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).
Methods for comparing radiator cooling efficiencies.
| Identifier | ExFiles\Box 22\1\ Scan210 | |
| Date | 25th November 1924 | |
| R.R. 493A (20H) (D.A. 652 20-3-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF:Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/LG25.11.24. RADIATOR COMPARISONS. 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 atmospheric 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 a percentage increase or decrease 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 - the results in each case 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 temperature in the radiator to 90°C with the car stationary. The car was then towed at a fixed speed in the top gear, the ignition switched off, the water contd :- | ||