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).
List describing various fan designs and modifications tested, with their corresponding diameters.
| Identifier | ExFiles\Box 75\3\ scan0061 | |
| Date | 19th March 1925 | |
| 19.3.25. NUMBER OF DESCRIPTION OF FANS TESTED. FAN TIP DIA. 10. Fan as originally made (23" dia.) (with small negative angle). 23" 11. Leading edge given slight positive angle. 23" 12. No.2 fan as originally made, i.e. test (10) repeated on a second fan. 23" 13. Curvatures of blades reduced (Blades almost flat). 23" 14. Slight positive angle as in (11) but with increased curvature of blade, i.e. with trailing edge bent round more. 23" 15. Fan made in the shop (22" dia.) but belt into the considered best shape in the lab. Angle about 28°. Curvature about 10. Performance good. Handed to D.O. 22" (16a. 16 as received.) 16. Same as No.15 but with wider blades. Small negative angle. 22" 17. Angle of attack increased. 22" 18. Blades cut away and angle of attack again increased. 22" EFC. | ||