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).
Description of radiator cooling testing methods based on Newton's Law, including 'Method 'B''.
| Identifier | ExFiles\Box 24\4\ Scan280 | |
| Date | 21th November 1924 guessed | |
| -3- When corrections have been made for these variables due to the method of testing, the cooling curves follow Newtons Law. The factor 'A' can therefore be obtained for any given condition of the radiator. Values of 'A' where 'A' is the drop in temp. of the system per min per F° difference in temp. between the atmospheric and mean radiator temp. are given showing the benefit to be derived from ventilation and fan. METHOD 'B'. Having established that the cooling of the radiator follows Newtons Law, it follows that δT the difference in temp. between the mean rad. temp. and atmosphere required to dissipate a fixed quantity of heat units per min. will indicate directly the efficiency of the sy stem. That is, if one radiator will dissipate the heat generated on full throttle at 30 m.p.h., when = 70°C, and another necessitates being 80°C to get rid of the same quantity of heat, then the first radiator shews a gain of efficiency of 14% over the second. S δ 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 or the radiator will take up a fixed temp. indirectly 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 temp. and air temp. will indicate the required δT to accomplish this for the particular system being tested. | ||