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).
Tests to determine the power absorbed by three different types of cooling fans on a Bentley unit.
| Identifier | ExFiles\Box 135\1\ scan0034 | |
| Date | 16th September 1933 | |
| X1509 FILES. ------- 16.9.33. ------- X324 POWER ABSORBED BY VARIOUS COOLING FANS (BENTLEY). We have recently made tests to determine the power absorbed by three different types of cooling fans on a Bentley unit. The types of fans used were :- (1) Standard 25 HP. Fan. (2) Peregrine Fan. (3) Chrysler Fan. The test bed unit was fitted with a radiator and bonnet so that the conditions of the test should be as near to those obtained with the unit in chassis. The near end of the bonnet was blanked up to represent the dashboard on the car. The power developed at 4000 r.p.m. (Power peak) with the test bed silencer and using no fan was 102.6 HP. and at 4250 r.p.m. 102.0 HP. With standard 25 HP. fan the power developed at 4000 & 4250 r.p.m. was 97.2 and 96.2 respectively representing a power loss of 5.4 HP. and 5.8 HP. or 5.26% and 5.68%. With the Peregrine fan the power loss at these speeds was 1.8 HP. and 2.2 HP. or 1.75% and 2.16%. The Chrysler fan absorbed at these speeds 1.4 HP. and 1.8 HP. or 1.36% and 1.76% of the power developed when using no fan. The results were identical with the above when the shutters were closed, the account for this is due to the fact that no undershields or sideshields were used, so that a considerable amount of air could be drawn from underneath the radiator and bonnet. The power loss is affective over a considerable speed range and at 1500 r.p.m. there is a loss of 3.1 MEP. when using the standard 25 HP. Fan or 2.68%. The losses at 1500 r.p.m. with the other fans are as follows- Peregrine 2.8 MEP. or 2.42% Chrysler 2.0 MEP. or 1.73% R.Matthews. | ||