The WindWheeler is a wind-powered vehicle. The WindWheeler is a road-legal recumbent with pedal assistance available in all wind directions. At headwinds, the pedal assistance will be electrical. At a crosswind, you get support from the wind up to a maximum of 25 km/h. The speed is limited to 25 km/hour by regenerative braking. In this way, you can drive safely with the WindWheeler on the road on windy days.
The WindWheeler uses a balancing wing as a sail. In this way, you need a smaller area for the same propulsion force. The balancing wing is self-regulating and adjusts automatically to the wind direction. You can adjust the setting of the wing sail using an App. The self-regulating wing sail makes driving the WindWheeler easy also for non-sailors. The WindWheeler is an e-bike with a max speed of 25 km/hr. At a strong breeze, both speed limiting and generating power by regenerative braking occurs.
To be road-legal using a recumbent with wind assistance means you have to meet several requirements concerning safety and comfort. Also, the recumbent should be practical in use and does not take too much storage space. These criteria have been taken into account in the design of the WindWheeler.
There is a working scale model on a scale of 1 to 7 with promising results. Currently a full-size prototype is under development. Curious?
You want to know more about the WindWheeler, or you have questions? Or you want to offer help? Please do not hesitate to contact me.
Driving on wind power is nothing new. In the Netherlands, Maurits van Nassau, later Prince of Orange, introduced the sand yacht in 1862, designed by inventor Simon Stevin. They drove with an unprecedentedly high average speed of 40 km/h for that time from Scheveningen to Petten.
A wing more effectively converts the airspeed into a force. Especially in the case of low vehicle friction, high speeds can be obtained. For example, the Greenbird. Since 2009, Richard Jenkins has set the world record for land sailing with this vehicle with a top speed of +/- 200 km/h (3 to 5 times the wind speed).
Figure 2. The Greenbird. Photo: Peter Lyons .
A wing converts the airspeed into a force perpendicular to the direction of the airflow. At an aircraft, the air flows opposite to the flying direction, resulting in a force vertically upwards. That is why one usually speaks of lift force.
For a vehicle with a vertical upright wing, the lift force is horizontally directed. The lift force can be divided into a forwarding force and a force in lateral direction (figure 4).
Figure 4. Balanced wing sail.
Wings usually consist of the main wing and a flap. The Angle of Attack and the flap deflection angle determine the generated lift force. Both angles are adjustable, meaning the lift force is adjustable between 0 and a maximum. Due to better efficiency, the maximum lift force of a wing sail is about twice a comparable traditional sail. The tail wing ensures the balanced wing sail always has an optimal Angle of Attack. The tail wing balances the torque caused by the main wing sail. The tail wing works the same way as the tail of an airplane. In Figure 4, the lift force generated by the wing causes a counterclockwise torque. At the same time, the tail wing generates clockwise torque. In case the wing sail is in balance, both generated torques counterbalance each other.
The airflow around the wing of an aircraft is completely determined by the speed of the aircraft. For traditional sailing ships, true wind mainly determines airflow. For fast sail crafts, like the Greenbird, the apparent wind angle and speed change according to the combined speed and direction of each the craft and the true wind. It’s called apparent wind. The apparent wind is the vector sum of the velocity of the headwind (which is the velocity a moving object would experience in still air) plus the velocity of the true. The apparent wind speed is usually higher than the actual wind speed unless the wind is coming from behind. A wind-powered vehicle is, therefore, partly self wind generating.
Figure 5 Animation wind-powered vehicle with speed limit.
On a wind-powered vehicle, we must therefore calculate with apparent wind. Apparent wind generates forwarding force and lateral force. The forwarding force determines the vehicle's speed. The lateral force can cause the vehicle to tip over. As shown in the animation in figure 5, increasing vehicle speed is rapidly increasing the lateral force, resulting eventually in tipping over. For the Greenbird, this was solved by building an extremely wide vehicle. However, this solves the tipping over but makes a road-legal vehicle impossible. For the WindWheeler, we limited the lateral force by maximizing the vehicle speed. Regenerative braking is forcing the speed limit and, the surplus of power is generating electricity.
WindWheeler equips a recumbent bike with wing(s). WindWheeler is a module that can be mounted on almost any (recumbent) bicycle replacing the rear wheel. The WindWheeler module increases the width of the recumbent bicycle gives it two rear wheels. In this way, the WindWheeler becomes very stable. At the same time, the WindWheeler equips the recumbent bike with a freely rotating wing sail with one or two wings that provides the propulsion on wind power. The balanced wing sail automatically adjusts itself to the correct apparent wind direction. The other parameters of the wing sail, such as the Agle of Attack and the flap deflection angle, can be set using the WindWheeler App. The WindWheeler module is equipped with a direct drive e-motor for pedal assistance at headwinds. The e-motor drive train is coupled to the rear wheels through a differential and ensures the desired speed up to a maximum of 25 km/h. In a strong breeze, the WindWheeler produces power by regenerative braking.
Designing the WindWheeler, the legal requirements of a pedelec have been taken into account. In addition to wind propulsion, the WindWheeler's main design requirements were safety, ease of operation, comfort, ease of use, and affordability.
With its width of 1.45 meters, the WindWheeler must officially drive on the roadway in built-up areas. In the countryside, the WindWheeler is allowed on the bicycle paths.
The height of the WindWheeler takes into account a headroom of 2.5 meters at bicycle tunnels and flyovers.
The balanced wing sail automatically adjusts to the wind direction and, the lift force is easily adjustable with an App (Android).
At headwinds, electrical pedal assistance is available.
A very stable four-wheeler can be created by combining the WindWheeler module and a tadpole recumbent trike (a recumbent with one rear wheel and two front wheels).
Lowering the wing is very easy. An upright WindWheeler with a lowered wing takes limited floor space.
See the specifications section for more features.
Safety has drawn much attention to designing the WindWheeler.
The wing sail position is behind the driver's seat. So the driver's view will not be limited.
The low center of gravity and the limited height of 2.5 meters provide a lot of stability.
The four-wheel version makes the WindWheeler even more stable due to its larger effective width.
The wing sail is self-adjustable therefore requires less or no attention of the driver.
• The speed of the WindWheeler is adjustable and maximized to 25 km/h.
The combination of features makes the chance of tipping over nil compared to a beach sailor/sailing bike. The balanced wing sail is less sensitive to sudden wind shifts and gusts. Through the speed limitation, the lateral force is limited.
|Max width||:1.45 meter|
|Max height||:2.5 meter|
|Height recumbent||:1.05 meter|
|Number of wheels||:3 or 4 (A four-wheel is more stable)|
|Length||:2.4 to 3.4 meter (depends on recumbent)|
|Weight||:+/-40-60 kg (depends on recumbent)|
|Rear wheel||:26 inch|
|Motor power||:250 Watt (maximized by motor controller)|
|Max speed||:25 km/hour (maximized by motor controller)|
|Battery capacity||:free choice|
|Ground space upright storage||:1.45 x1.3 meter|