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).
Graph comparing the performance of various standard and experimental engine cooling fans, plotting speed and power against axial thrust.
| Identifier | ExFiles\Box 66a\4\ scan0040 | |
| Date | 18th March 1925 | |
| NOS. & DESCRIPTIONS OF FANS. Fan tip diameter. (1) Std. 40/50 6-bladed fan. 22" (3) Original EAC. 4-bladed fan. 23" (9) Better of the two fans made as far as possible to recommendations by Prof. Watts. 22" (10) Expl. EAC. fan. 1st Modification as previously reported (See Expl/X17.12.24). 23" (14) Last expt. on (10) previous to reduction of fan tip dia. 23" (15) (Points only - marked ☉) Fan of reduced tip dia. made up to tentative, best shape and handed to D.O. for instr. for EAC. production. 22" (16) (Points only - marked □) Wider bladed expl. fan, 1st. modification. 22" (17) (Points only - marked ∆) Wider bladed expl. fan, 2nd. modification. 22" (18) (Full curve) Wider bladed expl. fan. 3rd Modfn. this being considered to be the finally best form of fan producible of this dia. from sheet material. 22" Y-Axis Left: FAN SPEED (RPM) Y-Axis Right: MOTOR OR ENGINE POWER REQUIRED TO DRIVE FAN (HP) X-Axis: AXIAL THRUST OF FAN IN LBS WEIGHT Graph Labels: SPEED, POWER Curve Numbers: 1, 3, 9, 10, 14, 18 Point markers: ☉ (15), □ (16), ∆ (17) Top Right: H Bottom Right: H.E.W. 18-3-25 E.P.C. 193 | ||