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).
Page discussing engine fan design variations, including a performance comparison graph between two fan types.
| Identifier | ExFiles\Box 178\1\ img036 | |
| Date | 15th February 1926 guessed | |
| - 20 - cars to drive the fan through a small friction drive directly off the front end of the camshaft. The friction drive is evidently supplied to prevent the fan absorbing an unnecessary amount of power at high speeds as well as to cushion the inertia loads. If this is the case, heat dissipation from such a drive would still appear to be a considerable problem. GRAPH VIII Y-Axis: ENGINE POWER TO DRIVE FAN X-Axis: AIR THRUST OF FAN LBS WT Graph Data: - Dashed Line: STANDARD SILVER GHOST 6 BLADED FAN (IN-EFFICIENT) - Solid Line: 4 BLADED E.A.C. FAN (EFFICIENT) - Legend: IMPORTANCE OF FAN DESIGN (b) Variation in fan design. A badly designed fan will absorb a large amount of power and yet draw only a small quantity of air through the radiator. The two fans whose performance is depicted in Graph VIII illustrate the improvement which can be brought about by careful design, the power for a given thrust being reduced over 50% by using the EAC. type fan in preference to that of the Silver Ghost. contd. | ||