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).
Wind tunnel tests on a streamlined Bentley bonnet design to reduce turbulence.
| Identifier | ExFiles\Box 160\2\ scan0111 | |
| Date | 9th January 1938 | |
| x 458 To EV.{Ivan Evernden - coachwork} from E.{Mr Elliott - Chief Engineer} E.2/HP.8.6.33. 9 JAN 1938 c.c. Mr. Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} re Streamlined Bentley Bonnet. We send you herewith, as requested, a print of LeC.3525 showing the above, which you propose to incorporate in the 3rd wind tunnel model. In this design the object has been to fair the wings into the bonnet shape and so eliminate the chasms that at present exist between the wings and the bonnet. It has been found in thick wing monoplanes that much turbulence occurs at the junction of wings and body, and that considerable gain in speed has been achieved by fairing the two together. In LeC.3525 the front mudguards are treated as the thick wings. We believe the bonnet can be made a practical job as shown, and that engine accessibility will not be impaired if the bonnet is made a little wider than at present, as shown on plan. There is another point about these wind tunnel tests to which attention might be given and it concerns the underpart of the car. We should like to know how important this is relative to streamlining the nose and tail of the car, so that we could say whether it would be worth while to have a smooth underpan from front to rear on a car of the No.3. model type. A recent article in the S.A.E. Journal gives some data on experiments rather indicating the importance of this feature, and suggests that No.3. model might be tried with different contours underneath. Att: LeC.3525. E.{Mr Elliott - Chief Engineer} | ||