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).
The wind tunnel tests conducted on a Vanvooren Bentley scale model.
| Identifier | ExFiles\Box 161\1\ scan0049 | |
| Date | 10th November 1937 | |
| To Rm.{William Robotham - Chief Engineer} from Ev.{Ivan Evernden - coachwork} c. to Sg.{Arthur F. Sidgreaves - MD} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Sr. Da.{Bernard Day - Chassis Design} 1380 Wind Tunnel Tests on Vanvooren Bentley. --------------------------------- We tested the scale model of the Vanvooren streamline Bentley in Vickers Wind Tunnel, and have based its performance on the known performance of our late streamline Bentley B.23.AE. a model of which was also blown. The behaviour of the model in the airstream indicated a very smooth airflow over the body. The Flat Plate Method was used as we had no duplicate models for the Reflex Method, but the testing error was eliminated by basing the results on a comparison with the model of a known car, B.23.AE. which was tested in a similar manner. The tests lead us to the following predicted figures for 97.1 h.p. at the road wheels. Lap Speed 117 M.P.H. or 187 K.P.H. Flying Half Mile. 123 M.P.H. or 197 K.P.H. The corresponding figures for B.23.AE. with 92.5 H.P. at the road wheels were: Lap Speed 95 M.P.H. Flying Half Mile. 100 M.P.H. If a standard rear axle is fitted with the over-drive gearbox, a maximum speed of 120 M.P.H. is permitted. The most remarkable feature of this Vanvooren Bentley is that its windage drag is almost half that of B.23.AE. yet it is only very slightly less restricted in seat room than the standard Bentley. The front seat width at the elbows appears to equal the standard body, and although the seat is lowered, the headroom of the cushion is approximately our normal. Cont'd.{John DeLooze - Company Secretary} | ||