A Promethean Thought Experiment


The Alstom made X40 electric passenger train has a power-to-weight ratio of 12 watt per kg (2.400 kW / 205 tons) and a maximum speed of 200 km/h (fig. 9, fig. 10).

Suppose one would flatten an X 40 electric passenger train into a disk of 205 tons with a diameter of 20 meters, fit it with in-wheel electric traction motors and put it on a pivot and a circular rail (fig. 1, fig. 2). Would the power-to-weight ratio of 12 watt per kg of X 40 train, which has a maximum speed of 200 km/h, be enough to give the disk a speed of 45 km/h (measured at the disk's edge) and rotating it 12 times per minute?

Would this be possible? Why would it not be possible? The disk has the same weight as the X40 electric train and is subject to rolling resistance, aerodynamic drag etc. just like the X40 train is. Therefore, the 12 watt per kg power-to-weight ratio should work for both.

Fig. 1 -A "Flattened" Electric Train Fig. 2 - Cross-section View "Flattened" Electric Train
Electric train turned into disk powered by in-wheel electric traction motors
Cross-section view electric train turned into disk powered by electric traction motors

Next, by fitting permanent magnets on the edge of the disk and by building an iron-less stator around the disk, the disk turns into a generator (fig. 3, fig. 4). Will a 12 watt per kg power-to-weight ratio (2.400 kW) still be enough to spin the disk at 12 rpm, giving it at a speed of ~ 45 km/h (measured at the disk's edge)?

If this is possible, it just generated excess energy! Please do not feel fooled and continue reading.

The details like the disk's diameter of 20 meters, the disk spinning at 12 rpm and the disk's speed of 45 km/h measured at its edge, are not random picks, but are data from a science paper on a wind turbine generator (fig. 7fig. 8). The generator's rotor has the same diameter, rpm and travels at the same speed as the disk.

This generator (rotor and stator) weighs 145 tons and can generate 10 MW (10.000 kW). The disk / rotor (fig. 1, fig. 2, (fig. 3 , fig. 4) weighs 205 tons and consumes 2.400 kW power. This means there is a net output 7.600 kW of excess energy.

The laws of thermodynamics rule out excess energy. So, where did all the power go? Surely, there is some mechanical loss created by the disk spinning around the pivot, but does that gobble up 7.600 kW?

Rolling resistance and aerodynamic drag are already covered by the power-to-weight ratio of 12 watt/kg (2.400 kW). Furthermore, full power (2.400 kW) is only needed to drive at its maximum speed of 200 km/h. The disk / rotor only needs to drive at 45 km/h in order to generate 10.000 kW.

Do forces like hysteresis or eddy currents create an "electromagnetic drag" that takes 7.600 kW of power to overcome? That is enough power to run another three X40 electric trains! Each X40 electric train weighs 205 tons! The margins look large enough to suggest up to 7.600 kW of excess energy is plausible.

It is possible to increase these margins by remodeling the way the disk is powered (fig. 4, fig. 5). The wheels are made stationary and fitted in a circle, just like the wheel train in fig. 11. The electric motors are fitted with a pinion gear that drive an internal ring gear or pin gear (fig. 12 , fig. 13) fitted on top and close the edge of the disk. This saves quite some weight since electric motors and steel wheels are heavy.

What do you think? Did the thought experiment make the generation of excess energy plausible? If you want to share your views you can do so via email (feedback@prometheusturbine.info) or Twitter.

Thank you for your visit and time!

N.B. This a partial rewrite of the previous version.

Fig. 3 - Flattened Train Morphed Into Prometheus Generator Fig. 4 - Cross-section View Prometheus Generator
Flattened Electric Train Morphed Into Prometheus Generator
Cross-section view of Prometheus Generator

Fig. 5 - Prometheus Generator Powered Via Internal Ring Gear
Fig. 6 - Cross-section View Prometheus Generator Powered Via Internal Ring Gear
Prometheus Generator Powered Via A Ring Gear
Cross-section View Prometheus Generator Powered Via A Ring Gear

References

Fig. 7 - Cross-section View Wind Turbine Driving iPMG Fig. 8 - Comparing iPMG vs. Iron-cored PMG
Cross-section view of a horizontal axis 10 MW wind turbine
Specifications of a 10 MW ron-less Permanent magnet generator vs. the specifications of a iron-cored permanent magnet generator used in a horizontal axis wind turbine (HAWT)

Source paper: brage.bibsys.no

Fig. 9 - Alstom X40 Electric Passenger Train Fig. 10 - Alstom Specifications X40 Electric Passenger Train
Alstom made X40 electric train at Eskilstuna station
Source: X 40 electric train on Wikipedia
Specifications of a the X40 electric train made by Alstom
Source: X 40 electric train on Wikipedia

Fig. 11 - Wheel Train Car Turntable Under Construction
Wheel train car turntable under construction

Fig. 12 - Ring Gear And Pinion Gear Fig. 13 - Pin Gear Plus Electric Motor And Pinion Gear
Pinion gear and internal ring gear

Source: nbcgroup.co.uk
Pin gear and electric motor
Source: Unknown.