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 detailing the method of testing a tuned resonance chamber air silencer.
| Identifier | ExFiles\Box 123\1\ scan0123 | |
| Date | 7th September 1938 | |
| -2- As you probably know, we use a tuned resonance chamber type of air silencer, inside which was fitted a coil of copper tubing, which took the shape of and replaced the normal centre tube of the silencer. By passing either, cold water, compressed air, or steam through the coil, we could control the intake air temperature (measured at the carburetter inlets) between the temps. of 20° and 55°C. Care was naturally taken to ensure that all parts affected by conducted heat, which would influence the test, were allowed to reach a stable temperature. The result of this test we have already stated in our previous letter, but as we wish to make use of any information which might be forthcoming from your cooperation, we have explained in more detail the method of our test. We might add that our normal under bonnet temperature on the Bentley car is around 40 - 45°C. so we would say that if we used your unit, its source of air supply would have to have some connection with the outside of the bonnet. Hoping to hear more from you on this subject. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||