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).
The difficulties of on-road cooling system tests and the development of new methods for comparing radiator efficiency.
| Identifier | ExFiles\Box 24\4\ Scan278 | |
| Date | 21th November 1924 guessed | |
| RADIATOR COMPARISON. The fundamental difficulties which have hitherto mitigated against satisfactory tests of the cooling system on the road are (a) Difficulty of obtaining the absolute Value of any improvement; all hill climbing tests as normally carried out give purely relative values for the particular hill in question. (b) Difficulty of compensating for difference in Ats. conditions when the tests are carried out on different days. The following tests were evolved to obtain radiator efficiencies in absolute units, and so enable any alteration to the system to be expressed as percentage increas or decrease in the in-the capacity of that system to dissipate heat. In the course of these tests it was found that the results could be reasonably accurately obtained no matter what the prevailing atmospheric conditions at the time of the test might be. Two entirely different methods were adopted, and it will be observed that the results obtained by each method are in very close agreement. Method 'A' In these tests a cooling curve was obtained for the system in various conditions. The method adopted was to bring the top water temp. in the radiator to 90°C with the car stationary. The car was then towed at a fixed speed in top gear, the ignition switched off, the water contd:- | ||