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 guide vane angles and a description of supercharger testing methods.
| Identifier | ExFiles\Box 42\3\ Scan049 | |
| Date | 1st December 1926 guessed | |
| contd :- -4- These figures show that considerable losses must take place at the inlet guide vanes. We suggest that we try removing the guide vanes altogether, and also make some up with a varying pitch angle to allow for increasing wheel velocity with dia. Estimation of guide vane angles required. Assuming vanes of negligible thickness. Area of guide vane face = π/4 ( 4.5² - 1.75²) = 13.5 sq. ins Assumed density of air at eye of blower = .0561 lbs/cu.ft. Air velocity normal to plane of wheel = (56 X 144) / (.0561 X 60 X 13.5) = 177 ft/sec. Wheel velocity at outer circumference of guide vanes. = (810 X 4.5) / 9.0 = 405 ft/sec. Ditto - at inner - = (810 X 1.75) / 9.0 = 157 ft/sec. Outside vane angle with plane of wheel = tan⁻¹ (177/405) = 23° 36' Inside vane angle with plane of wheel = tan⁻¹ (177/157) = 48° 27' SUPERCHARGER TESTING METHODS. We give herewith sketch of the rig used for testing F.X. supercharger. We have found it a very reliable and convenient rig. Sufficient D.C. power for the job could not be obtained at the Works and we arranged to drive the supercharger from an engine. Power input is measured from the torque contd:- | ||