Ok, so the problem with some of the electric cars is that there isn’t a great way to keep them charged other than plugging them in to an outlet.
- There are solar cells, but they don’t generate enough energy quickly enough.
- Most electric cars have regenerative braking, but that doesn’t return a lot of power.
- I’m sure there is some energy returned when the car is coasting or rolling downhill, but again you had to use more energy to get up the hill or up to speed.
Well, here is my idea. It stemmed from the thought that electric cars are too quite. Why not have a pipe that runs under the car where the old exhaust ran and have it intake air on the front and then make a sound out of the back or sides like a trumpet or other horned instrument. The faster you go the louder and more noise it makes. I wasn’t thinking Harley type loud, but just enough to where you could here the car coming and give it an old time low motor-ish rumble.
But wait there’s more. Why just have the tube produce a sound? It seems that it should be possible to place turbines inside the tube or tubes that could use the wind force to spin and create electricity. I at first thought that you would have a small opening on the front that channels the air flow into chambers for maximum pressure at lower speeds (say 30MPH might be the optimum speed). Inside the chamber would be many little fans that catch the wind and spin, I envisioned the fans that run on computer CPU’s. Having a few tubes running under the car catching the directional airflow that is there anyway and spinning many little rotors would seem like it could make a lot of extra power. I guess you would have to account for the added weight of the tubes on the car, and the tubes may add to the drag, although the air does pass through the tube and is under the car catching air that was already broken by the front of the car. I liked the tube idea in that typical windmills try to catch air from many directions, with the car it can really only be going in one direction so the air is always coming from the front.
Then I got to thinking if an array of small fans was the right way to go, or if there would be more power generated by a turbine setup. Instead of 20 or more little fans in the tube, why not one turbine like in a jet that would be larger, yet spin faster with the available wind force. I had pictured like a tube from the front and a larger part in the tube sort of like the mufflers of today. Inside the muffler would be a turbine catching the forced directional air from the cars movement and creating power to return to the batteries.
So I did a little Google searching and did not find anything under “Tube Wind Turbine Generators”. I attribute this to the fact that it’s hard to force air down a tube. But in a car that is moving in a linear direction it isn’t. I did find some formulas on calculating the power you would get, but it’s based on Windmill type generators. It was interesting to read that a setup with the fan blades falls into the formulas given, and that a single fan would only be able to gather about 30-40% of the available force of the wind, which makes sense. So in the case of the array of fans it is possible to almost achieve near 100% efficiency as you would have a multitude of fans pulling the energy out of the force. Say if inside the tube you had 20 fans. The first fan takes 20% of the force and converts it to energy, then the next takes 20% of what is left and so on. In my theory, if you want to call it that, at 30 MPH all fans would be spinning, at 20 MPH maybe only the 1st 15 fans have enough force to spin and the last 5 don’t have enough wind to spin. Of note though at 40MPH there might not be as much gain as the fans would all be spinning and at some maximum revolutions and thus not generating any more energy than at a lower speed.
Then I think about something like a jet turbine that would spin faster.
Then I have the thought that current wind turbines are attached to a generator. The small fan idea works in that each small fan could have a small generator and have wires feed out of the tube. A jet turbine type fan would need to be attached to a generator too. And as I think about it the jet turbine would not use up as much air as the array of fans would, although you could put 2 or 3 turbines in the tube to gather the passing air.
That is it in a nut shell. It totally seems plausible to be able to have inlets on the front of an electric car that force air into a tube that later passes the air over either fan blades or though a jet turbine of sorts that would be able to generate electricity for the car while it was moving. The trick is how much energy could the tube create, how much weight does it add, how much drag does it create, and how do you keep the insides of the tube from gathering junk from the road?
