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).
Final investigations into the efficiency and shape of 20 HP fans, and a request for an EAC fan.
| Identifier | ExFiles\Box 75\3\ scan0037 | |
| Date | 4th February 1925 | |
| X1017 To RMC. from EFC. EFC2/T4.2.25. X.1017. RE FANS. We have now finally completed our investigations of 20 HP. fans and are satisfied that the last fan you made up for us to our requirements is quite as efficient as any we have tested, and representative of the best that can be done in this direction. This particular fan we are submitting to the D.O. so that they can take exact particulars of the shape. The previous one, which is nearly as good, we are handing to you and would like you to fit this to one of the current 20 HP. chassis. We shall also hand to you the other one when the D.O. have finished with it, to be fitted to another 20 HP. chassis. Further to this, we are again turning our attention to EAC. fans and shall hope that you will be able to let us have an EAC. fan, in the first instance with blades proportionally a little wider than this most approved 20 HP. fan, but otherwise similar in shape. It appears that there is just the right width of blade. We have proved that the very wide blades are not satisfactory and it is also evident that very narrow blades are not, therefore there must be the right width. EFC. | ||