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).
Comparison of the performance of six-blader and three-blader fans, detailing experimental limitations.
| Identifier | ExFiles\Box 75\3\ scan0148 | |
| Date | 20th November 1924 guessed | |
| -7- Contd. There is an impression that although the six-blader fan is better at low engine speeds, the three-blader fan is better at high engine speeds. Our experiments do not show any evidence of this. Even if the performance, irrespective of the power taken to drive and the speed at which the fan is driven, is under consideration, our experiments have shown that it is impossible, driving the fan in the way we do, to produce as big a thrust with the three-blader fan as with the six-blader fan. Whereas in our experiments the limit to which we could go on the six-blader fan was the available power from our motor, the limit on the three-blader fan was by no means this, but it was a fact that it was impossible to get it through the belt, running at the high speed necessary. Altogether, this fan problem is a little more complicated than appears at first sight, and has taken some thought to arrive at the results which we have already given. EFC. | ||