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).
Tests of different radiator tube designs to improve cooling efficiency.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan115 | |
| Date | 14th October 1930 | |
| -2- Hs{Lord Ernest Hives - Chair}/Ad/A.14.10.30 contd. confirming the figures in this test as though they are comparative we suspect that the car's performance was not 100%. We had hoped for over 10° improvement from this square tube radiator, and from other tests here reported we can only think that by going to a plain parallel tube we may have lost some turbulence ordinarily promoted by the expanded ends. There will be a saving of weight over standard on this radiator in its final form. (2) Standard Turbulent Air Flow Tubes 6/7s. These tubes were exactly the same as the standard tube except that four hemi-spherical bulges .020" deep were made at regular intervals in its length. The object of this test was (1) To determine whether a small amount of turbulence has an appreciable effect on the efficiency of a tube. (2) To ascertain if anything could be done to improve radiators being made. The results are most surprising and naturally require confirmation. So far they indicate that we can improve the standard radiator from 5° to 6.5°C. by this modification. We are carrying out low speed full throttle tests. (3) 5/7 mms. expanded square tubes. This test confirms that at 60 M.P.H. there is little if any difference between this and the 5 1/2 / 7 mm. round tube. | ||