Obtain a cheap plastic hand crank generator or several and play.
That will show you much of what you need to know.
If you turn the handle 1/8th turn (45 degrees) in 1/4 second then its
RPM is 60/time_to_turn x fraction of turn =
60s/0.25s x 1/8 turn ~~= 30 RPM.
In engineering 30 ~~~= 100 in many cases :-).
But if you want closer to 100 RPM then a 3 or 4 to 1 step up gear ratio will give around 100 RPM.
SO coupling the shaft to the alternator with a one way clutch and a say 4:1 speed up gearbox gives you about what you want. One stage of the epicyclic gearbox in many battery electric drills may be about right. These may have multiple stages to get higher ratios.
Just turning the chuck on a battery electric drill and measuring motor voltage produced may be worthwhile. Slightly tidier than this ideally.
A useful rule of thumb is Power is ~~~= RPM x kgm
Here RPM = 100 and torque = torque in / gear ratio = 1.12 Nm/4 = 0.28 Nm ~= 0.028 kg.m
So power = kg.m x RPM = 0.028 x 100 = 2.8 Watts.
This is produced only during 1/4 second of turning so energy
= power x time = 2.8W x 0.25s = 0.9 Watt seconds = 0.9 Joule.
A useful amount of energy.
My experiments with cheap plastic squeeze type hand alternators shows they make about 1 Watt with very enthusiastic cranking so the above calculation is "in the order of right".
Flywheel does not alter energy delivered but can modify user handle-feel and rate of delivery - eg if a flywheel is spun up by a 1 way clutch it may spin down over 1+ seconds and deliver energy at a less peaky rate.
Bonus: Obtaining energy from the opening or closing door is liable to be rather more productive if suitable to purpose. The door can eg have a spring closer and drive the alternator on one or both halves of open/close cycle. Energy taken from this source is liable to less noticed and easier to obtain in greater quantity.
Many ideas here
and here - each image links to a related page.
Cheap plastic hand crank alternator.
Mechanical efficiency is usually poor.
Note gear ratio is probably higher than apparent as another gear is probably not shown. ie their alternator spins MUCH faster than yours. The plastic Z-ish shaped piece in the flywheel acts as a one way clutch/pawl.
from here hand squeeze generator
You can buy these for far far too much $ on ebay OR pull apart old CD or DVD drives.
Stepper motors also may serve. Old large ones from 5.25" floppy drives (remember them :-) ) are usually better.