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).
Letter to The British Thermostat Co.Ltd. discussing a discrepancy in radiator core performance data and calculations.
| Identifier | ExFiles\Box 156\1\ scan0155 | |
| Date | 23th January 1936 | |
| X1328 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Std.10/KW. 23rd January, 1936. The British Thermostat Co.Ltd., Windmill Road, Sunbury, Middlesex. For the attention of Capt. Payne. Dear Capt. Payne, Many thanks for the curves enclosed with your letter of the 9th inst. These are very interesting, and indicate that the Morris type of core is slightly superior to the Vauxhall type at the higher car speeds, for the same size of block. There is one detail which puzzles us, however. If one calculates the curve of B.T.U's/hr/sq.' cooling surface/°F.{Mr Friese} temp. diff. (against quantity of air passing) from the curves given of H.P. dissipated/sq.' of frontal area, the curve so obtained does not agree with that given on separate sheet; e.g., taking the Vauxhall radiator as an example, from Chart L/592B, the H.P./sq.' frontal area dissipated at 1500 cu.ft/min/sq.' frontal area, with a temp. difference of 100°F.{Mr Friese}, is 19.8 H.P. Converting this to B.T.U's/hr/sq.' cooling surface/°F.temp.diff., we have - Heat = (19.8) x 42.4 x 60 / 28.5 x 100 = 17.7 B.T.U's/hr/sq.' cooling surface/°F.temp. difference. but from chart L/572A, the figure obtained at 1500 cu.ft./min/sq.' frontal area is 21.0 B.T.U's/hr/sq.' cooling surface/°F.{Mr Friese} temp. diff. | ||