunnel measuring 5 cm by 5 cm by 15 cm. For much larger vehicles, or much higher fluid velocities, the Drill diameter may be scaled up to as much as 30 cm.
This blade is designed to be used to extend the battery life of electric cars, but could be also used to provide additional power to any electric charger used in a non-electric car driving at highway speeds. The design could also be adapted for use on watercraft or aircraft.

Claims

This document claims exclusive rights to the following:
1. A helical turbine blade used in parallel with fluid flow, such that it resembles a drill.
2. A "wind tunnel" used to capture and direct fluid flow along a blade as described in Claim 1.
3. An assembly of the parts described in Claims 1 and 2 designed to be embedded into the body of a vehicle to capture fluid flow as it passes along the outside of the vehicle body.
4. A turbine designed to be mobile such that it is affected by the flow of fluid as it moves.
5. A helical turbine blade that rotates around its shaft no less than one time divided by the number of blades and no more than one full rotation.
6. A "wind tunnel" housing designed to be modular so that multiple turbines can be attached in parallel to create a "turbine strip".
7. A helical turbine blade described in Claim 1 having an exterior angle between 45 and 60 degrees, inclusive.
8. An assembly of the parts described in Claims 1 and 2 having dimensions that scale to a tunnel diameter between 30 cm and 3 cm, inclusive.
9. A "wind tunnel" as described in Claim 2 whose inlet incorporates a nozzle to direct and accelerate fluid flow toward the outer edge of the helical blade described in

Claim 1.