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).
Analysis of cooling test data and radiator drag for the Fairey 'Battle' aircraft.
| Identifier | ExFiles\Box 10\3\ 03-page004 | |
| Date | 22th December 1938 | |
| SUBJECT: Fairey "Battle". Cooling Test. With reference to the recent test on this machine, our representative has reported that for a given radiator flap position, considerably more boost was required to maintain level flight than on a previous occasion. We have no definite information on this point, but in view of the fact that it is known that the engine has recently been changed, it is possible that there has been an alteration in airscrew blade angles. The purpose of this letter is to put forward some observations on the figures obtained during the first test. It would be appreciated if these could be checked at the earliest possible opportunity, as it appears that if our assumptions are correct, there is some definite evidence that the drag of the complete radiator installation is appreciably affected by the quantity of air passing through the duct. At present we have no means of measuring the internal drag of the duct, and any information which would enable us to estimate this would be of the utmost value. On page 1 of report No. B.S.604, some curves are given showing the boost required to maintain level flight at various speeds. From these curves and using the data given in report No. B.S.663, it is possible to calculate the drag of the complete machine. It is appreciated that in arriving at these figures, a number of assumptions have had to be made which have not yet been fully substantiated. A curve has been prepared (Drg. No. T.34382) which shows the increase in overall drag against the boost required to maintain level flight. A similar curve (Drg. No. S.32420) has also been prepared, showing the same data for a different installation. | ||