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 for compression pressures, volumetric efficiency, and air flows with test data for a large inlet valve head.
| Identifier | ExFiles\Box 88\4\ scan0025 | |
| 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.) 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) x 100 / 1356 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 115.0 14.52 84.0 50.5 | ||