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).
Performance comparison between a standard fan shape and an improved shape, including calculations and notes on further testing.
| Identifier | ExFiles\Box 135\1\ scan0020 | |
| Date | 16th March 1932 guessed | |
| -2- Fan diameter 1' 10" Fan blades area 1250 sq. cms. Maximum revolutions attained 864. In standard shape: Consumption 310 Watts 100 metres air in 14 seconds = 7 metres per second 7/second = 420 metres per minute 420 metres per minute = 42,000 cm x 1250 sq.cm. = 52,500,000 ccm = 52.5 cbm. In improved shape. Consumption 265 Watts 100 metres air in 11 seconds - 9 metres per second 9 metres per second = 540 metres per min. 540 metres = 54,000 cm x 1250 sq.cm. = 67,500,000 ccm = 67.5 cbm. Maximum yield by improved form = approximately 28% Saving in consumption approximately 14% Further tests at your end will no doubt reveal what modification will become necessary to suit your conditions and we hope that practice will establish the fan's merits in its altered form. If our presence during or after tests be desired we are gladly at your disposal. Inasmuch as our own tests were conducted on the bench only, you will understand that we will appreciate the opportunity of seeing the fan working in the actual engine. We have retained the smaller fan and await your instructions in due course whether to convert it or not. We have made and kept jigs for the larger fans conversion which are of course at your disposal. The material used for the blade envelopes is duralumin. Any information as to best materials, gauge and tensile strength are gladly at your disposal. | ||