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).
Horsepower calculations and a proposal for an evaporative cooling system on a Phantom II engine.
| Identifier | ExFiles\Box 25\1\ Scan006 | |
| Date | 31th October 1929 | |
| LrL/AD31.10.29 contd. -4- of frontal area. . . H.P. spent in drag or resistance to flow in maintaining 7000 ft/sec. air speed = 1.25 x 7000 x 10 / 33000 = 2.65 HP H.P. to move 490 lbs of air/min. at this speed = 490 x (7000 / 60)^2 / (33000 x 2g) = 3.15 HP Total air horse power = 5.8 HP assuming 75% efficiency B.H.P. = 7.75 The existing fan on Phantom II takes 3 B.H.P. . . additional power to drive = 3.75 B.H.P. A diagrammatic arrangement of the system is shown on the sketch, which is not intended to represent the relative positions of cooling plant in the tank. I would suggest we run a Phantom II engine under evaporatively cooled conditions at an early date if there is any likelihood of the proposal materialising. Lr.{Mr Ellor} | ||