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).
Comparative test results of two engine fans, discussing differences in thrust and power consumption.
| Identifier | ExFiles\Box 75\3\ scan0054 | |
| Date | 24th February 1925 | |
| To Hs.{Lord Ernest Hives - Chair} from EFC. c/c Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} X.1017. FAN TESTS. With reference to your Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG18.2.25 and Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG18.2.25, we have made comparative tests of the two fans handed to us in condition as received. In the first place it should be pointed out (1) That the fan referred to as the Goshawk type of EAC. fan is not similar to the EAC. fan which we tested and which we had looked upon as being the (for the present) standard EAC. fan, in two respects :- (a) That the fan has been cut down from 23" dip dia. to 22". (b) That each of the four blades has been given a sharper angle by twisting. (2) That the fan referred to as the EFC. fan is not like the best EFC. fan so far tested in two respects, e.g., (a) It also has been cut down from 23" to 22" dia. (b) It has not the same amount of curvature on the blades as the best fan tested, in fact it is considerably flatter. The result of these differences is that, whereas, comparing our best experimental EFC. fan with the standard EAC, there was observed a considerably larger thrust for the same speed (not to mention also the smaller amount of power to drive), on comparing the two fans at present under consideration, the thrusts for a given speed are actually reversed and are thus consistent with the road test results, though the power required to drive at a given speed remains less as before for the experimental fan than for the modified standard. Contd. | ||