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 on the velocity of air passing through a radiator with varying engine speeds and shutter positions.
| Identifier | ExFiles\Box 78\3\ scan0057 | |
| Date | 25th February 1915 guessed | |
| Wor{Arthur Wormald - General Works Manager}/EH2/L.25215. 4. Air velocity - 600ft per min. Air velocity 1500ft per min. Air Velocity 2000 ft per min. Radius of the Fan. Velocity of Air passing through Radiator at a certain point. Engine Revs. | Shutters closed | Shutters open | Remarks. --- | --- | --- | --- 500 | 850 ft per min. | 920 ft per min. | Taken on std. square honey-comb radiator. 1000 | 1380 " " " | 1500 " " " | 1500 | 2000 " " " | 2100 " " " | 2000 | 2500 " " " | 2700 " " " | I measured the velocity of the air passing out of the front shutters, it was 3075 feet per minute, the air was going through the radiator at 2000 ft per min., this also proves the building up of pressure under the bonnet even when all the shutters are open. The front shutters let out more air than the rear ones. Our tests are not actual road conditions because the air from under the bonnet would not | ||