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).
Page with a table of induction pipe and air temperatures at different RPMs and heating conditions, followed by analysis on hot spot temperature's effect on power and efficiency.
| Identifier | ExFiles\Box 66a\1\ scan0094 | |
| Date | 2nd February 1926 guessed | |
| contd :- -9- | | Std. exh. heated. | Water heated. | Superheated. | |---|---|---|---|---| | R.P.M. | Indn pipe temp. oC. | Air oC. | Indn pipe temp. oC. | Air oC. | Indn pipe temp. oC. | Air oC. | | 750 | 31.5 | 35 | 31 | 25 | 33.5 | 38 | | 1000 | 30 | 37 | 27 | 30 | -- | -- | | 1500 | 31.5 | 46 | 28 | 35 | 29 | 37.5 | | 2000 | 26 | 35 | 25.5 | 38 | -- | -- | It seems that when a certain critical temperature is reached any extra pre-heating only goes to supply the latent heat without any resulting temperature increase in the induction pipe. Of course, for a greater heat input, the final charge temperature in the cylinder must naturally be higher. Notwithstanding the above statement, we should imagine that if the relative heat input of the exhaust and water system was of proportional magnitude to the average temperatures of these heating mediums we should expect in the former case to find higher induction temperatures than actualy recorded because sufficient heat would not only completely evaporate the charge but also raise the temperature of the resulting gas. INFLUENCE OF HOT SPOT TEMPERATURE ON POWER & EFFICIENCY. The following tests were made in an endeavour to show how the power and efficiency were influenced by each of the three systems when operating normally at full load. Speeds of 1500 and 750 r.p.m. were selected, the lower one so that the value of the heating system in correcting dis-tribution - which was naturally worse at low speeds than at high - could be estimated. contd :- | ||