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).
Radiator tests, comparing different matrix sizes and analyzing airflow under the bonnet.
| Identifier | ExFiles\Box 78\3\ scan0056 | |
| Date | 25th February 1915 guessed | |
| Wor{Arthur Wormald - General Works Manager}/EH2/L25215. 3. The most important point these tests prove is that the baffling point of the air is under the bonnet, the air is not restricted passing through the radiator. This point is shown up very clearly on No.1 chart, with the difference the shutters being open make to a radiator with the 5" matrix compared with another with a 3.5" matrix, it shows a marked improvement with the shutters open with the wide matrix and only very little improvement with the narrow one. This means that we can never attempt to use a narrower radiator, it also shows that there is no question of the wide radiator being inefficient because of it being baffled. When the car was running on the dynamometer I measured the velocity of the air passing through the radiator with an anemometer, it is an instrument which is used to measure the velocity of the wind on the Renault test rig. In the first place we found that the velocity of the air through the radiator at different points varied considerably, in the corners the air is actually forced out from under the bonnet. The test below was taken with the engine running at 1500 revs. shutters closed. | ||