From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Calculation of the radius of gyration (K²) for car model 11-G-111 (landaulet body) by swinging.
| Identifier | ExFiles\Box 107\4\ scan0088 | |
| Date | 16th January 1928 guessed | |
| X-4538 TO FIND K² FOR 11-G-111 BY SWINGING. X5830 (LANDAULET BODY, SPARE WHEEL AT REAR). Let K²_GT = K² of total car (including axles) about c.g. of total car. = T² pg / 4 π 2 - p² ft² Where p = distance of c.g. from point of support when swinging = 10.167' T = 3.9 secs. Ther K²_GT = 22.6 ft². Weight of total car = 4004 lbs. ∴ I_GT = 4004 X 22.6 = 90,500 lbs.ft². From this must be subtracted the axle inertias about the same point. Weights are ( Front 305 lbs. k² = 1² + 6.083² ( Rear 485 lbs. k² = 1² + 4.708² Inertia for two = 305 (1² + 6.083²) + 485 (1² + 4.708²) = 22,840 lbs.ft². ∴ I_G = Inertia of spring part about c.g. of spring + unsprung parts = 67,660 lbs.ft². Weight of sprung part = 3214 lbs. ∴ k²_G = 67,660 / 3214 = 21.06 ft². To find position of c.g. of sprung part. contd :- | ||