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).
Calculations relating to Compression Pressures, Volumetric Efficiency and air flows.
| Identifier | ExFiles\Box 17\6\ Scan147 | |
| Date | 24th August 1933 guessed | |
| -4- Calculations relating to Compression Pressures, Volumetric Efficiency and air flows. (1) Calculations of Vol. Efficiency from compression pressure:- clearance vol = 301.5 cc ( 5.5:1 C.R.) S swept vol = 1356.0 cc Set P = compression pressure - absolute. V = vol compressed gas would, occupy at atmospheric pressure PA{Mr Paterson} ∴ P x (301.5)^1.4 = PA{Mr Paterson} x V^1.4 or V^1.4 = (P/PA{Mr Paterson}) x (301.5)^1.4 ∴ log V = (1/1.4) log (P/PA{Mr Paterson}) + log 301.5 Hence V Volumetric efficiency = ((V - 301.5) / 1356) x 100 E.83906 Large inlet valve head. Speed. | Compress. Press. (lbs/sq.in. gauge) | Atmos. press. lbs.sq.in. abs. | Volumetric efficiency. | Air/min. (cu. ft/min) 3500 | 100 | 14.52 | 75.5 | 63.2 3250 | 105.5 | 14.52 | 78.8 | 61.3 3000 | 110.5 | 14.52 | 81.5 | 58.2 2750 | 114.5 | 14.52 | 83.9 | 55.2 2500 | 115.5 | 14.52 | 84.5 | 53.5 | ||