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).
Letter discussing a report on wind tunnel tests for E.R. Hall's car, comparing aerodynamic K factors.
| Identifier | ExFiles\Box 90a\3\ Scan029 | |
| Date | 28th January 1935 | |
| K962 Exptl. Dept. HS{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}7/KW. 28th January, 1935. Reid A.{Mr Adams} Railton Esq., Messrs. Thomson & Taylor Ltd., Brooklands Track, Byfleet, Surrey. Dear Railton, Here is a copy of our report on wind tunnel tests done on E.R. Hall's car. None of the results obtained by these tests was incorporated on the car which ran in the Ulster Race. It will therefore be observed that the model which Hall is handing to you has a K.{Mr Kilner} of .00278, which compares most unfavourably with the K.{Mr Kilner} for our streamlined car of .00184. After we have done the obvious things such as putting fairings behind the front wings, putting the spare wheel in the tail etc. the K.{Mr Kilner} was reduced to .00238, which is still undesirably high. You will observe from the photographs that we did put the cowl on the front of the radiator without much success, but in this particular model we did not bring the cowl down to the floor as we have done on some of our previous wind tunnel tests. The road wheel horse power quoted is the clutch horse power less a certain percentage which we find is absorbed by the tyres and transmission. If there is anything you do not understand you will possibly be able to discuss it with me when you come up to Derby. Yours sincerely, | ||