Am 24.08.2020 um 06:23 schrieb William Claybaugh:
Most years there’s a race in France where the winner has to cover the
most miles in 24 hours....
I think it is the case that battery / IC engine hybrids have won that
race for about a decade now. They are easily and observably more
efficient than IC engines alone. But there was for a while an IC /
flywheel vehicle in that race that did not win...just sayin’.
But then we might also observe that a modern
F1 powerplant is past 50% thermal efficiency...you sure?
with a plus 100 hour lifetime.
All of which is intended to suggest that the present might be more
efficient than are our assumptions about the future.
Bill
On Sun, Aug 23, 2020 at 10:01 PM Henry Spencer <hspencer@xxxxxxxxxxxxx
<mailto:hspencer@xxxxxxxxxxxxx>> wrote:
On Sun, 23 Aug 2020, Rand Simberg wrote:
>> ...Back in the early 80s, SSI figured 600t of high-tech rotating
>> machinery as an energy buffer for a lunar catapult system;
Jordin found
>> that 40t of off-the-shelf truck batteries would meet the same spec.
>
> Yes, except the flywheels worked a lot better if you wanted to run a
> railgun. :-)
That was the theory :-). If I'm correctly remembering what Jordin
said,
after a lot of exasperating tinkering with fancy rotating machinery,
the
Eglin AFB experimental railgun switched to a hangar full of Sears
Diehards, which cost a lot less *and worked a lot better*. Turns
out you
can get 2000 amps out of one briefly...
Henry
