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).
Bench experiments on the power required to drive a 40/50 radiator fan with six and three blades.
| Identifier | ExFiles\Box 75\3\ scan0131 | |
| Date | 18th September 1924 | |
| X.3438 To R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} from EFC. c. GJ. & PN.{Mr Northey} c. EY. DA.{Bernard Day - Chassis Design} EP.{G. Eric Platford - Chief Quality Engineer} c. RG.{Mr Rowledge} WDY. EFC/T18.9.24. X1017 BENCH EXPERIMENTS ON 40/50 STANDARD SIX-BLADED RADIATOR FAN AND ON THE SAME FAN WITH THREE BLADES REMOVED. X3438 (1) Power required to drive fan at various speeds. The fan was suitably mounted on the edge of one of our cast iron tables, and in such a way that the air delivered by the fan was blown across the table. the obstruction to the free air flow being roughly represented in the sketch:- [Sketch labels: ANEMOMETER, FRONT ELEVATION, SIDE ELEVATION, ANEMOMETER, PLAN] The fan was driven by an electric motor of suitable power, electrically arranged in such a way that reasonably accurate measurements of power delivered from the motor pulley could be determined. (N.B. The principle of this power determination is that at each selected motor speed a constant field current is maintained and the motor armature volts and amperes observed both when driving the fan and when running light. From these figures the generated or back E.M.F. of the armature can be determined, and this, when multiplied by the armature current, gives the electrical power converted into mechanical of the motor running light can be subtracted from the power power. Then the power, so estimated when driving the fan | ||