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 testing of a four-bladed fan, noting improved efficiency and noise levels, with plans for further modifications.
| Identifier | ExFiles\Box 75\3\ scan0026 | |
| Date | 17th December 1924 | |
| Contd. -3- EFC1/T17.12.24. have a four-bladed fan made with an EAC. hub, on which the blades were similarly shaped, but larger, up to the full dia. (23") of the ordinary EAC. fan. It was immediately found on running this fan that it gave a better efficiency than any of these previously tested. It made far less noise. The type of noise made (something between a swish and a hum) by the fan was suggestive of its performing upon the air in a more correct manner. The curves of this fan are labelled with the fig. 10. Our further programme consists in making progressive modifications to the blades of this fans with a view to still further improvement, though very little improvement is anticipated. At the same time a similar fan is being made up for trial on the chassis. It is also arranged that an experimental Goshawk fan be made with four blades, starting with the full possible fan dia. and with the blades very wide,- something like a Maltese Cross. Progressive alterations and cuttings down of these blades can then be made to find out what is really the best shape which can be produced from sheet material. Thus a further report, giving similar results with these modifications will follow in due course. EFC. | ||