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 document on the efficiency and performance of different cooling fans, including standard and staggered bladed types.
| Identifier | ExFiles\Box 14\7\ Scan068 | |
| Date | 13th September 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/Std.6/KW.13.9.34. (3) From the attached curves it is seen that the standard fan is slightly more efficient than either of the other fans from a cooling standpoint, the two LeC. fans being approximately the same in this respect. Note: The cooling comparisons were done with an R.R. tube radiator. A similar temperature rise curve taken with the Harrison matrix radiator indicated that it is not feasible to reduce the fan size with this radiator. Summary. The better of these two fans (LeC.3747 and LeC.3748) is the staggered bladed one, and the only advantage (improved silence at the expense of approximately 1 B.H.P. increased power loss at top speeds) is due to its staggered blade construction and not to its altered blade shape. In view of this there seems to be no gain by using this type of blade but the present standard type fan should be tried with its blades staggered instead of symmetrically placed. We are at present experimenting with staggered fans on the 20/25 engine and shall endeavour to apply results to 40/50 fan. Hs{Lord Ernest Hives - Chair}/C.S.Steadman. | ||