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Garth Magee
Founder
[email protected]
www.nullwinds.com
P.O. Box 475
Lawndale, CA 90260
310.675.4111
INNOVATIVE DRAG-REDUCTION METHOD AND APPARATUS FOR WHEELED VEHICLES
— PATENT PENDING —
Upper Wheel Fairings: First Tested on Road Bicycles
● Dramatically reduces effective vehicle drag induced by wheels
● Speed gains exceed 10 percent when facing only light headwinds
Designs Optimized for Drag-Sensitive Upper Wheel Surfaces
● Elevated Front Wings: Positioned directly ahead of upper wheel surfaces
● Elevated Trailer Skirts: Minimal surface area for reduced vehicle drag
● Aerodynamically-Optimized Spokes, Wheels and Tires
● Directed Exhaust: Deflects headwind from impinging on exposed upper wheels
Mechanically-Disadvantaged Lower Wheels Surfaces Remain Fully-Exposed to Headwind
Augmented Traction: By-Product of Reduced Upper Wheel Drag Minimizes Drag-Inducing Down Forces
“...It is my conclusion that when riding into a
headwind with the addition of the Null Winds
Technology Upper Wheel Fairings, any bicycle
will be noticeably faster at any speed!"
“The faired bike steered more true and felt more connected
to both the ground and the rider, while the stock bike felt
less stable and was more easily disturbed by the wind. The
faired bike was easier to pedal against the headwind, and
would be particularly beneficial on longer mostly flat rides."
— Jason Shutz, Cat-2 Time Trial Specialist
— Manuel Quiros, Veteran Velodrome Record-Holder
The Wind and Drag Profiles of the Wheel
Effective wind on Exposed Wheel moving against a Headwind (both with speed of V) = Up to 3V
Wheel = V
Velocity
V
2V
● Wind-Speeds Exceed Vehicle Speed
on Upper Wheel Surfaces
Headwind = V
Wind Speed on Wheel Surface
Reduction in Winds with Fairing
Null Headwinds
Headwinds = Vehicle Speed
Effective Drag Torque Resisting
Vehicle Propulsion
(for External Headwind = Vehicle Speed)
ω
Unfaired Wheel
Faired Wheel
When facing headwinds, shielding upper wheel surfaces saves energy since
power dissipated in drag is extremely sensitive to the impinging wind speed. (PDRAG α V 3)
NULLWINDS.COM
● Wind-Speeds Approach Null on Lower
Wheel Surfaces
● Wheel Drag Highly Concentrated on Upper
Wheel Surfaces
● Headwinds Exacerbate Drag on Upper
Wheel Surfaces
● Power Dissipation in Drag is Proportional
to Cube of Wind-Speed
● Faired Upper Wheels Substantially Reduce
Vehicle Drag
Ground-Level Wind = Null under null headwind conditions
= Headwind speed when headwinds are present
SMARTER CYCLING
WITH NULL WINDS TECHNOLOGY
Shielding Critical Upper Surfaces Reduces Vehicle Drag
● Faired Wheel Gains Rapidly Increase
in Stronger Headwinds
up to 20% faster
For more information email [email protected]
PPropulsion = DAverage
● Net Wheel Drag Force Incorrectly Centered
on Axle
● Net Wheel Drag Force Countervailed by Equal
Propulsive Counterforce Applied at Axle
PPropulsion
DAverage
● Drag Equation Treats All Wind-Exposed
Vehicle Surfaces Equally
● Drag Equation Employs Constant Average
Vehicle Drag Coefficient
● Not Accurate for Vehicles with Exposed
Upper Wheels
Drag Torques with Wheel Elevation
[Velocity = V]
No Fairing
Headwind = V
Upper Fairing
Headwind = V
Average Drag Moment
Over-Simplified (Airplane) Drag Force Mechanics
No Fairing
Headwind = V/2
Upper Fairing
Headwind = V/2
No Fairing
Headwind = Ø
Upper Fairing
Headwind = Ø
No Fairing
Tailwind = V/2
● No Explanation for Loss in Traction
PPropulsion = Applied Propulsive Counterforce
DAverage = Average Wheel Drag Force
0
5
10
15
20
25
30
Elevation above Ground [Diameter = 30]
Wheeled-Vehicle System Drag Force Mechanics
Drag Moments with Wheel Elevation
PPropulsion = DSpoke + DRim + GGround_Reaction
[Velocity = V]
GGround_Reaction x RWheel_Radius = DSpoke x [ESpoke_Drag_Elevation — RWheel_Radius]
DSpoke
PPropulsion
DRim
GGround_Reaction
PPropulsion = Applied Propulsive Counterforce
DSpoke = Net Spoke and Wheel Surface Friction Drag Force
DRim = Net Wheel Rim Form Drag Force
GGround_Reaction = Ground Reaction Slip Force (DSpoke Counterforce)
ESpoke_Drag_Elevation = Elevation of Net Friction Drag: DSpoke
RWheel_Radius = Wheel Radius
● Wheel Forces Levered About Stationary Point
of Ground Contact—Rather Than About the Axle
● Net Wheel Drag Force Countervailed by
Magnified (by Leveraging) Propulsive
Counterforce Applied at Axle
● Drag-Reaction Slip Force Opposed by Upper
Wheel Drag Torque Generated at Ground
Contact Point, Reducing Available Traction
● Drag Torques Increase Rapidly
with Stronger Ground
Headwinds
● Drag Torques Reduced
Dramatically by Shielding
Upper Wheel Surfaces
Upper Fairing
Headwind = V
No Fairing
Headwind = V/2
Upper Fairing
Headwind = V/2
No Fairing
Headwind = Ø
Upper Fairing
Headwind = Ø
● Drag Equation Treats Wheel Surfaces
Independent of Frame Surfaces; Impinging
Wind Speeds vary with Wheel Elevation
● Drag Coefficient is a Non-Constant Variable,
Non-Linearly Dependent on Both Headwind
and Vehicle Speed
● Drag Torques Increase Rapidly
with Rising Wheel Elevation
No Fairing
Headwind = V
● Net Wheel Drag Force Centered Near Top
of Wheel
Total Drag Torque
where:
Upper Fairing
Tailwind = V/2
● Drag Forces X Moment Arms
(About Ground Contact Point)
Cause Resistive Torques on
Various Wheel Surfaces
No Fairing
Tailwind = V/2
0
5
10
15
20
25
30
Elevation above Ground [Diameter = 30]
Upper Fairing
Tailwind = V/2
● Wheel Drag becomes Increasingly Larger
Component of Total Vehicle Drag in Stronger
Ground Headwinds
● Total Drag Torque
a Function of Exposed
Wheel Surface Area
at any Elevation
● Net Drag Torque
Centered High on Wheel
● Shielding becomes
Increasingly Effective
With Stronger Headwinds
● Vehicle Drag Reduced
Dramatically by Shielding
Upper Wheel Surfaces
Wheeled Vehicle System Drag Force Mechanics: Reduced Propulsive Counter-Force Countervails the Combined Wheel and Fairing Drag Forces
● Wheel Wind-Profile Diagram: Extreme Upper Wheel Wind Speeds Exacerbate Frictional Drag Forces
● Upper Wheel Drag Forces: Magnified by Leveraging Against the Propulsive Counter-Force Directed at the Axle
● Lower Wheel Drag Forces: Diminished by Leveraging for Reduced Effect on Overall Vehicle Drag
● Reduced Ground-Reaction Slip Force from Diminished Upper Wheel Drag Force Augments Effective Traction
● Vehicle Speed Gains Rapidly Increase with Either Rising Vehicle or External Headwind Speeds
● Suggests New Method for more Accurate Measurement of Vehicle-Drag in Wind Tunnels
Applications: Vehicles with Wheels Exposed to Headwinds
● Open-Wheel Racecars (rules permitting)
● Semi-Truck Trailers and similar
● Jeeps and similar Off-Road Vehicles
● Cycles: Bicycles and Motorcycles
Design Criteria: Reduce Drag on Critical Upper Wheel Surfaces
● Fairing Centered to Shield Most Critical Upper Surfaces
● Fairing Surface Area Restricted to Minimize Frame Drag
● Wheel Surfaces Drag-Optimized for Uppermost Location
Drag forces centered near top of wheel have a mechanical
advantage over propulsive counter-forces directed at the axle.
NULLWINDS.COM
● Slower-Moving Lower Wheel Surfaces Always Exposed
Surprisingly simple. Surprisingly effective.