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).
Difficulties encountered with the Daley-Watson Indicator and potential solutions.
| Identifier | ExFiles\Box 79\3\ scan0101 | |
| Date | 21th September 1918 | |
| R.R. 235a (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. To EFC. from R.{Sir Henry Royce} c. to CJ. 21st. Septembr, 1918. R2/G21918. X.3181 - RE DALEY-WATSON INDICATOR The difficulties I remember of the Watsom Indicator were as follows:- The apparatus had to be extremely close to the engine because of the inertia of the air in the pipe connecting the diaphragm with the engine cylinder We shall be glad to know if there has been any modification concerning the views on this particular point. The second point of difficulty appeared to be that owing to the close proximity of the pressure diaphragm to the engine cylinder, and the free connection necessary, it was found that the diaphragm got very hot, and not only read incorrectly, but got softened and broke in next to no time. I understand, however, that Dr. Watson discovered the vibrations in the pipe could be damped out by the use of a spiral of copper wire in the pipe. Now if this would permit of a reasonably long pipe between the engine cylinder and the diaphragm, I can understand the trouble with the diaphragms would be overcome. We shall be pleased to help Messrs. Cussons all that it is possible by letting them experiment at our Works, as we can give them the actual pressure from the cylinder of an engine running, probably with the highest mean pressure and explosive pressure and highest number of revolutions as any aero engine is likely to do for some time to come. I mean by this Contd. | ||