🚀 go-pugleaf

>In article <72306@cup.portal.com>, Ted_Eugene_Viens@cup.portal.com writes:
>> Jim many people have brought this up with fantasies of cars failing to bank
>> on corners and rolling wildly on hilly roads.  This rest on the ignored
>> assumption that the housing is rigidly mounted on the car frame.  If the
>> housing is mounted on flexible elastic mounts, the gyroscopic effects on
>> the car could be brought lower than the effects of a heavy set friend
>> bopping to heavy metal in the back seat.
>
>Ok, let's just check that.  Angular momentum (L) of the rotor is the energy
>stored divided by the angular velocity.  The energy stored is about 92000 kCal
.
>The angular velocity is anywhere from 2775 radians/s to 40,000, given the
>various designs posted.  At 2775, this gives about 140,000 J-s.
>Now, let's say you take 5 seconds to make a 90 degree turn.  Torque is
>the change in angular momentum over time.  The vector direction of the
>change in torque is tangential to the curve, and the torque is 1.414*L/5
>or about 40,000 N-m.  How about the bopper?  Let's say he's 200 kg (big),
>and is able to swing his body back and forth (180 degree) once a second
>and is 2 meters tall (we'll assume he's standing, and all his weight is in his
>head).  That's a heck of a bopper.  Ok, L=200*2*2*pi = 2500 J-s, and torque
>would be 5000 N-m, 1/8th of the slow-rotating big flywheel in a turn
>(the flywheel was 100 kg and 1 meter radius).  A smaller flywheel would
>exert less torque due to its higher velocity (this seems counter-intuitive,
>but it is true since energy is constant and energy goes as v^2, while
>momentum goes as v).  Of course, no one can bop like the bopper I proposed,
>and most turns succeed in much less than 5 seconds, so it would be a very
>small flywheel that would actually store the 92000 kCal and still exert
>less torque than your bopping buddy.  However, such flywheels are beyond the
>strength limits of any material, so they are figments of the imagination.
>
>
>--
>Richard Stead
>Center for Seismic Studies
>Arlington, VA
>stead@seismo.css.gov
>
Thanks Richard, for the informative and civil response.  Again, I have been
too lazy this weekend to run down to the library to obtain my own copies of
the physics equations, but my foggy memory of physics seems to follow your
math.  I did not notice in your response any reference to a flexible mount
for the FB.  I have seen 400 pound men oscillating on dance floors at more
than 1 Hz, and if the precessional torgue was reduced by a factor of eight
by a combination of flexible mounting and reduced rotor diameter, your treat-
ment of this issue appears to support my original position.  Thanks for your
support...  Bye...  Ted..