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).
Method for testing radiator performance by simulating hill climbing on a level road.
| Identifier | ExFiles\Box 38\2\ Scan260 | |
| Date | 25th November 1924 | |
| -3- EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/LG25.11.24. To obtain δt for any radiator the car was driven at full throttle towing a second car in a low gear, the object of this being to keep the road speed down to any required limit. After running for a certain distance like this, the towing car will either boil - in which case the first method must be used - or the radiator will take up a fixed temperature indicating that the heat dissipated by the cooling system at the speed in question just balances the heat given out by the engine at this speed on full throttle. Readings of the top and bottom water temperature and air temperature will indicate the δt required to accomplish this for the particular system being tested. This method is exactly equivalent to reproducing hill climbing conditions on the level. As in every case, the prevailing atmospheric temperature is subtracted from the mean radiator temperature attained, δt is a figure entirely independent of the climatic conditions at the time of the test. For the purpose of comparisons we have converted the δt figures into critical atmospheric temperatures. The critical atmospheric temperature is the temperature at which the car will boil if driven for sufficiently long on full throttle at the speed and under the conditions prevailing in the test. It is obtained as follows :- The difference between the top and bottom radiator water temperatures is approx. 10°C, it actually varies slightly with the speed. When therefore the mean radiator temperature gets to 95°C, the car will be boiling. contd :- | ||