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).
Road test results comparing standard radiator tubes with new indented tubes for improved cooling efficiency.
| Identifier | WestWitteringFiles\J\February1923\ Scan41 | |
| Date | 2nd February 1923 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c.c. to CJ. c.c. to E.{Mr Elliott - Chief Engineer} c.c. to Ds. c.c. to BY.{R.W. Bailey - Chief Engineer} ORIGINAL. Hs{Lord Ernest Hives - Chair}5/LG7.2.23. RADIATOR TUBES. X4407 Sometime ago we saw in the American Technical Journals that the efficiency of the radiator could be increased materially if the tubes were made with small indents in them. The theory is that it caused a turbulence in the air passing through the tubes. We considered the claims logical and built up a radiator with tubes having these small indents. We have carried out tests on the road comparing two identical radiators, the only difference being that one set of tubes had indents and the other was standard. From an average of a number of tests on the road, the water temperature is 6 to 7% lower with the indented tubes. As this advantage is gained without any increase in weight or increase in surface, we consider it very valuable and desirable. We attach samples of tubes upon which we have made a comparison. We have used the copper extruded tubes for comparison so as not to use up good stock of standard tubes. Hs.{Lord Ernest Hives - Chair} | ||