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).
Appendix from wind tunnel tests comparing performance calculations for a standard and a streamlined saloon.
| Identifier | ExFiles\Box 160\2\ scan0164 | |
| Date | 4th December 1933 guessed | |
| (1) WIND TUNNEL TESTS - APPENDIX. STANDARD SALOON. Road wheel H.P. = 92.5 at 4150 R.P.M. & 86 M.P.H. Axle ratio 4.1 to 1 Projected area 23.4 sq.ft. Constant T.R. at 30 lbs/ton = 51 lbs (Weight 1.7 tons two up). H.P. due to Constant T.R. at 86 M.P.H. = (51 X 86) / 375 = 11.6 H.P. Tractive Resistance due to Windage = (80.9 x 375) / 86 = 353 lbs. A = Projected area in sq.ft. K = co-eff. of air resistance in lbs/sq.ft. projected area per (M.P.H.)² R = Total air resistance in lbs. V = Speed in still air in M.P.H. R = KAV² K = 353 / (23.4 x 86²) = .00204 STREAMLINED SALOON CHASSIS H.23.AE. Road wheel H.P. = 92.5 at 4150 R.P.M. & 94.5 M.P.H. Axle Ratio 3.73 to 1. Projected area = 19.025 sq.ft. Constant T.R. at 30 lbs/ton (weight = 1.55 tons two up) = 46.5 lbs. H.P. due to Constant T.R. at 94.5 M.P.H. = (46.5 x 94.5) / 375 = 11.7 H.P. Tractive Resistance due to Windage = (80.8 x 375) / 94.5 = 321 lbs. | ||