Re-inventing the Wheel?

Yes! Aerial Wheel!!!!

We are stuck with 14th-century screw propeller (Aerial Screw) technology for a very long time, trying hard to screw far ward without screaming. Replacing ICE engines with electric motors is not innovation! We have ignored birds and fish (billions of years of evolution) which push the fluid more efficiently and quietly. It's time to invent the Aerial Wheel!!!! Below are the 4 bullets which are going to revolutionize the UAM industry.
Air-Screw.jpg

1) Affordable, Reliable, Efficient & Low Noise VTOL:

  • SunPlower Propeller is low RPM (5-10x slower than screw propeller) - Low Noise!

  • Slow propellers are efficient (Power is square of the velocity) – Longer Range!
  • Simple 360⁰ Thrust Vectoring (No hinges/ swash plates/ linkages) – Reliable!
  • Low development and certification costs & faster time to market – Affordable.
More info at www.sunplower.de/technology

2) Faster & Efficient in thin Air:

Elon Musk is right: Electric planes become more efficient as we go higher in altitude (no need for oxygen for the electric engines) which allows more economical and faster flights.

Based on our recent measurements and in-depth analysis of propulsion on Mars conditions (just 1% atmosphere), it's evident that SunPlower Propeller is also optimal and superior for thin air environments.
 
In order to operate both on ground level for eVTOL (low RPM, High torque) and also at high cursing altitudes (high RPM, low torque), there is a need for a large operating range engine without a gearbox or multiple motors. This multiple orders of magnitude range of RPM is possible with a very simple trick. Variable Field Magnetic Motors (Increase motor Kv simply by offsetting the stator) allows higher RPM’s required for higher altitudes with less torque (sufficient in thin air). This not only increases the speed of the motor but also improves the efficiency of the motor by reducing the losses.
variable field permanent magnet motor-SM

There is also another simple method to increase the Kv rating dynamically (increase RPM) of the electric motor by simply switching motor configuration from Y to ∆ for even higher RPM at higher altitudes (Y configuration is optimal for re-gen during descend). This technology of switching in between Y-∆ configuration is proven & widely used in induction motor starters.

Climbing altitudes is power demanding and if this potential energy is wasted, then it’s not economical at all  (reason why the aviation industry is making losses). Next is the solution to this problem.

3) Re-Gen during Descend:

Regenerative braking allows the range of the EV (on the road) to be extended; the efficiency of capturing this energy is reported up to 70%. Regeneration on the ground for EV’s makes sense as the wheel rotates directly proportional to the vehicle's speed for both acceleration (discharge) and deceleration (charge). However, for air vehicles, this does not result in the regeneration of any useful power (proven already) using screw propellers.
 
Based on our analysis it’s possible to re-generate 15% to 45% of energy with SunPlower Propeller technology during descend. SPP acts as an Air Wheel (actually Air Cone) in the air which can rotate easily during descend at higher RPM – significantly more efficient than screw propellers (high Kv motors used for screw propellers are use-less generators). As SPP needs very low RPM high torque motors (very low Kv); which act naturally like an efficient generator as well when reversed. This enables efficient re-gen with very low configuration change (Y configuration is optimal for re-gen during descend, which generates higher voltages) and also eliminates the need for a separate generator/gearbox.
 
We are also exploring possibilities of using Jet streams at higher altitudes for re-charging the batteries in the air. This is only made possible with SPP. The secret lies in eagles flying at high altitudes without flapping wings.
 
4) Brake in the Air:
Today only a few high-end combat military air vehicles have fast decelerating braking capability in the air. As of today UAM vehicles cannot and don’t need this safety feature as there is not much traffic in the air. After a few years’ air traffic is going to increase significantly, imagine driving a car without brakes in busy traffic! Safety is first priority!
 
SunPlower Propeller allows fast decelerating braking capability in the air. This is not an extra feature that needs to be added – this comes for free from the architecture of the SunPlower Propeller’s 360⁰ directional thrust vectoring capabilities. SPP can also thrust backward at full speed!.