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).
Test report comparing the efficiency of a three-bladed fan versus a standard fan on a 35-PK model.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan32 | |
| Date | 29th June 1924 | |
| COPY. Chateauroux, June 29th. 1924. FAN TESTS ON 35-PK. Conditions of tests. Full throttle, braking down to required speed. All tests taken under exactly similar conditions as regards roads and direction of motion. T1 = Temp. at start of run in °C. T2 = " " finish " " T2 - T1 = Increase in engine temp. during test. Air temp. during tests = 23.75°C. Bonnet Shutters open. FAN WITH THREE BLADES. | T1 | T2 | T2 - T1 | Dist: miles. | Speed m.p.h. | |-------|--------|---------|--------------|--------------| | 85° | 97° | 12° | 1 | 20 | | 85° | 97.5° | 12.5° | 1 | 30 | | 85° | 91.5° | 6.5° | 1 | 40 | | 85° | 90.5° | 5.5° | 1 | 50 | | 85° | 91° | 6° | 3 | 60 | STANDARD FAN. | T1 | T2 | T2 - T1 | Dist: miles. | Speed m.p.h. | |-------|--------|---------|--------------|--------------| | 85° | 94.5° | 9.5° | 1 | 20 | | 85° | 93° | 8° | 1 | 30 | | 85° | 91.5° | 6.5° | 1 | 40 | | 85° | 89° | 4° | 1 | 50 | | 85° | 94° | 9° | 3 | 60 | The above tests shew a slight increase in efficiency of the three bladed fan over the standard one at high speeds. The reverse being the case at low speeds. Hs{Lord Ernest Hives - Chair}/AJL. | ||