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 two modified Phantom fans against a standard fan for power loss, noise, and cooling efficiency.
| Identifier | ExFiles\Box 14\7\ Scan067 | |
| Date | 13th September 1934 | |
| To E.{Mr Elliott - Chief Engineer} X7220 Hs{Lord Ernest Hives - Chair}/Std.6/KW.13.9.34. Report on Phantom Fans to LeC.3747 & LeC.3748. These two fans have a modified blade shape and construction - one has four symmetrically placed blades, the other has four similar blades but these are staggered; i.e., the angle between each pair is less than 90°. These fans were compared with a standard fan in the following manner :- (1) The power lost in driving each fan was measured (at top speeds) on the test bed (a Harrison matrix radiator being correctly positioned in front of fan). Curves attached. (2) The fans were compared with each other on a car from the standpoint of silence (a Harrison type matrix radiator being used). (3) The cooling efficiencies of the fans were compared on a car by allowing the engine to idle, full retarded ignition, the shutters being open and comparing the temperature rises in a given time in each case. Results. (1) From the attached curves it is seen that both these fans (LeC.3747 & LeC.3748) use slightly more than 1 B.H.P. to drive them than the standard fan does, the staggered bladed fan (LeC.3748) being slightly better than the symmetrical one. (2) The standard fan and the symmetrical fan LeC.3747 were approximately equal as regards noise, but the staggered bladed fan LeC.3748 was definitely quieter than either, there being less whine with this fan, the resulting note being a lower one. | ||