If you remember, that is the style of dyno used to test your car last November
at the Dyno Shop. I believe that one is rated at 1000 hp. I think that the
flywheel is not very large in diameter, but is long. This would keep the
stresses down and make it less likely to explode. An easy way to measure the
moment of inertia (polar, I think) is to apply a constant torque and measure
acceleration. Gravity can supply the torque by hanging a weight from a wire
wrapped around the flywheel. Keep the weight small and speeds low to reduce
aerodynamic effects and you should be able to get within 1%.
Bob Palmer wrote:
> Sounds like a simple, straightforward dyno system that should give at least
> very repeatable, if not accurate, results. The accuracy would depend
> primarily on knowing the exact moment of inertia of the flywheel, which you
> should be able to calculate to within a few percent. I guess they could use
> the electric motor to load the system and measure the electric power output
> that balances the engine's input, but that would involve more calibration
> factors. Should be pretty repeatable though. I'll bet the size and weight
> of flywheel needed to handle 1000 HP is pretty huge. Let's see now, if we
> make it out of boron fiber composite and use depleted uranium for the
> weight, we could reduce it's size and mass a lot. And I guess they will be
> needing a new use for depleted uranium, now that the military has decided
> that it and lead are an environmental hazard. Is there a category for
> inertial powered land speed record cars? I know they have one for battery
> powered cars. Maybe we could work on the fastest inertial powered Sunbeam.
> What would it take to break 200 mph?