MOI of a disc rotating about its centre point = 1/2 x Mr^2
MOI of a bar rotating about one end = 1/3 Ml^2
where
M = Total Mass
r = radius
l = length

If the mass is not rotating about its centre of gravity then you have to use the parallel axis theorem to calculate the additional MOI. This is
(Total MOI) = (MOI about centre of gravity) + (Area of object) x (distance of axle from centre of gravity).

so for vortexs disc if modeled as a large disc (200mm) with a smaller disc cut out of the middle (140mm?) and a bar put across (width 30mm) then total x-sectional area = 0.068 m^2
mass per unit area = 43.9 kg/m^2

Total MOI = 0.03 kgm^2

Total KE = 3.3 KJ

Similarly for strip:

MOI = 0.095 (seems a bit large)

KE = 6.4 KJ

Ive just done these in a rush and am pretty sure one of them is wrong .If Anyone wants me to explain my methods or any thing then just post your e-mail or e-mail me and i will send you the full calculations

Joe Townsend