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).
Report comparing the performance, cooling effect, and power consumption of a standard versus an experimental 20 HP fan.
| Identifier | ExFiles\Box 75\3\ scan0056 | |
| Date | 19th February 1925 | |
| -3- Contd. Please refer to our "Further Note" on p.3. of EFCL/T19.2.25 - a report with reference to 20 HP. fans. From the results of driving two fans (a) At what we call corresponding speeds (i.e. speeds producing the same bench observed thrusts for given chassis speeds). (b) With the same engine fan speed ratio, it was pointed out that in the case of a higher efficiency fan which also has a lower speed-thrust curve, some speed of driving the fan lying between the above two limits should be selected; at the (a) limit one would get the same cooling effect at moderate speeds, improved cooling effect at high speeds and considerably less power and wear of belt at all speeds, and at the (b) limit would would get (using the improved fans we recommend) more cooling effect [handwritten]than in(a)[/handwritten] [handwritten in margin]at all speeds[/handwritten] still with less, though hot so much less, power required to drive and wear of belt. In a case, however, such as the present where the speed thrust curve of the experimental fan actually lies above that of the standard, it is clear that one [strikethrough]drixvexkxexpexxt[/strikethrough] is not even starting fair between the two fans until one drives the experimental fan at the corresponding speed, i.e. faster than the standard. Then the cooling effect might, as above, by hoped to be the same at moderate speeds, better at high speeds, and the power to drive and wear of belt less at all speeds. One could go further than this and drive the experimental fan at a higher speed than the corresponding speed, to correspond | ||