Alright tech. heads...gyro powered cars!

[MAKG]

You're overestimating it, but your point is well taken.

1 HP is 750 W, so 50 HP = 38 kW. So it's 3 shells instead of 7. Still not much fun to contemplate.

 

[Wicked_Sludge]

the gyro buses used a 3300lb flywheel spinning 3,000RPM. granted a bus has a lot more mass and load carrying capabilities (for sheilding the gyro) than a car...and whos to say how safe the buses actually were...this was the 50's after all.

i think you guys are a little on the high end for my original 12kwh estimate. 12kwh = 16.08 hp/hours, right? 50 hp/hours would be good for about 176 miles. its still a lot of energy, no doubt...but no more than a tank of gasoline....its just harder to contain kinetic energy than it is potential energy.

would a single, virtical axis gyro effect steering? or only pitch movement?

 

[Will]

It seems worth building a functional model. I don't know what happens with the gyro when you upset it. I was sort of afraid the car would suffer a fender bender and suddenly leap up and go flipping off down the street like Taz.

 

[MAKG]

would a single, virtical axis gyro effect steering? or only pitch movement?

Turning the car on a stationary rotational platform would not be a problem.

The centrifugal force due to a real (moving) turn would be a LARGE problem. Precession and all that.

 

[arkantor]

i still think if a bus carrying 60 passengers could travel 4 miles on nothing but a giant flywheel with 50's technology...that you could make a 2,000lb (base weight before the flywheel) car go further. is it impractical? maybe. but americans drive many an impractical vehicle. H2 anyone?

but if my math is correct on my first post...the flywheel need only weight 400lbs. thats about the weight of the motor and transmission you will be removing. granted it will be slightly heavier after adding a few hundred pounds of electric motors/ wiring/ scatter sheild, ect. but that doesnt seem all that far fetched to me. the biggest problem i see so far is countering the gyroscopic forces. i think mounting the device on a gimble could work, but then you need a 5ft dia. area for the thing to turn in, plus space for a scatter sheild.

I do not want to be anywhere near something weighing 400 miles spinning at a reasonable speed.

You also say you can not charge a battery fast enough. "it took a maximum of 3 minutes charge time to travel almost 4 miles at almost 40 miles an hour." I am on a hybrid vehicle team, (click the link below). We do not connect our battery to any outside power source. The battery charges enough from stopping to hold enough power for acceleration. Our school is in a valley and we drive the thing all over the place (2000 miles around Lake Michigan, up and down mountains) and there has always been enough energy stored in the battery. It goes from 60% to 90% State of Charge(You have to keep the state of charge between these two points or you will fry the battery) in one 30mph-0 stop no problem. So I guess what I am saying is that a battery can easily do what you are saying in a safer manner.

I would not want to drive anywhere near something weighing 3300 lbs spinning at 3000 rpms. Imagine if the flywheel cracked? There would be pieces flying everywhere, I don't know if a splatter shirld could hold that. There is a lot of stored energy there.

 

[Wicked_Sludge]

It goes from 60% to 90% State of Charge(You have to keep the state of charge between these two points or you will fry the battery) in one 30mph-0 stop no problem.

you are also charging a MUCH smaller battery than what would be required to drive a vehicle 50+ miles on battery alone. ever seen the size of the battery packs carried by electric plug-in vehicles? even production vehicles using regenerative breaking (like the electric ranger) needed 1100lbs+ worth of batteries to travel 60 miles. these take all night to charge, even using a 220-volt source.

 

[krugford]

you are also charging a MUCH smaller battery than what would be required to drive a vehicle 50+ miles on battery alone. ever seen the size of the battery packs carried by electric plug-in vehicles? even production vehicles using regenerative breaking (like the electric ranger) needed 1100lbs+ worth of batteries to travel 60 miles. these take all night to charge, even using a 220-volt source.

Didn't the electric ranger use NiMH? I bet you could cut that pack down to 300-400lbs and increase the range with Li-poly depending on the cells used. The price of Li-ion and Li-poly cells are coming down and they are becoming more durable and more well known. Just don't catch them on fire or the DOT is gonna have a hole to fill where your car was...

 

[Wicked_Sludge]

only some of the ranger EV's got nihm batteries...those were the 1100lb packs i was referring to. the lead acid packs were about double that. the nihm packs took 6-8 hours to fully charge.

found a few interesting sites on gyro energy storage:

http://www.damninteresting.com/?p=909
http://www.answers.com/topic/flywheel-energy-storage?cat=technology

both suggest that 2 counter rotating flywheels would have a total angular momentum of zero. also, it seems that flywheels have much higher efficiency than most other methods of energy storage. energy density is upward of 130Wh/kg, vs 30Wh/kg for lead acid. energy efficiency is also up to 90% in flywheels, versus 60-70% for lead acid (including charger inefficiencies).

 

[MAKG]

The TOTAL angular momentum is zero, but the angular momentum of each individually is not. They will not turn the vehicle. But they WILL require quite a lot of weight in the frames and other supporting structures (e.g., bearings) to keep from breaking. Each will precess and nutate individually given outside forces. Since no frame is truly rigid, some angular momentum will "leak" when external forces (like centrifugal force in a turn) acts upon the vehicle.

And it doesn't even come close to addressing the safety issues.

 

[AllanD]

Turning the car on a stationary rotational platform would not be a problem.

The centrifugal force due to a real (moving) turn would be a LARGE problem. Precession and all that.

What would be a problem is the precession that would result from a pitch change.

Starting up a grade or going from level ground into a downgrade would be worst, the precession would produce an almost irrestable yaw, but the likely overcorrection from the driver would be worse and the bus would wind up on it's side.

Yes, even with two counter rotating gyros any force acting
on the gyros at right angle to it's rotating axis would produce unpleasant results.

Is anyone gettign a picture of just how compact an energy source liquid fuels really are?

AD

 

[triumphrider-1]

UPS was looking at using flywheels on their delivery trucks to help with acceleration (they figures they could save X% by running this along with their desiels. One of my schools professors was working with them on the calulations and tests, I'll see of I can find the article our paper wrote up on it.

Ok, here is a link to the article:
http://kettering.edu/visitors/storydetail.jsp?storynum=514

 

[Wicked_Sludge]

that system ups is testing is called a hydraulic accumulator...using hydraulic parts to store energy in tanks of compressed gas. also a neat idea.

i saw a blurb the other day while looking for info on gryo powered vehicles where some company in texas had created a gasoline/gyro hybrid of sorts. a small car engine was used to keep the gyro spun up to speed, while the gyro and traction motors actually propelled the bus. it was said to have a 35% improvement in fuel economy over a standard bus with little or no loss in performance.

so it seems the best way to prevent precession from effecting the vehicles handling would be to mount the entire enclosure (flywheel and some sort of uber bulletproof enclosure) on a gimbal. that is unless the vehicle just way out weights the gyro, then the gyro would have no choice but to do what it was told.

i think the safety issues could be overcome with a little ingenuity. perhaps a free hanging kevlar curtain (to stop bullet-like projectiles) backed by a concrete-filled steel ring (to stop large junks from taking off and rolling down the street). nothing will be absolute....this is why people die in car accidents now....and they will continue to do so in the future. how much kinetic energy is contained in a fully loaded semi driving along at 70MPH? apples to oranges you may say..but is it?

 

[krugford]

hmmm, I think the "heavy ass high speed flywheel" thing still scares me a little, but then again, I'm perfectly willing to drive down the road with a lithium-ion pack at my feet, so to each his own.

I believe that any of the safety concerns could be taken care of in an efficient manner, it's just a matter of solving the problem and living with the risks.

AllanD is right. Right now we have a small fuel cell that contains a flammable (but not too flammable) fuel that is easily stored at room temperature as a liquid. It's stable, easy to transport, and poses very little risk in an accident. It also is pumped from the ground, refined, and put into your tank with a very high "well to pump" efficiency.