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).
Theoretical analysis of motor efficiency using ratios of electromotive forces, magnetic fluxes, and torques.
| Identifier | ExFiles\Box 61b\3\ scan0103 | |
| Date | 15th July 1929 guessed | |
| -3- Contd. The other six quantities introduced, e.g. the two E.M.F's es and er, the two fluxes per pole ØE and Ør and the two torques TE and Te are considered to be related to the other quantities in their respective columns by the same two general relations between the E.M.F's and fluxes, and between torque and flux respectively, so that the 12 quantities as above exhibited are proportional both in rows and in columns. It follows from the fact that the two general relations are the expression of fundamental principles, that the overall efficiency of the motor is expressible as either of the three ratios er/E Ør/ØE Tr{Capt. F. W. Turner - Finance}/TE and that the overall efficiency is also expressible as es/E x Tr{Capt. F. W. Turner - Finance}/Ts = ( ee/E x Øs/Øe x Tr{Capt. F. W. Turner - Finance}/Ts ) or again, as Øs/ØE x Ør/Øs = (Øe/ØE x Øs/Øe x Ør/Øs) which = Ør/ØE from which it will be seen that observations of generated E.M.F. under condition (2) above, and of static torque under (3) above, enable us, in conjunction with the results of the brake test, to analyse, for each current value, the efficiency of the motor mainly into two components efficiencies: | ||